[ { "key": "8BTR98GT", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/8BTR98GT", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/8BTR98GT", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Ghan et al.", "parsedDate": "2013-06-27", "numChildren": 0 }, "data": { "key": "8BTR98GT", "version": 98, "itemType": "journalArticle", "title": "A simple model of global aerosol indirect effects", "creators": [ { "creatorType": "author", "firstName": "Steven J.", "lastName": "Ghan" }, { "creatorType": "author", "firstName": "Steven J.", "lastName": "Smith" }, { "creatorType": "author", "firstName": "Minghuai", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Kai", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Kirsty", "lastName": "Pringle" }, { "creatorType": "author", "firstName": "Kenneth", "lastName": "Carslaw" }, { "creatorType": "author", "firstName": "Jeffrey", "lastName": "Pierce" }, { "creatorType": "author", "firstName": "Susanne", "lastName": "Bauer" }, { "creatorType": "author", "firstName": "Peter", "lastName": "Adams" } ], "abstractNote": "Most estimates of the global mean indirect effect of anthropogenic aerosol on the Earth's energy balance are from simulations by global models of the aerosol lifecycle coupled with global models of clouds and the hydrologic cycle. Extremely simple models have been developed for integrated assessment models, but lack the flexibility to distinguish between primary and secondary sources of aerosol. Here a simple but more physically based model expresses the aerosol indirect effect (AIE) using analytic representations of cloud and aerosol distributions and processes. Although the simple model is able to produce estimates of AIEs that are comparable to those from some global aerosol models using the same global mean aerosol properties, the estimates by the simple model are sensitive to preindustrial cloud condensation nuclei concentration, preindustrial accumulation mode radius, width of the accumulation mode, size of primary particles, cloud thickness, primary and secondary anthropogenic emissions, the fraction of the secondary anthropogenic emissions that accumulates on the coarse mode, the fraction of the secondary mass that forms new particles, and the sensitivity of liquid water path to droplet number concentration. Estimates of present-day AIEs as low as −5 W m−2 and as high as −0.3 W m−2 are obtained for plausible sets of parameter values. Estimates are surprisingly linear in emissions. The estimates depend on parameter values in ways that are consistent with results from detailed global aerosol-climate simulation models, which adds to understanding of the dependence on AIE uncertainty on uncertainty in parameter values.", "publicationTitle": "Journal of Geophysical Research: Atmospheres", "publisher": "", "place": "", "date": "June 27, 2013", "volume": "118", "issue": "12", "section": "", "partNumber": "", "partTitle": "", "pages": "6688-6707", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JGR-Atmos", "DOI": "10.1002/jgrd.50567", "citationKey": "ghanSimpleModelGlobal2013", "url": "http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50567/abstract", "accessDate": "2014-09-11T17:55:58Z", "PMID": "", "PMCID": "", "ISSN": "2169-8996", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2013. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "3305 Climate change and variability", "type": 1 }, { "tag": "3311 Clouds and aerosols", "type": 1 }, { "tag": "3320 Idealized model", "type": 1 }, { "tag": "3367 Theoretical modeling", "type": 1 }, { "tag": "aerosol", "type": 1 }, { "tag": "climate", "type": 1 }, { "tag": "cloud", "type": 1 }, { "tag": "indirect", "type": 1 }, { "tag": "interactions", "type": 1 } ], "collections": [ "ABEVT668", "QZ3S7D5I" ], "relations": {}, "dateAdded": "2014-09-11T17:55:58Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "PRPSJRI9", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/PRPSJRI9", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/PRPSJRI9", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Christensen et al.", "parsedDate": "2014-09-01", "numChildren": 0 }, "data": { "key": "PRPSJRI9", "version": 98, "itemType": "journalArticle", "title": "Ship-track Observations of a Reduced Shortwave Aerosol Indirect Effect in Mixed-Phase Clouds", "creators": [ { "creatorType": "author", "firstName": "M.", "lastName": "Christensen" }, { "creatorType": "author", "firstName": "K.", "lastName": "Suzuki" }, { "creatorType": "author", "firstName": "B.", "lastName": "Zambri" }, { "creatorType": "author", "firstName": "G. L.", "lastName": "Stephens" } ], "abstractNote": "Aerosol influences on clouds are a major source of uncertainty to our understanding of forced climate change. Increased aerosol can enhance solar reflection from clouds countering greenhouse gas warming. Recently this indirect effect has been extended from water droplet clouds to other types including mixed-phase clouds. Aerosol effects on mixed-phase clouds are important because of their fundamental role on sea-ice loss and polar climate change but very little is known about aerosol effects on these clouds. Here we provide the first analysis of the effects of aerosol emitted from ship stacks into mixed-phase clouds. Satellite observations of solar reflection in numerous ship tracks reveal that cloud albedo increases 5 times more in liquid clouds when polluted and persist 2 hours longer than in mixed-phase clouds. These results suggest that seeding mixed-phase clouds via shipping aerosol is unlikely to provide any significant counterbalancing solar radiative cooling effects in warming polar regions.", "publicationTitle": "Geophysical Research Letters", "publisher": "", "place": "", "date": "September 1, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "2014GL061320", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "GRL", "DOI": "10.1002/2014GL061320", "citationKey": "christensenShiptrackObservationsReduced2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/2014GL061320/abstract", "accessDate": "2014-09-11T17:55:34Z", "PMID": "", "PMCID": "", "ISSN": "1944-8007", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2014. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "0321 Cloud/radiation interaction", "type": 1 }, { "tag": "3311 Clouds and aerosols", "type": 1 }, { "tag": "CALIPSO", "type": 1 }, { "tag": "CloudSat", "type": 1 }, { "tag": "indirect effect", "type": 1 }, { "tag": "mixed-phase", "type": 1 }, { "tag": "ship tracks", "type": 1 }, { "tag": "stratocumulus", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:55:34Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "3SM5SQRG", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/3SM5SQRG", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/3SM5SQRG", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Chen et al.", "parsedDate": "2014-09", "numChildren": 0 }, "data": { "key": "3SM5SQRG", "version": 98, "itemType": "journalArticle", "title": "Satellite-based estimate of global aerosol-cloud radiative forcing by marine warm clouds", "creators": [ { "creatorType": "author", "firstName": "Yi-Chun", "lastName": "Chen" }, { "creatorType": "author", "firstName": "Matthew W.", "lastName": "Christensen" }, { "creatorType": "author", "firstName": "Graeme L.", "lastName": "Stephens" }, { "creatorType": "author", "firstName": "John H.", "lastName": "Seinfeld" } ], "abstractNote": "Changes in aerosol concentrations affect cloud albedo and Earth’s radiative balance. Aerosol radiative forcing from pre-industrial time to the present due to the effect of atmospheric aerosol levels on the micro- and macrophysics of clouds bears the largest uncertainty among external influences on climate change. Of all cloud forms, low-level marine clouds exert the largest impact on the planet’s albedo. For example, a 6% increase in the albedo of global marine stratiform clouds could offset the warming that would result from a doubling of atmospheric CO2 concentrations. Marine warm cloud properties are thought to depend on aerosol levels and large-scale dynamic or thermodynamic states. Here we present a comprehensive analysis of multiple measurements from the A-Train constellation of Earth-observing satellites, to quantify the radiative forcing exerted by aerosols interacting with marine clouds. Specifically, we analyse observations of co-located aerosols and clouds over the world’s oceans for the period August 2006–April 2011, comprising over 7.3 million CloudSat single-layer marine warm cloud pixels. We find that thermodynamic conditions—that is, tropospheric stability and humidity in the free troposphere—and the state of precipitation act together to govern the cloud liquid water responses to the presence of aerosols and the strength of aerosol–cloud radiative forcing.", "publicationTitle": "Nature Geoscience", "publisher": "", "place": "", "date": "September 2014", "volume": "7", "issue": "9", "section": "", "partNumber": "", "partTitle": "", "pages": "643-646", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "NatGeosci", "DOI": "10.1038/ngeo2214", "citationKey": "chenSatellitebasedEstimateGlobal2014", "url": "http://www.nature.com/ngeo/journal/v7/n9/full/ngeo2214.html", "accessDate": "2014-09-11T17:55:11Z", "PMID": "", "PMCID": "", "ISSN": "1752-0894", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "www.nature.com", "callNumber": "", "rights": "© 2014 Nature Publishing Group", "extra": "", "tags": [], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:55:11Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "DUXXC3Q2", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/DUXXC3Q2", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/DUXXC3Q2", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Li et al.", "parsedDate": "2014-08-01", "numChildren": 0 }, "data": { "key": "DUXXC3Q2", "version": 98, "itemType": "journalArticle", "title": "Characterizing the radiative impacts of precipitating snow in the ECMWF Integrated Forecast System global model", "creators": [ { "creatorType": "author", "firstName": "J.