e2025WR041790 2025WR041790
", "tags": [], "relations": {}, "dateAdded": "2026-07-10T17:58:25Z", "dateModified": "2026-07-10T17:58:25Z" } }, { "key": "IBL6Q7ZA", "version": 1109, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/IBL6Q7ZA", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/IBL6Q7ZA", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Connolly et al.", "parsedDate": "2026", "numChildren": 0 }, "data": { "key": "IBL6Q7ZA", "version": 1109, "itemType": "journalArticle", "title": "Elucidating the Reactivity and Fate of Dissolved Organic Matter in Groundwater Entering the Alaska Beaufort Sea Coast Using 14C Ramped Oxidation", "creators": [ { "creatorType": "author", "firstName": "C. T.", "lastName": "Connolly" }, { "creatorType": "author", "firstName": "R. G. M.", "lastName": "Spencer" }, { "creatorType": "author", "firstName": "J. W.", "lastName": "McClelland" } ], "abstractNote": "Ramped oxidation and isotopic analysis provide a framework for assessing organic matter transformation and fate across Arctic waters\n\nSupra-permafrost groundwater exhibits an aged but reactive mid...", "publicationTitle": "", "publisher": "", "place": "", "date": "2026", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1029/2025GL121357", "citationKey": "", "url": "https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL121357", "accessDate": "2026-07-10T17:54:11Z", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "agupubs.onlinelibrary.wiley.com", "callNumber": "", "rights": "", "extra": "https://doi.org/10.6073/pasta/a4105a1bd1f8fd167b3f7af7d06ad9f4", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-07-10T17:54:11Z", "dateModified": "2026-07-10T17:56:10Z" } }, { "key": "KPPR866K", "version": 1105, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/KPPR866K", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/KPPR866K", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Mahoney and Einhorn", "parsedDate": "2026", "numChildren": 1 }, "data": { "key": "KPPR866K", "version": 1105, "itemType": "journalArticle", "title": "The Evolving Decline of Landfast Sea Ice in Northern Alaska and Adjacent Waters: Results from an Updated Climatology", "creators": [ { "creatorType": "author", "firstName": "Andrew R.", "lastName": "Mahoney" }, { "creatorType": "author", "firstName": "Andrew H.", "lastName": "Einhorn" } ], "abstractNote": "We present a new 27-year record of landfast sea ice extent in northern Alaska and adjacent waters, which uses ice chart data to extend a previous analysis based on synthetic aperture radar (SAR) imagery. This new climatology provides updated information on the decline of landfast ice in a region of the Arctic that has seen extensive losses of sea ice in recent summers. By comparing our results with early satellite data analysis from the 1970s, we find that trends in the timing of landfast ice have been ongoing for at least 50 years. Over the period 1996–2023, the landfast season shortened by 19 days/decade in the Chukchi Sea and 13 days/decade in the Beaufort Sea, primarily due to later formation of landfast ice. Also, the time between onset of freezing air temperatures and landfast ice formation is increasing, which is consistent with a coastal ocean that takes longer to freeze. While it was previously reported that the typical annual maximum width of landfast ice in the Chukchi Sea declined by 13 km between periods 1970–1976 and 1996–2008, we find this retreat has slowed with a decline of 3.3 km over the course of our data set as few areas of extensive landfast remain to be lost. Conversely, landfast sea ice extent in the Beaufort Sea had previously been found to have remained constant since the 1970s, but we find an average reduction of 2.5 km. We attribute this emergent phenomenon to a reduction in the number grounded ridges forming offshore.", "publicationTitle": "Journal of Geophysical Research: Oceans", "publisher": "", "place": "", "date": "2026", "volume": "131", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "e2025JC022464", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1029/2025JC022464", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1029/2025JC022464", "accessDate": "2026-04-07T17:54:24Z", "PMID": "", "PMCID": "", "ISSN": "2169-9291", "archive": "", "archiveLocation": "", "shortTitle": "The Evolving Decline of Landfast Sea Ice in Northern Alaska and Adjacent Waters", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "© 2026. The Author(s).", "extra": "_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2025JC022464", "tags": [ { "tag": "Alaska", "type": 1 }, { "tag": "Arctic", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Supported" }, { "tag": "fast ice", "type": 1 }, { "tag": "landfast", "type": 1 }, { "tag": "sea ice", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-04-07T17:54:24Z", "dateModified": "2026-04-07T18:06:31Z" } }, { "key": "9HLZGFB3", "version": 1102, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/9HLZGFB3", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/9HLZGFB3", "type": "text/html" }, "up": { "href": "https://api.zotero.org/groups/2211939/items/KPPR866K", "type": "application/json" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "numChildren": 0 }, "data": { "key": "9HLZGFB3", "version": 1102, "parentItem": "KPPR866K", "itemType": "note", "note": "e2025JC022464 2025JC022464