-L. F.", "lastName": "Li" }, { "creatorType": "author", "firstName": "R. M.", "lastName": "Forbes" }, { "creatorType": "author", "firstName": "D. E.", "lastName": "Waliser" }, { "creatorType": "author", "firstName": "G.", "lastName": "Stephens" }, { "creatorType": "author", "firstName": "Seungwon", "lastName": "Lee" } ], "abstractNote": "Global weather and climate models often exclude the effects of precipitating hydrometeors and convective core mass on radiative fluxes. In particular, many models split the ice phase into separate “cloud ice” and “snow” categories representing the smaller and larger ice particles, respectively; a separation that is generally not well defined in observations. A version of the European Centre for Medium-Range Weather Forecasts (ECMWF) global numerical weather prediction model which includes the radiative effects of cloud liquid, cloud ice, and precipitating snow is used to investigate the impact of including and excluding the radiative effects of the precipitating snow category. The results show that exclusion of precipitating snow in the radiation calculations leads to differences in the shortwave and longwave radiative fluxes of 5–15 W m−2 in strongly precipitating and convective areas. These differences are of the same order of magnitude as the systematic errors in the model compared to satellite observations. Corresponding biases in the radiative heating profiles are on the order of 0.15 K d−1. The results imply that precipitating snow should be included in the radiative calculations in all weather and climate models in the context of improving model fidelity and reducing compensating errors.", "publicationTitle": "Journal of Geophysical Research: Atmospheres", "publisher": "", "place": "", "date": "August 1, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "2014JD021450", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JGR-Atmos", "DOI": "10.1002/2014JD021450", "citationKey": "liCharacterizingRadiativeImpacts2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/2014JD021450/abstract", "accessDate": "2014-09-11T17:54:21Z", "PMID": "", "PMCID": "", "ISSN": "2169-8996", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2014. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "3337 Global climate models", "type": 1 }, { "tag": "3354 Precipitation", "type": 1 }, { "tag": "3359 Radiative processes", "type": 1 }, { "tag": "3371 Tropical convection", "type": 1 }, { "tag": "3373 Tropical dynamics", "type": 1 }, { "tag": "ECMWF IFS", "type": 1 }, { "tag": "cloud-radiation", "type": 1 }, { "tag": "forecast GCM", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:54:21Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "GW4WQ68N", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/GW4WQ68N", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/GW4WQ68N", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Chen and Tung", "parsedDate": "2014-08-22", "numChildren": 0 }, "data": { "key": "GW4WQ68N", "version": 98, "itemType": "journalArticle", "title": "Varying planetary heat sink led to global-warming slowdown and acceleration", "creators": [ { "creatorType": "author", "firstName": "Xianyao", "lastName": "Chen" }, { "creatorType": "author", "firstName": "Ka-Kit", "lastName": "Tung" } ], "abstractNote": "A vacillating global heat sink at intermediate ocean depths is associated with different climate regimes of surface warming under anthropogenic forcing: The latter part of the 20th century saw rapid global warming as more heat stayed near the surface. In the 21st century, surface warming slowed as more heat moved into deeper oceans. In situ and reanalyzed data are used to trace the pathways of ocean heat uptake. In addition to the shallow La Niña–like patterns in the Pacific that were the previous focus, we found that the slowdown is mainly caused by heat transported to deeper layers in the Atlantic and the Southern oceans, initiated by a recurrent salinity anomaly in the subpolar North Atlantic. Cooling periods associated with the latter deeper heat-sequestration mechanism historically lasted 20 to 35 years.\nDeep-sea warming slows down global warming\nGlobal warming seems to have paused over the past 15 years while the deep ocean takes the heat instead. The thermal capacity of the oceans far exceeds that of the atmosphere, so the oceans can store up to 90% of the heat buildup caused by increased concentrations of greenhouse gases such as carbon dioxide. Chen and Tung used observational data to trace the pathways of recent ocean heating. They conclude that the deep Atlantic and Southern Oceans, but not the Pacific, have absorbed the excess heat that would otherwise have fueled continued warming.\nScience, this issue p. 897", "publicationTitle": "Science", "publisher": "", "place": "", "date": "08/22/2014", "volume": "345", "issue": "6199", "section": "", "partNumber": "", "partTitle": "", "pages": "897-903", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Science", "DOI": "10.1126/science.1254937", "citationKey": "chenVaryingPlanetaryHeat2014", "url": "http://www.sciencemag.org/content/345/6199/897", "accessDate": "2014-09-08T23:56:43Z", "PMID": "", "PMCID": "", "ISSN": "0036-8075, 1095-9203", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "www.sciencemag.org", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [ "B2WZSKGV" ], "relations": { "owl:sameAs": "http://zotero.org/groups/285990/items/U2Q7SV47" }, "dateAdded": "2014-09-10T02:31:22Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "RN6HAFVN", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/RN6HAFVN", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/RN6HAFVN", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Park", "parsedDate": "2014-08-08", "numChildren": 0 }, "data": { "key": "RN6HAFVN", "version": 98, "itemType": "journalArticle", "title": "A Unified Convection Scheme, UNICON. Part I. Formulation", "creators": [ { "creatorType": "author", "firstName": "Sungsu", "lastName": "Park" } ], "abstractNote": "AbstractThe author develops a Unified Convection Scheme (UNICON) that parameterizes relative (i.e., with respect to the grid-mean vertical flow) subgrid vertical transport by nonlocal asymmetric turbulent eddies. UNICON is a process-based model of subgrid convective plumes and mesoscale organized flow without relying on any quasi-equilibrium assumptions such as Convective Available Potential Energy (CAPE) or Convective Inhibition (CIN) closures. In combination with a relative subgrid vertical transport scheme by local symmetric turbulent eddies and a grid-scale advection scheme, UNICON simulates vertical transport of water species and conservative scalars without double counting at any horizontal resolution.UNICON simulates all dry-moist, forced-free and shallow-deep convection within a single framework in a seamless, consistent and unified way. It diagnoses the vertical profiles of the macrophysics (fractional area, plume radius and number density) as well as the microphysics (production and evaporation rates of convective precipitation) and the dynamics (mass flux and vertical velocity) of multiple convective updraft and downdraft plumes. UNICON also prognoses subgrid cold pool and mesoscale organized flow within the Planetary Boundary Layer (PBL) that is forced by evaporation of convective precipitation and accompanying convective downdrafts but damped by surface flux and entrainment at the PBL top. The combined subgrid parameterization of diagnostic convective updraft and downdraft plumes, prognostic subgrid mesoscale organized flow, and the feedback among them remedies the weakness of conventional quasi-steady diagnostic plume models - the lack of plume memory across the time step, allowing UNICON to successfully simulate various transitional phenomena associated with convection (e.g., the diurnal cycle of precipitation and the Madden-Julian Oscillation).", "publicationTitle": "Journal of the Atmospheric Sciences", "publisher": "", "place": "", "date": "August 8, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JAS", "DOI": "10.1175/JAS-D-13-0233.1", "citationKey": "parkUnifiedConvectionScheme2014a", "url": "http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-13-0233.1", "accessDate": "2014-09-09T21:11:05Z", "PMID": "", "PMCID": "", "ISSN": "0022-4928", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "journals.ametsoc.org (Atypon)", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-09T21:11:05Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "IS9J6HJV", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/IS9J6HJV", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/IS9J6HJV", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Su et al.", "parsedDate": "2014-05-27", "numChildren": 1 }, "data": { "key": "IS9J6HJV", "version": 98, "itemType": "journalArticle", "title": "Weakening and strengthening structures in the Hadley Circulation change under global warming and implications for cloud response and climate sensitivity", "creators": [ { "creatorType": "author", "firstName": "Hui", "lastName": "Su" }, { "creatorType": "author", "firstName": "Jonathan H.", "lastName": "Jiang" }, { "creatorType": "author", "firstName": "Chengxing", "lastName": "Zhai" }, { "creatorType": "author", "firstName": "Tsaepyng J.", "lastName": "Shen" }, { "creatorType": "author", "firstName": "J. David", "lastName": "Neelin" }, { "creatorType": "author", "firstName": "Graeme L.", "lastName": "Stephens" }, { "creatorType": "author", "firstName": "Yuk L.", "lastName": "Yung" } ], "abstractNote": "It has long been recognized that differences in climate model-simulated cloud feedbacks are a primary source of uncertainties for the model-predicted surface temperature change induced by increasing greenhouse gases such as CO2. Large-scale circulation broadly determines when and where clouds form and how they evolve. However, the linkage between large-scale circulation change and cloud radiative effect (CRE) change under global warming has not been thoroughly studied. By analyzing 15 climate models, we show that the change of the Hadley Circulation exhibits meridionally varying weakening and strengthening structures, physically consistent with the cloud changes in distinct cloud regimes. The regions that experience a weakening (strengthening) of the zonal-mean circulation account for 54% (46%) of the multimodel-mean top-of-atmosphere (TOA) CRE change integrated over 45°S–40°N. The simulated Hadley Circulation structure changes per degree of surface warming differ greatly between the models, and the intermodel spread in the Hadley Circulation change is well correlated with the intermodel spread in the TOA CRE change. This correlation underscores the close interactions between large-scale circulation and clouds and suggests that the uncertainties of cloud feedbacks and climate sensitivity reside in the intimate coupling between large-scale circulation and clouds. New model performance metrics proposed in this work, which emphasize how models reproduce satellite-observed spatial variations of zonal-mean cloud fraction and relative humidity associated with the Hadley Circulation, indicate that the models closer to the satellite observations tend to have equilibrium climate sensitivity higher than the multimodel mean.", "publicationTitle": "Journal of Geophysical Research: Atmospheres", "publisher": "", "place": "", "date": "May 27, 2014", "volume": "119", "issue": "10", "section": "", "partNumber": "", "partTitle": "", "pages": "2014JD021642", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JGR-Atmos", "DOI": "10.1002/2014JD021642", "citationKey": "suWeakeningStrengtheningStructures2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/2014JD021642/abstract", "accessDate": "2014-09-08T21:31:39Z", "PMID": "", "PMCID": "", "ISSN": "2169-8996", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2014. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "1620 Climate dynamics", "type": 1 }, { "tag": "3305 Climate change and variability", "type": 1 }, { "tag": "3310 Clouds and cloud feedbacks", "type": 1 }, { "tag": "3319 General circulation", "type": 1 }, { "tag": "3337 Global climate models", "type": 1 }, { "tag": "Climate sensitivity", "type": 1 }, { "tag": "cloud feedback", "type": 1 }, { "tag": "global warming", "type": 1 }, { "tag": "model performance metrics", "type": 1 }, { "tag": "satellite observations", "type": 1 }, { "tag": "the Hadley Circulation", "type": 1 } ], "collections": [ "SGZBBXXZ" ], "relations": { "owl:sameAs": "http://zotero.org/groups/285990/items/S6FCVQQ6" }, "dateAdded": "2014-09-09T21:00:34Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "5G2ZHV8S", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/5G2ZHV8S", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/5G2ZHV8S", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Zhao", "parsedDate": "2013-11-13", "numChildren": 0 }, "data": { "key": "5G2ZHV8S", "version": 98, "itemType": "journalArticle", "title": "An Investigation of the Connections among Convection, Clouds, and Climate Sensitivity in a Global Climate Model", "creators": [ { "creatorType": "author", "firstName": "Ming", "lastName": "Zhao" } ], "abstractNote": "AbstractThis study explores connections between process-level modeling of convection and global climate model (GCM) simulated clouds and cloud feedback to global warming through a set of perturbed-physics and perturbed sea surface temperature experiments. A bulk diagnostic approach is constructed, and a set of variables is derived and demonstrated to be useful in understanding the simulated relationship. In particular, a novel bulk quantity, the convective precipitation efficiency or equivalently the convective detrainment efficiency, is proposed as a simple measure of the aggregated properties of parameterized convection important to the GCM simulated clouds. As the convective precipitation efficiency increases in the perturbed-physics experiments, both liquid and ice water path decrease, with low and middle cloud fractions diminishing at a faster rate than high cloud fractions. This asymmetry results in a large sensitivity of top-of-atmosphere net cloud radiative forcing to changes in convective precipitation efficiency in this limited set of models.For global warming experiments, intermodel variations in the response of cloud condensate, low cloud fraction, and total cloud radiative forcing are well explained by model variations in response to total precipitation (or detrainment) efficiency. Despite significant variability, all of the perturbed-physics models produce a sizable increase in precipitation efficiency to warming. A substantial fraction of the increase is due to its convective component, which depends on the parameterization of cumulus mixing and convective microphysical processes. The increase in convective precipitation efficiency and associated change in convective cloud height distribution owing to warming explains the increased cloud feedback and climate sensitivity in recently developed Geophysical Fluid Dynamics Laboratory GCMs. The results imply that a cumulus scheme using fractional removal of condensate for precipitation and inverse calculation of the entrainment rate tends to produce a lower climate sensitivity than a scheme using threshold removal for precipitation and the entrainment rate formulated inversely dependent on convective depth.", "publicationTitle": "Journal of Climate", "publisher": "", "place": "", "date": "November 13, 2013", "volume": "27", "issue": "5", "section": "", "partNumber": "", "partTitle": "", "pages": "1845-1862", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JClim", "DOI": "10.1175/JCLI-D-13-00145.1", "citationKey": "zhaoInvestigationConnectionsConvection2013", "url": "http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00145.1", "accessDate": "2014-09-08T23:58:23Z", "PMID": "", "PMCID": "", "ISSN": "0894-8755", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "journals.ametsoc.org (Atypon)", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Climate change", "type": 1 }, { "tag": "Climate models", "type": 1 }, { "tag": "Climate sensitivity", "type": 1 }, { "tag": "Clouds", "type": 1 }, { "tag": "Convective parameterization", "type": 1 }, { "tag": "Feedback", "type": 1 } ], "collections": [ "NPC52HP5" ], "relations": { "owl:sameAs": "http://zotero.org/groups/285990/items/7UMUU93I" }, "dateAdded": "2014-09-10T02:31:05Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "ECDDE7ZI", "version": 98, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/ECDDE7ZI", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/ECDDE7ZI", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Peters et al.", "parsedDate": "2014-05-09", "numChildren": 0 }, "data": { "key": "ECDDE7ZI", "version": 98, "itemType": "journalArticle", "title": "Processes limiting the emergence of detectable aerosol indirect effects on tropical warm clouds in global aerosol-climate model and satellite data", "creators": [ { "creatorType": "author", "firstName": "Karsten", "lastName": "Peters" }, { "creatorType": "author", "firstName": "Johannes", "lastName": "Quaas" }, { "creatorType": "author", "firstName": "Philip", "lastName": "Stier" }, { "creatorType": "author", "firstName": "Hartmut", "lastName": "Graßl" } ], "abstractNote": "", "publicationTitle": "Tellus B", "publisher": "", "place": "", "date": "2014-5-9", "volume": "66", "issue": "0", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "TellusB", "DOI": "10.3402/tellusb.v66.24054", "citationKey": "petersProcessesLimitingEmergence2014", "url": "http://www.tellusb.net/index.php/tellusb/article/view/24054", "accessDate": "2014-09-09T21:11:12Z", "PMID": "", "PMCID": "", "ISSN": "1600-0889, 0280-6509", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "CrossRef", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-09T21:11:12Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "KZ4ITM5P", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/KZ4ITM5P", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/KZ4ITM5P", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Brueck et al.", "parsedDate": "2014", "numChildren": 2 }, "data": { "key": "KZ4ITM5P", "version": 97, "itemType": "journalArticle", "title": "On the seasonal and synoptic time scale variability of the North Atlantic trades and its low-level clouds", "creators": [ { "creatorType": "author", "firstName": "Matthias", "lastName": "Brueck" }, { "creatorType": "author", "firstName": "Louise", "lastName": "Nuijens" }, { "creatorType": "author", "firstName": "Bjorn", "lastName": "Stevens" } ], "abstractNote": "The large-scale meteorological environment in the North Atlantic trades and its influence on low-level cloudiness (CClow) is explored. 