", "tags": [], "relations": {}, "dateAdded": "2026-04-07T17:54:24Z", "dateModified": "2026-04-07T17:54:24Z" } }, { "key": "YZRNL8GM", "version": 1100, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/YZRNL8GM", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/YZRNL8GM", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Rawlins et al.", "parsedDate": "2026", "numChildren": 1 }, "data": { "key": "YZRNL8GM", "version": 1100, "itemType": "journalArticle", "title": "Hydrological Cycle Intensification and Permafrost Thaw Drive Increased Freshwater and Organic Carbon Inputs to Northern Alaska Estuaries", "creators": [ { "creatorType": "author", "firstName": "Michael A.", "lastName": "Rawlins" }, { "creatorType": "author", "firstName": "Craig T.", "lastName": "Connolly" }, { "creatorType": "author", "firstName": "James W.", "lastName": "McClelland" } ], "abstractNote": "Understanding how hydrological inflows and climate change influence individual estuaries across northern Alaska is limited by a paucity of measured data, necessitating the application of suitably scaled numerical process models. This study uses an updated model to quantify freshwater discharge and dissolved organic carbon (DOC) export from the North Slope of Alaska (NSA) to coastal waters of the Beaufort Sea and examines climate-linked temporal changes. The model was applied at 1 \\textkm\\ resolution across the 166,483 {\\textkm^2\\ NSA domain over 1980–2023. Watershed inputs to coastal waters were estimated by routing along river networks to 1,039 outlets at the land-sea boundary. Key simulation parameters were evaluated to demonstrate model efficacy, then spatial and temporal patterns were quantified. Exports to specific lagoons, bays, and sounds demonstrate how landscape composition, terrestrial drainage basin size, and estuary area modulate watershed influence on coastal ecosystems across the region. Freshwater discharge and DOC export increased over the greater than four decades, associated with changes in precipitation and permafrost thaw. Surface and supra-permafrost subsurface fluxes also increased, with pronounced rises in proportional contributions via subsurface flow during summer and autumn. These changes have the potential to substantially impact salinity and trophic conditions along Alaska's Beaufort Sea coast. Our study highlights the value of model-data syntheses that resolve regional-to-local scale fluxes where observational measurements are sparse, and provides novel quantitative export metrics that will be useful to researchers, resource managers, and other stakeholders with interests in the climate, hydrology, and biogeochemistry of coastal northern Alaska.", "publicationTitle": "Global Biogeochemical Cycles", "publisher": "", "place": "", "date": "2026", "volume": "40", "issue": "4", "section": "", "partNumber": "", "partTitle": "", "pages": "e2025GB008822", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1029/2025GB008822", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1029/2025GB008822", "accessDate": "2026-04-01T15:40:07Z", "PMID": "", "PMCID": "", "ISSN": "1944-9224", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "© 2026. The Author(s).", "extra": "_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2025GB008822\n\nhttps://doi.org/10.6073/pasta/357705281a44f92f643e4d7f5b29ed82", "tags": [ { "tag": "Arctic", "type": 1 }, { "tag": "DOC", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Supported" }, { "tag": "climate", "type": 1 }, { "tag": "hydrology", "type": 1 }, { "tag": "permafrost", "type": 1 }, { "tag": "rivers", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-04-01T15:40:07Z", "dateModified": "2026-04-01T15:40:53Z" } }, { "key": "JFKW9NAJ", "version": 1098, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/JFKW9NAJ", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/JFKW9NAJ", "type": "text/html" }, "up": { "href": "https://api.zotero.org/groups/2211939/items/YZRNL8GM", "type": "application/json" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "numChildren": 0 }, "data": { "key": "JFKW9NAJ", "version": 1098, "parentItem": "YZRNL8GM", "itemType": "note", "note": "e2025GB008822 2025GB008822