12 years of ERA-Interim and MODIS satellite observations and 2 years of ground-based measurements at the Barbados Cloud Observatory are used. Despite a strong seasonal contrast in the large-scale meteorology, the seasonality in CClow is small with a mean value of 30%, except for a minimum of 20% in September - November. Wind speed and temperature advection play a major role controlling variations in monthly mean CClow, through their co-variability with wind direction and large-scale vertical motion (ω). Seasonal CClow variations appear to correlate mostly with wind speed and temperature advection, which covary with wind direction and lower tropospheric stability (LTS). In the dry season increased advection of cold and dry air at strong northerly winds presumably lead to larger surface evaporation, which allows cumulus convection to effectively moisten the upper cloud layer and form stratiform-like layers just below the inversion, leading to higher CClow. Within the dry or wet regime an increase of mean ω with an associated decrease in relative humidity, tend to decrease CClow. However across seasons this relationship is diminished by the effect of ω on LTS. On synoptic time scales the covariability of winds, advection and LTS breaks down, reducing their influence on CClow. The factors that best explain CClow variations on those time scales are relative humidity, wind speed and ω700 hPa. The lack of a single strong predictor emphasizes that the combined effect of different parameters is necessary to explain variations in CClow.", "publicationTitle": "", "publisher": "", "place": "", "date": "2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "PrePress", "DOI": "", "citationKey": "brueckSeasonalSynopticTime2014", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [ "6S9327I6" ], "relations": {}, "dateAdded": "2014-10-09T17:22:36Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "ZA65B7SF", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/ZA65B7SF", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/ZA65B7SF", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Meehl et al.", "parsedDate": "2014-10", "numChildren": 2 }, "data": { "key": "ZA65B7SF", "version": 97, "itemType": "journalArticle", "title": "Climate model simulations of the observed early-2000s hiatus of global warming", "creators": [ { "creatorType": "author", "firstName": "Gerald A.", "lastName": "Meehl" }, { "creatorType": "author", "firstName": "Haiyan", "lastName": "Teng" }, { "creatorType": "author", "firstName": "Julie M.", "lastName": "Arblaster" } ], "abstractNote": "The slowdown in the rate of global warming in the early 2000s is not evident in the multi-model ensemble average of traditional climate change projection simulations. However, a number of individual ensemble members from that set of models successfully simulate the early-2000s hiatus when naturally-occurring climate variability involving the Interdecadal Pacific Oscillation (IPO) coincided, by chance, with the observed negative phase of the IPO that contributed to the early-2000s hiatus. If the recent methodology of initialized decadal climate prediction could have been applied in the mid-1990s using the Coupled Model Intercomparison Project Phase 5 multi-models, both the negative phase of the IPO in the early 2000s as well as the hiatus could have been simulated, with the multi-model average performing better than most of the individual models. The loss of predictive skill for six initial years before the mid-1990s points to the need for consistent hindcast skill to establish reliability of an operational decadal climate prediction system.", "publicationTitle": "Nature Climate Change", "publisher": "", "place": "", "date": "October 2014", "volume": "4", "issue": "10", "section": "", "partNumber": "", "partTitle": "", "pages": "898-902", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Nature Clim. Change", "DOI": "10.1038/nclimate2357", "citationKey": "meehlClimateModelSimulations2014", "url": "http://www.nature.com/nclimate/journal/v4/n10/full/nclimate2357.html", "accessDate": "2014-10-09T17:26:22Z", "PMID": "", "PMCID": "", "ISSN": "1758-678X", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "www.nature.com", "callNumber": "", "rights": "© 2014 Nature Publishing Group", "extra": "", "tags": [], "collections": [ "9MVRCTXV", "ABEVT668" ], "relations": { "dc:replaces": "http://zotero.org/groups/286513/items/R8EEVR4V" }, "dateAdded": "2014-10-09T17:26:22Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "AJER25IF", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/AJER25IF", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/AJER25IF", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Wang et al.", "parsedDate": "2012-08-16", "numChildren": 1 }, "data": { "key": "AJER25IF", "version": 97, "itemType": "journalArticle", "title": "Constraining cloud lifetime effects of aerosols using A-Train satellite observations", "creators": [ { "creatorType": "author", "firstName": "Minghuai", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Steven", "lastName": "Ghan" }, { "creatorType": "author", "firstName": "Xiaohong", "lastName": "Liu" }, { "creatorType": "author", "firstName": "Tristan S.", "lastName": "L'Ecuyer" }, { "creatorType": "author", "firstName": "Kai", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Hugh", "lastName": "Morrison" }, { "creatorType": "author", "firstName": "Mikhail", "lastName": "Ovchinnikov" }, { "creatorType": "author", "firstName": "Richard", "lastName": "Easter" }, { "creatorType": "author", "firstName": "Roger", "lastName": "Marchand" }, { "creatorType": "author", "firstName": "Duli", "lastName": "Chand" }, { "creatorType": "author", "firstName": "Yun", "lastName": "Qian" }, { "creatorType": "author", "firstName": "Joyce E.", "lastName": "Penner" } ], "abstractNote": "Aerosol indirect effects have remained the largest uncertainty in estimates of the radiative forcing of past and future climate change. Observational constraints on cloud lifetime effects are particularly challenging since it is difficult to separate aerosol effects from meteorological influences. Here we use three global climate models, including a multi-scale aerosol-climate model PNNL-MMF, to show that the dependence of the probability of precipitation on aerosol loading, termed the precipitation frequency susceptibility (Spop), is a good measure of the liquid water path response to aerosol perturbation (λ), as both Spop and λ strongly depend on the magnitude of autoconversion, a model representation of precipitation formation via collisions among cloud droplets. This provides a method to use satellite observations to constrain cloud lifetime effects in global climate models. Spopin marine clouds estimated from CloudSat, MODIS and AMSR-E observations is substantially lower than that from global climate models and suggests a liquid water path increase of less than 5% from doubled cloud condensation nuclei concentrations. This implies a substantially smaller impact on shortwave cloud radiative forcing over ocean due to aerosol indirect effects than simulated by current global climate models (a reduction by one-third for one of the conventional aerosol-climate models). Further work is needed to quantify the uncertainties in satellite-derived estimates ofSpop and to examine Spopin high-resolution models.", "publicationTitle": "Geophysical Research Letters", "publisher": "", "place": "", "date": "August 16, 2012", "volume": "39", "issue": "15", "section": "", "partNumber": "", "partTitle": "", "pages": "L15709", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "GRL", "DOI": "10.1029/2012GL052204", "citationKey": "wangConstrainingCloudLifetime2012", "url": "http://onlinelibrary.wiley.com/doi/10.1029/2012GL052204/abstract", "accessDate": "2014-09-23T19:31:23Z", "PMID": "", "PMCID": "", "ISSN": "1944-8007", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2012. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "0305 Aerosols and particles", "type": 1 }, { "tag": "0320 Cloud physics and chemistry", "type": 1 }, { "tag": "0321 Cloud/radiation interaction", "type": 1 }, { "tag": "0345 Pollution: urban and regional", "type": 1 }, { "tag": "0360 Radiation: transmission and scattering", "type": 1 }, { "tag": "MMF", "type": 1 }, { "tag": "cloud lifetime effects", "type": 1 }, { "tag": "rain frequency susceptibility", "type": 1 }, { "tag": "satellite constraint", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-23T19:31:23Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "CENR5FAE", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/CENR5FAE", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/CENR5FAE", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Park", "parsedDate": "2014-08-08", "numChildren": 0 }, "data": { "key": "CENR5FAE", "version": 97, "itemType": "journalArticle", "title": "A Unified Convection Scheme, UNICON. Part II. Simulation", "creators": [ { "creatorType": "author", "firstName": "Sungsu", "lastName": "Park" } ], "abstractNote": "AbstractA Unified Convection Scheme (UNICON) is implemented into the Community Atmosphere Model version 5 (CAM5) and tested in single-column and global simulations forced by observed sea surface temperature. Compared to CAM5, UNICON substantially improves the single-column simulations of stratocumulus-to-cumulus transition, and shallow and deep convection cases. The global performance of UNICON is similar to CAM5 with a relative spatio-temporal root-mean-square error (RMSE) of 0.777 (0.755 in CAM5) against the earlier version of the model (CCSM3.5). The notable improvements in the UNICON-simulated climatologies over CAM5 are • seasonal precipitation patterns (i.e. monsoon) over the western Pacific and South Asia, • reduced biases of cloud radiative forcing in the tropical deep convection regions, • aerosol optical depth in the tropical and sub-tropical regions, and • cumulus fraction and in-cumulus condensate. One notable degradation is that UNICON simulates warmer near-surface air temperature over the U.S. during summer.In addition to the climatology, UNICON significantly improves the simulation of the diurnal cycle of precipitation and the Madden-Julian Oscillation (MJO). The surface precipitation simulated by UNICON is a maximum in the late afternoon (early afternoon in CAM5) over the summer continents and in the early morning (pre-dawn in CAM5) over the ocean with a fairly realistic amplitude of the diurnal cycle. Sensitivity simulations indicate that the key for successful MJO simulation in UNICON is a seamless parameterization of the updraft plume dilution rate as convection evolves from shallow to deep convection. The mesoscale perturbation of the vertical velocity and the thermodynamic scalars of convective updrafts is an additional requirement for simulating the observed diurnal cycle of precipitation.", "publicationTitle": "Journal of the Atmospheric Sciences", "publisher": "", "place": "", "date": "August 8, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JAS", "DOI": "10.1175/JAS-D-13-0234.1", "citationKey": "parkUnifiedConvectionScheme2014", "url": "http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-13-0234.1", "accessDate": "2014-09-11T17:56:26Z", "PMID": "", "PMCID": "", "ISSN": "0022-4928", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "journals.ametsoc.org (Atypon)", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:56:26Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "FIB5C48T", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/FIB5C48T", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/FIB5C48T", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Zhang et al.", "parsedDate": "2014-09-01", "numChildren": 0 }, "data": { "key": "FIB5C48T", "version": 97, "itemType": "journalArticle", "title": "Investigating ice nucleation in cirrus clouds with an aerosol-enabled multiscale modeling framework", "creators": [ { "creatorType": "author", "firstName": "Chengzhu", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Minghuai", "lastName": "Wang" }, { "creatorType": "author", "firstName": "Hugh", "lastName": "Morrison" }, { "creatorType": "author", "firstName": "Richard C. J.", "lastName": "Somerville" }, { "creatorType": "author", "firstName": "Kai", "lastName": "Zhang" }, { "creatorType": "author", "firstName": "Xiaohong", "lastName": "Liu" }, { "creatorType": "author", "firstName": "Jui-Lin F.", "lastName": "Li" } ], "abstractNote": "In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following the homogeneous nucleation threshold. The MMF model predicts a higher frequency of midlatitude supersaturation in the Southern Hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to simulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation scheme and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 μm for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement with the satellite-retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.", "publicationTitle": "Journal of Advances in Modeling Earth Systems", "publisher": "", "place": "", "date": "September 1, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "n/a-n/a", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JAMES", "DOI": "10.1002/2014MS000343", "citationKey": "zhangInvestigatingIceNucleation2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/2014MS000343/abstract", "accessDate": "2014-09-11T17:55:48Z", "PMID": "", "PMCID": "", "ISSN": "1942-2466", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2014. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "0305 Aerosols and particles", "type": 1 }, { "tag": "1610 Atmosphere", "type": 1 }, { "tag": "1863 Snow and ice", "type": 1 }, { "tag": "3311 Clouds and aerosols", "type": 1 }, { "tag": "Cirrus Simulation", "type": 1 }, { "tag": "Ice Nucleation", "type": 1 }, { "tag": "Super-parameterization", "type": 1 }, { "tag": "aerosol cloud interaction", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:55:48Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "24CVJMQU", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/24CVJMQU", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/24CVJMQU", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Tomassini et al.", "parsedDate": "2014-09-01", "numChildren": 0 }, "data": { "key": "24CVJMQU", "version": 97, "itemType": "journalArticle", "title": "On the connection between tropical circulation, convective mixing, and climate sensitivity", "creators": [ { "creatorType": "author", "firstName": "L.", "lastName": "Tomassini" }, { "creatorType": "author", "firstName": "A.", "lastName": "Voigt" }, { "creatorType": "author", "firstName": "B.", "lastName": "Stevens" } ], "abstractNote": "The connection between the large-scale tropical circulation of the atmosphere, convective mixing, and climate sensitivity is explored in a wide range of climates through a perturbed-parameter ensemble of a comprehensive Earth-System Model. Four parameters related to the representation of atmospheric moist convection are found to dominate the response of the model. Their values govern the strength of the tropical circulation, the surface temperature, atmospheric humidity, and the strength of the tropical overturning circulation, largely through their influence on the atmospheric stability. The same convective parameters, albeit in different combinations, also have a strong influence on the equilibrium climate sensitivity of the model, which ranges from a little over 3 ∘ C to more than 10 ∘ C. The importance of the most poorly represented processes in determining important aspects of the behavior of the model argues for the need to move beyond statistical approaches to estimating climate sensitivity and focusing on the development of a better understanding and representation of convective mixing, particularly in the tropics.", "publicationTitle": "Quarterly Journal of the Royal Meteorological Society", "publisher": "", "place": "", "date": "September 1, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "n/a-n/a", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "QJ-RMS", "DOI": "10.1002/qj.2450", "citationKey": "tomassiniConnectionTropicalCirculation2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/qj.2450/abstract", "accessDate": "2014-09-11T17:54:53Z", "PMID": "", "PMCID": "", "ISSN": "1477-870X", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "This article is protected by copyright. All rights reserved.", "extra": "", "tags": [ { "tag": "Climate sensitivity", "type": 1 }, { "tag": "convection parameterization", "type": 1 }, { "tag": "convective mixing", "type": 1 }, { "tag": "tropical circulation", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:54:53Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "8KH5DWQG", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/8KH5DWQG", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/8KH5DWQG", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Webb et al.", "parsedDate": "2014-07-24", "numChildren": 0 }, "data": { "key": "8KH5DWQG", "version": 97, "itemType": "journalArticle", "title": "The diurnal cycle of marine cloud feedback in climate models", "creators": [ { "creatorType": "author", "firstName": "Mark J.", "lastName": "Webb" }, { "creatorType": "author", "firstName": "Adrian P.", "lastName": "Lock" }, { "creatorType": "author", "firstName": "Alejandro", "lastName": "Bodas-Salcedo" }, { "creatorType": "author", "firstName": "Sandrine", "lastName": "Bony" }, { "creatorType": "author", "firstName": "Jason N. S.", "lastName": "Cole" }, { "creatorType": "author", "firstName": "Tsuyoshi", "lastName": "Koshiro" }, { "creatorType": "author", "firstName": "Hideaki", "lastName": "Kawai" }, { "creatorType": "author", "firstName": "Carlo", "lastName": "Lacagnina" }, { "creatorType": "author", "firstName": "Frank M.", "lastName": "Selten" }, { "creatorType": "author", "firstName": "Romain", "lastName": "Roehrig" }, { "creatorType": "author", "firstName": "Bjorn", "lastName": "Stevens" } ], "abstractNote": "We examine the diurnal cycle of marine cloud feedback using high frequency outputs in CFMIP-2 idealised uniform +4 K SST perturbation experiments from seven CMIP5 models. Most of the inter-model spread in the diurnal mean marine shortwave cloud feedback can be explained by low cloud responses, although these do not explain the model responses at the neutral/weakly negative end of the feedback range, where changes in mid and high level cloud properties are more important. All of the models show reductions in marine low cloud fraction in the warmer climate, and these are in almost all cases largest in the mornings when more cloud is present in the control simulations. This results in shortwave cloud feedbacks being slightly stronger and having the largest inter-model spread at this time of day. The diurnal amplitudes of the responses of marine cloud properties to the warming climate are however small compared to the inter-model differences in their diurnally meaned responses. This indicates that the diurnal cycle of cloud feedback is not strongly relevant to understanding inter-model spread in overall cloud feedback and climate sensitivity. A number of unusual behaviours in individual models are highlighted for future investigation.", "publicationTitle": "Climate Dynamics", "publisher": "", "place": "", "date": "2014/07/24", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "1-18", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "ClimDyn", "DOI": "10.1007/s00382-014-2234-1", "citationKey": "webbDiurnalCycleMarine2014", "url": "http://link.springer.com/article/10.1007/s00382-014-2234-1", "accessDate": "2014-09-11T17:54:40Z", "PMID": "", "PMCID": "", "ISSN": "0930-7575, 1432-0894", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "link.springer.com", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Climate change", "type": 1 }, { "tag": "Climatology", "type": 1 }, { "tag": "Diurnal cycle", "type": 1 }, { "tag": "Geophysics/Geodesy", "type": 1 }, { "tag": "Oceanography", "type": 1 }, { "tag": "cloud feedback", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:54:40Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "PMJZRMTW", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/PMJZRMTW", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/PMJZRMTW", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Koshiro and Shiotani", "parsedDate": "2014", "numChildren": 0 }, "data": { "key": "PMJZRMTW", "version": 97, "itemType": "journalArticle", "title": "Relationship between Low Stratiform Cloud Amount and Estimated Inversion Strength in the Lower Troposphere over the Global Ocean in Terms of Cloud Types", "creators": [ { "creatorType": "author", "firstName": "Tsuyoshi", "lastName": "Koshiro" }, { "creatorType": "author", "firstName": "Masato", "lastName": "Shiotani" } ], "abstractNote": "Low stratiform clouds (LSCs) are of three different types: stratocumulus (Sc), stratus (St), and sky-obscuring fog (FOG). Ship-based cloud observations (September 1957-August 2002) and air-temperature and sea-level pressure data obtained from the ERA-40 reanalysis are used to investigate the seasonal relationships between the amounts of these LSC types and the estimated inversion strength (EIS) over the global ocean. Although it is known that a single linear relationship applies to the variations in the LSC amount as the sum of those of the LSC types and EIS, two relationships with different sensitivities are found between each LSC-type amount and EIS. The boundary lies at a sea surface temperature (SST) of approximately 16°C. The Sc amount is strongly correlated with EIS in the warm SST regime, whereas no correlation can be observed between them in the cold SST regime. In contrast, although FOG rarely occurs in the warm SST regime, its amount increases with EIS in the cold SST regime. The St amount increases with EIS in both regimes, with higher sensitivity in the cold SST regime. Examination of vertical layers contributing to EIS reveals that an increase in the inferred inversion strength between 850- and 925-hPa levels corresponds to that in the Sc amount in the warm SST regime. In the cold SST regime, as EIS increases, relatively high values of inferred inversion strength between 700- and 850-hPa levels change to a rapid increase in that between 925-hPa level and the surface, which coincides with the transition from Sc to FOG. Temperature advection implied by the air-sea temperature difference provides favorable conditions to the different variations in the two regimes: general occurrence of cold advection in the warm SST regime and cold-to-warm transition of advection in the cold SST regime.", "publicationTitle": "Journal of the Meteorological Society of Japan. Ser. II", "publisher": "", "place": "", "date": "2014", "volume": "92", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "107-120", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JMetSoc-Japan", "DOI": "10.2151/jmsj.2014-107", "citationKey": "koshiroRelationshipLowStratiform2014", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "J-Stage", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "air-sea temperature difference", "type": 1 }, { "tag": "inversion strength", "type": 1 }, { "tag": "low stratiform cloud", "type": 1 }, { "tag": "sea surface temperature", "type": 1 }, { "tag": "temperature advection", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-12T02:19:15Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "VGJBNGZV", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/VGJBNGZV", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/VGJBNGZV", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Vallis et al.", "parsedDate": "2014-09-01", "numChildren": 0 }, "data": { "key": "VGJBNGZV", "version": 97, "itemType": "journalArticle", "title": "Response of the Large-Scale Structure of the Atmosphere to Global Warming", "creators": [ { "creatorType": "author", "firstName": "Geoffrey K.", "lastName": "Vallis" }, { "creatorType": "author", "firstName": "Pablo", "lastName": "Zurita-Gotor" }, { "creatorType": "author", "firstName": "Cameron", "lastName": "Cairns" }, { "creatorType": "author", "firstName": "Joseph", "lastName": "Kidston" } ], "abstractNote": "This paper discusses the possible response of the large-scale atmospheric structure to a warmer climate. Using integrations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) in conjunction with physical arguments, we try to identify what changes are likely to be robust and what the underlying mechanisms might be. We focus on the large-scale zonally-averaged circulation, in particular on height of the tropopause, the strength and position of the surface westerlies and the strength and extent of the Hadley Cell. We present analytic arguments and numerical calculations that suggest that under global warming the height of the tropopause will increase in both the transient response and final equilibrium state, and an increase is clearly found in all the comprehensive models in CMIP5. Upper stratospheric cooling is also found in the comprehensive models, and this too can be explained by a radiative argument. Regarding the circulation, most models show a slight expansion and weakening of the Hadley Cell, depending on season and hemisphere. The expansion is small and largely confined to winter but with some expansion in Southern Hemisphere summer. The weakening occurs principally in Northern Hemisphere but the intermodel scatter is large. There is also a general polewards shift in surface westerlies, but the changes are small and again are little larger than the inter-model variability in the change. This shift is positively correlated with the Hadley Cell expansion to a degree that depends somewhat on the metric chosen for the latter. There is a robust strengthening in the Southern Hemisphere surface winds across seasons. In the Northern Hemisphere there is a slight strengthening in the westerlies in most models in winter but a consistent weakening of the westerlies in summer. We present various physical arguments concerning these circulation changes but none that are both demonstrably correct and that account for the model results. We conclude that the above-mentioned large-scale thermodynamic/radiative changes in the large-scale atmospheric structure are generally robust, in the sense of being both well understood and consistently reproduced by comprehensive models. In that sense the dynamical changes are less robust given the current state of knowledge and simulation, although one cannot conclude that they are, in principle, unknowable or less predictable.", "publicationTitle": "Quarterly Journal of the Royal Meteorological Society", "publisher": "", "place": "", "date": "September 1, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "n/a-n/a", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "QJ-RMS", "DOI": "10.1002/qj.2456", "citationKey": "vallisResponseLargeScaleStructure2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/qj.2456/abstract", "accessDate": "2014-09-11T17:55:25Z", "PMID": "", "PMCID": "", "ISSN": "1477-870X", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "This article is protected by copyright. All rights reserved.", "extra": "", "tags": [ { "tag": "Climate change", "type": 1 }, { "tag": "General Circulation", "type": 1 }, { "tag": "Westerlies", "type": 1 }, { "tag": "global warming", "type": 1 } ], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:55:25Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "QSNSBUK5", "version": 97, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/QSNSBUK5", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/QSNSBUK5", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Merlis et al.", "parsedDate": "2014-07-31", "numChildren": 0 }, "data": { "key": "QSNSBUK5", "version": 97, "itemType": "journalArticle", "title": "Constraining transient climate sensitivity using coupled climate model simulations of volcanic eruptions", "creators": [ { "creatorType": "author", "firstName": "Timothy M.", "lastName": "Merlis" }, { "creatorType": "author", "firstName": "Isaac M.", "lastName": "Held" }, { "creatorType": "author", "firstName": "Georgiy L.", "lastName": "Stenchikov" }, { "creatorType": "author", "firstName": "Fanrong", "lastName": "Zeng" }, { "creatorType": "author", "firstName": "Larry W.", "lastName": "Horowitz" } ], "abstractNote": "AbstractCoupled climate model simulations of volcanic eruptions and abrupt changes in CO2 concentration are compared in multiple realizations of Geophysical Fluid Dynamics Laboratory’s (GFDL) CM2.1. The change in global-mean surface temperature (GMST) is analyzed to determine whether a fast component of the climate sensitivity of relevance to the transient climate response (TCR, defined with the 1% yr−1 CO2-increase scenario) can be estimated from shorter-timescale climate changes. The fast component of the climate sensitivity estimated from the response of the climate model to volcanic forcing is similar to that of the simulations forced by abrupt CO2 changes, but is 5–15% smaller than the TCR. In addition, the partition between the top-of-atmosphere radiative restoring and ocean heat uptake is similar across radiative forcing agents. The possible asymmetry between warming and cooling climate perturbations, which may affect the utility of volcanic eruptions for estimating the TCR, is assessed by comparing simulations of abrupt CO2 doubling to abrupt CO2 halving. There is slightly less (~5%) GMST change in 0.5 × CO2 simulations than in 2 × CO2 simulations on the short (~10-yr) timescales relevant to the fast component of the volcanic signal. However, inferring the TCR from volcanic eruptions is more sensitive to uncertainties from internal climate variability and the estimation procedure.The response of the GMST to volcanic eruptions is similar in GFDL’s CM2.1 and CM3, even though the latter has a higher TCR associated with a multidecadal timescale in its response. This is consistent with the expectation that the fast component of the climate sensitivity inferred from volcanic eruptions is a lower bound for the TCR.", "publicationTitle": "Journal of Climate", "publisher": "", "place": "", "date": "July 31, 2014", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "JClim", "DOI": "10.1175/JCLI-D-14-00214.1", "citationKey": "merlisConstrainingTransientClimate2014", "url": "http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00214.1", "accessDate": "2014-09-11T17:55:02Z", "PMID": "", "PMCID": "", "ISSN": "0894-8755", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "journals.ametsoc.org (Atypon)", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [ "ABEVT668" ], "relations": {}, "dateAdded": "2014-09-11T17:55:02Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "UCBXXAQ6", "version": 96, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/UCBXXAQ6", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/UCBXXAQ6", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Gregory and Andrews", "parsedDate": "2016-04-28", "numChildren": 3 }, "data": { "key": "UCBXXAQ6", "version": 96, "itemType": "journalArticle", "title": "Variation in climate sensitivity and feedback parameters during the historical period", "creators": [ { "creatorType": "author", "firstName": "J. M.", "lastName": "Gregory" }, { "creatorType": "author", "firstName": "T.", "lastName": "Andrews" } ], "abstractNote": "We investigate the climate feedback parameter α (W m−2 K−1) during the historical period (since 1871) in experiments using the HadGEM2 and HadCM3 atmosphere general circulation models (AGCMs) with constant preindustrial atmospheric composition and time-dependent observational sea surface temperature (SST) and sea ice boundary conditions. In both AGCMs, for the historical period as a whole, the effective climate sensitivity is ∼2 K (α≃1.7 W m−2 K−1), and α shows substantial decadal variation caused by the patterns of SST change. Both models agree with the AGCMs of the latest Coupled Model Intercomparison Project in showing a considerably smaller effective climate sensitivity of ∼1.5 K (α = 2.3 ± 0.7 W m−2 K−1), given the time-dependent changes in sea surface conditions observed during 1979–2008, than the corresponding coupled atmosphere-ocean general circulation models (AOGCMs) give under constant quadrupled CO2 concentration. These findings help to relieve the apparent contradiction between the larger values of effective climate sensitivity diagnosed from AOGCMs and the smaller values inferred from historical climate change.", "publicationTitle": "Geophysical Research Letters", "publisher": "", "place": "", "date": "April 28, 2016", "volume": "43", "issue": "8", "section": "", "partNumber": "", "partTitle": "", "pages": "2016GL068406", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Geophys. Res. Lett.", "DOI": "10.1002/2016GL068406", "citationKey": "gregoryVariationClimateSensitivity2016", "url": "http://onlinelibrary.wiley.com/doi/10.1002/2016GL068406/abstract", "accessDate": "2016-11-28T19:36:02Z", "PMID": "", "PMCID": "", "ISSN": "1944-8007", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "1620 Climate dynamics" }, { "tag": "3305 Climate change and variability" }, { "tag": "3310 Clouds and cloud feedbacks" }, { "tag": "3337 Global climate models" }, { "tag": "AGCM" }, { "tag": "AMIP" }, { "tag": "Climate sensitivity" }, { "tag": "climate feedback" }, { "tag": "climate variability" }, { "tag": "radiative forcing" } ], "collections": [ "RVFVNNQJ" ], "relations": { "dc:replaces": "http://zotero.org/groups/286513/items/5KJ3MIDD" }, "dateAdded": "2016-11-28T19:36:02Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "3Z76MXJU", "version": 96, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/3Z76MXJU", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/3Z76MXJU", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1363678, "username": "jstemmler", "name": "Jayson Stemmler", "links": { "alternate": { "href": "https://www.zotero.org/jstemmler", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Zhou et al.", "parsedDate": "2016-10-31", "numChildren": 2 }, "data": { "key": "3Z76MXJU", "version": 96, "itemType": "journalArticle", "title": "Impact of decadal cloud variations on the Earth/'s energy budget", "creators": [ { "creatorType": "author", "firstName": "Chen", "lastName": "Zhou" }, { "creatorType": "author", "firstName": "Mark D.", "lastName": "Zelinka" }, { "creatorType": "author", "firstName": "Stephen A.", "lastName": "Klein" } ], "abstractNote": "Feedbacks of clouds on climate change strongly influence the magnitude of global warming. Cloud feedbacks, in turn, depend on the spatial patterns of surface warming, which vary on decadal timescales. Therefore, the magnitude of the decadal cloud feedback could deviate from the long-term cloud feedback. Here we present climate model simulations to show that the global mean cloud feedback in response to decadal temperature fluctuations varies dramatically due to time variations in the spatial pattern of sea surface temperature. We find that cloud anomalies associated with these patterns significantly modify the Earth’s energy budget. Specifically, the decadal cloud feedback between the 1980s and 2000s is substantially more negative than the long-term cloud feedback. This is a result of cooling in tropical regions where air descends, relative to warming in tropical ascent regions, which strengthens low-level atmospheric stability. Under these conditions, low-level cloud cover and its reflection of solar radiation increase, despite an increase in global mean surface temperature. These results suggest that sea surface temperature pattern-induced low cloud anomalies could have contributed to the period of reduced warming between 1998 and 2013, and offer a physical explanation of why climate sensitivities estimated from recently observed trends are probably biased low.", "publicationTitle": "Nature Geoscience", "publisher": "", "place": "", "date": "October 31, 2016", "volume": "advance online publication", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Nature Geosci", "DOI": "10.1038/ngeo2828", "citationKey": "zhouImpactDecadalCloud2016", "url": "http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2828.html", "accessDate": "2016-11-28T18:20:48Z", "PMID": "", "PMCID": "", "ISSN": "1752-0894", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "www.nature.com", "callNumber": "", "rights": "© 2016 Nature Publishing Group", "extra": "", "tags": [ { "tag": "Atmospheric science", "type": 1 }, { "tag": "Attribution", "type": 1 } ], "collections": [ "RVFVNNQJ" ], "relations": {}, "dateAdded": "2016-11-28T18:20:48Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "6PD9MM4D", "version": 96, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/6PD9MM4D", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/6PD9MM4D", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Simpson et al.", "parsedDate": "2014-07-27", "numChildren": 1 }, "data": { "key": "6PD9MM4D", "version": 96, "itemType": "journalArticle", "title": "Dimethyl sulfide: Less important than long-range transport as a source of sulfate to the remote tropical Pacific marine boundary layer", "creators": [ { "creatorType": "author", "firstName": "Rebecca M. C.", "lastName": "Simpson" }, { "creatorType": "author", "firstName": "Steven G.", "lastName": "Howell" }, { "creatorType": "author", "firstName": "Byron W.", "lastName": "Blomquist" }, { "creatorType": "author", "firstName": "Antony D.", "lastName": "Clarke" }, { "creatorType": "author", "firstName": "Barry J.", "lastName": "Huebert" } ], "abstractNote": "During the Pacific Atmospheric Sulfur Experiment (PASE), dimethyl sulfide (DMS) was not the principal source of non–sea salt sulfate (NSS) mass in the remote marine boundary layer (MBL), according to an Eulerian sulfur budget based on observations of chemical concentrations from the NCAR C-130 in relatively dry, subsiding regions of the tropical Pacific. Our three (DMS, SO2, and NSS) monthly-average budgets are mutually consistent. The PASE-average DMS emission was 3.0 ± 0.5μmol m−2 d−1 (our budget “units”). SO2 sources include DMS + OH (1.4 ± 0.4 units, assuming 75% of reacted DMS forms SO2) and entrainment from the free troposphere (FT) (0.8 ± 0.2 units). Clouds were the most important chemical reactors for SO2 (−1.0 ± 0.5 units). SO2 loss terms also include divergence (−0.9 ± 0.3 units), dry deposition (−0.5 ± 0.2 units), and OH + SO2 (−0.22 ± 0.05 units). The total SO2 loss balanced the SO2 source. We assume that no SO2 was lost to ozone oxidation on sea salt particles; we found negligible NSS on particles from 2.6 μm (the sea salt mass peak) to 10 μm diameter. Fine-particle NSS sources include in-cloud oxidation of SO2 by H2O2 (1.0 ± 0.5 units), OH + SO2 (0.19 ± 0.05 units), and entrainment (1.1 ± 0.3 units in clean conditions; twice that when continental pollution is present). NSS sources balance NSS loss to divergence. Only about one fourth of emitted DMS becomes NSS. FT entrainment supplied two thirds and DMS oxidation produced one third of MBL NSS, rather similar source terms.", "publicationTitle": "Journal of Geophysical Research: Atmospheres", "publisher": "", "place": "", "date": "July 27, 2014", "volume": "119", "issue": "14", "section": "", "partNumber": "", "partTitle": "", "pages": "9142-9167", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "J. Geophys. Res. Atmos.", "DOI": "10.1002/2014JD021643", "citationKey": "simpsonDimethylSulfideLess2014", "url": "http://onlinelibrary.wiley.com.offcampus.lib.washington.edu/doi/10.1002/2014JD021643/abstract", "accessDate": "2015-09-03T01:40:28Z", "PMID": "", "PMCID": "", "ISSN": "2169-8996", "archive": "", "archiveLocation": "", "shortTitle": "Dimethyl sulfide", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "0305 Aerosols and particles", "type": 1 }, { "tag": "0322 Constituent sources and sinks", "type": 1 }, { "tag": "3307 Boundary layer processes", "type": 1 }, { "tag": "4801 Aerosols", "type": 1 }, { "tag": "9355 Pacific Ocean", "type": 1 }, { "tag": "Entrainment", "type": 1 }, { "tag": "long-range transport, SO2 oxidation chemistry", "type": 1 }, { "tag": "marine boundary layer", "type": 1 }, { "tag": "sulfate aerosol", "type": 1 } ], "collections": [], "relations": {}, "dateAdded": "2015-09-03T01:40:28Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "25QZWX7U", "version": 96, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/25QZWX7U", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/25QZWX7U", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "numChildren": 1 }, "data": { "key": "25QZWX7U", "version": 96, "itemType": "webpage", "title": "Dimethyl sulfide: Less important than long-range transport as a source of sulfate to the remote tropical Pacific marine boundary layer - Simpson - 2014 - Journal of Geophysical Research: Atmospheres - Wiley Online Library", "creators": [], "abstractNote": "", "websiteTitle": "", "websiteType": "", "date": "", "publisher": "", "place": "", "DOI": "", "citationKey": "DimethylSulfideLess", "url": "http://onlinelibrary.wiley.com.offcampus.lib.washington.edu/doi/10.1002/2014JD021643/abstract", "accessDate": "2015-09-03T01:40:26Z", "shortTitle": "", "language": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2015-09-03T01:40:26Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "T6QR5MJB", "version": 96, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/T6QR5MJB", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/T6QR5MJB", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Logan et al.", "parsedDate": "2014", "numChildren": 1 }, "data": { "key": "T6QR5MJB", "version": 96, "itemType": "journalArticle", "title": "Aerosol properties and their influences on marine boundary layer cloud condensation nuclei at the ARM mobile facility over the Azores", "creators": [ { "creatorType": "author", "firstName": "Timothy", "lastName": "Logan" }, { "creatorType": "author", "firstName": "Baike", "lastName": "Xi" }, { "creatorType": "author", "firstName": "Xiquan", "lastName": "Dong" } ], "abstractNote": "A multiplatform data set from the Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (MBL) Graciosa, Azores, 2009–2010 field campaign was used to investigate how continental aerosols can influence MBL cloud condensation nuclei (CCN) number concentration (NCCN). The seasonal variations of aerosol properties have shown that the winter and early spring months had the highest mean surface wind speed (> 5 m s−1) and greatest contribution of sea salt to aerosol optical depth (AOD), while continental fine mode aerosols were the main contributors to AOD during the warm season months (May–September). Five aerosol events consisting of mineral dust, pollution, biomass smoke, and volcanic ash particles were selected as case studies using Atmospheric Radiation Measurement (ARM) mobile facility measurements. The aerosols in Case I were found to primarily consist of coarse mode, Saharan mineral dust. For Case II, the aerosols were also coarse mode but consisted of volcanic ash. Case III had fine mode biomass smoke and pollution aerosol influences while Cases IV and V consisted of mixtures of North American pollution and Saharan dust that was advected by an extratropical cyclone to the Azores. Cases I, IV, and V exhibited weak correlations between aerosol loading and NCCN due to mineral dust influences, while Cases II and III had a strong relationship with NCCN likely due to the sulfate content in the volcanic ash and pollution particles. The permanent Eastern North Atlantic ARM facility over the Azores will aid in a future long-term study of aerosol effects on NCCN.", "publicationTitle": "Journal of Geophysical Research: Atmospheres", "publisher": "", "place": "", "date": "2014", "volume": "119", "issue": "8", "section": "", "partNumber": "", "partTitle": "", "pages": "2013JD021288", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "J. Geophys. Res. Atmos.", "DOI": "10.1002/2013JD021288", "citationKey": "loganAerosolPropertiesTheir2014", "url": "http://onlinelibrary.wiley.com/doi/10.1002/2013JD021288/abstract", "accessDate": "2015-02-13T17:38:23Z", "PMID": "", "PMCID": "", "ISSN": "2169-8996", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "©2014. American Geophysical Union. All Rights Reserved.", "extra": "", "tags": [ { "tag": "0305 Aerosols and particles", "type": 1 }, { "tag": "0322 Constituent sources and sinks", "type": 1 }, { "tag": "0368 Troposphere: constituent transport and chemistry", "type": 1 }, { "tag": "3311 Clouds and aerosols", "type": 1 }, { "tag": "9325 Atlantic Ocean", "type": 1 }, { "tag": "aerosol classification", "type": 1 }, { "tag": "aerosol indirect effect", "type": 1 }, { "tag": "aerosol properties", "type": 1 }, { "tag": "marine boundary layer", "type": 1 } ], "collections": [ "GCIN6MCN" ], "relations": {}, "dateAdded": "2015-02-13T17:38:23Z", "dateModified": "2026-02-17T04:02:31Z" } }, { "key": "AVP7ICNQ", "version": 96, "library": { "type": "group", "id": 286513, "name": "UW Cloud Climate Reading Group", "links": { "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/286513/items/AVP7ICNQ", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/uw_cloud_climate_reading_group/items/AVP7ICNQ", "type": "text/html" } }, "meta": { "createdByUser": { "id": 1249058, "username": "mdwoelfle", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/mdwoelfle", "type": "text/html" } } }, "lastModifiedByUser": { "id": 1949949, "username": "robwood", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/robwood", "type": "text/html" } } }, "creatorSummary": "Qu et al.", "parsedDate": "2014-12-19", "numChildren": 2 }, "data": { "key": "AVP7ICNQ", "version": 96, "itemType": "journalArticle", "title": "The strength of the tropical inversion and its response to climate change in 18 CMIP5 models", "creators": [ { "creatorType": "author", "firstName": "Xin", "lastName": "Qu" }, { "creatorType": "author", "firstName": "Alex", "lastName": "Hall" }, { "creatorType": "author", "firstName": "Stephen A.", "lastName": "Klein" }, { "creatorType": "author", "firstName": "Peter M.", "lastName": "Caldwell" } ], "abstractNote": "We examine the tropical inversion strength, measured by the estimated inversion strength (EIS), and its response to climate change in 18 models associated with phase 5 of the coupled model intercomparison project (CMIP5). While CMIP5 models generally capture the geographic distribution of observed EIS, they systematically underestimate it off the west coasts of continents, due to a warm bias in sea surface temperature. The negative EIS bias may contribute to the low bias in tropical low-cloud cover in the same models. Idealized perturbation experiments reveal that anthropogenic forcing leads directly to EIS increases, independent of “temperature-mediated” EIS increases associated with long-term oceanic warming. This fast EIS response to anthropogenic forcing is strongly impacted by nearly instantaneous continental warming. The temperature-mediated EIS change has contributions from both uniform and non-uniform oceanic warming. The substantial EIS increases in uniform oceanic warming simulations are due to warming with height exceeding the moist adiabatic lapse rate in tropical warm pools. EIS also increases in fully-coupled ocean–atmosphere simulations where CO2\\hbox {CO}_{2} concentration is instantaneously quadrupled, due to both fast and temperature-mediated changes. The temperature-mediated EIS change varies with tropical warming in a nonlinear fashion: The EIS change per degree tropical warming is much larger in the early stage of the simulations than in the late stage, due to delayed warming in the eastern parts of the subtropical oceans. Given the importance of EIS in regulating tropical low-cloud cover, this suggests that the tropical low-cloud feedback may also be nonlinear .", "publicationTitle": "Climate Dynamics", "publisher": "", "place": "", "date": "2014/12/19", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "1-22", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Clim Dyn", "DOI": "10.1007/s00382-014-2441-9", "citationKey": "quStrengthTropicalInversion2014", "url": "http://link.springer.com/article/10.1007/s00382-014-2441-9", "accessDate": "2015-01-22T19:03:48Z", "PMID": "", "PMCID": "", "ISSN": "0930-7575, 1432-0894", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "link.springer.com", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Climatology", "type": 1 }, { "tag": "EIS", "type": 1 }, { "tag": "Fast response", "type": 1 }, { "tag": "Geophysics/Geodesy", "type": 1 }, { "tag": "Oceanography", "type": 1 }, { "tag": "Temperature-mediated change", "type": 1 }, { "tag": "Tropical inversion", "type": 1 } ], "collections": [ "GCIN6MCN" ], "relations": {}, "dateAdded": "2015-01-22T19:03:48Z", "dateModified": "2026-02-17T04:02:31Z" } } ]