", "tags": [], "relations": {}, "dateAdded": "2026-04-01T15:40:07Z", "dateModified": "2026-04-01T15:40:07Z" } }, { "key": "IYHTU3PZ", "version": 1096, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/IYHTU3PZ", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/IYHTU3PZ", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Marvy et al.", "parsedDate": "2026", "numChildren": 1 }, "data": { "key": "IYHTU3PZ", "version": 1096, "itemType": "journalArticle", "title": "Contrasting CO2 Fluxes Among Arctic Pond Types Are Driven by Differences in Carbon Lability, Terrestrial Inputs, and Benthic Respiration", "creators": [ { "creatorType": "author", "firstName": "Asher J.", "lastName": "Marvy" }, { "creatorType": "author", "firstName": "Christian G.", "lastName": "Andresen" }, { "creatorType": "author", "firstName": "Alina C.", "lastName": "Spera" }, { "creatorType": "author", "firstName": "Vanessa L.", "lastName": "Lougheed" } ], "abstractNote": "Small freshwater tundra ponds are hotspots for greenhouse gas release into the atmosphere. As the Arctic warms, thermokarst processes drive changes in tundra pond geomorphology, with implications for their contribution to carbon cycling in these regions. To understand how these morphological changes affect pond biogeochemistry, we compared low-centered polygonal (LCP) ponds and thermokarst trough (TKT) ponds that are formed through ice-wedge permafrost thaw. We found substantially higher levels of carbon, nutrients, and algal biomass in TKT ponds as compared to LCP ponds located in the Arctic Coastal Plain near Utqiaġvik, AK. These differences were likely driven by TKT ponds receiving increased terrestrial inputs due to discrete thermokarst events and slumping, lateral inflow of carbon and nutrients from surrounding soils, higher lability of TKT carbon, and greater rates of benthic respiration. Together, these factors create ponds that are more productive and greater sources of CO2 to the atmosphere than LCPs. During the peak growing season (July-August), CO2 uptake from macrophyte-dominated habitat in LCP ponds compensates for CO2 release from open water, making LCP ponds net CO2 sinks (−4 ± 3 gCO2/m2/d), whereas TKT ponds are CO2 sources (3 ± 6 gCO2/m2/d), despite TKT macrophyte-dominated habitat also being a site of CO2 uptake. The net atmospheric greenhouse gas contribution of these ponds will likely be altered with high latitude warming, as air temperature influenced factors including vegetation cover, precipitation, water temperature, and thermokarsting alter rates of CO2 flux from tundra ponds.", "publicationTitle": "Journal of Geophysical Research: Biogeosciences", "publisher": "", "place": "", "date": "2026", "volume": "131", "issue": "3", "section": "", "partNumber": "", "partTitle": "", "pages": "e2025JG009318", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1029/2025JG009318", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1029/2025JG009318", "accessDate": "2026-03-16T13:17:08Z", "PMID": "", "PMCID": "", "ISSN": "2169-8961", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "© 2026. American Geophysical Union. All Rights Reserved.", "extra": "_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2025JG009318\n\nhttps://doi.org/10.6073/pasta/4ff0d5ca036fcf28e3710d86468420e7", "tags": [ { "tag": "Arctic", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Supported" }, { "tag": "biogeochemistry", "type": 1 }, { "tag": "carbon flux", "type": 1 }, { "tag": "thermokarst", "type": 1 }, { "tag": "tundra ponds", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-03-16T13:17:08Z", "dateModified": "2026-03-16T13:34:48Z" } }, { "key": "T4AXFXP3", "version": 1093, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/T4AXFXP3", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/T4AXFXP3", "type": "text/html" }, "up": { "href": "https://api.zotero.org/groups/2211939/items/IYHTU3PZ", "type": "application/json" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "numChildren": 0 }, "data": { "key": "T4AXFXP3", "version": 1093, "parentItem": "IYHTU3PZ", "itemType": "note", "note": "e2025JG009318 2025JG009318
", "tags": [], "relations": {}, "dateAdded": "2026-03-16T13:17:08Z", "dateModified": "2026-03-16T13:17:08Z" } }, { "key": "FCKQ23HD", "version": 1006, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/FCKQ23HD", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/FCKQ23HD", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Stanek et al.", "parsedDate": "2024", "numChildren": 0 }, "data": { "key": "FCKQ23HD", "version": 1006, "itemType": "journalArticle", "title": "Arctic fishes reveal patterns in radiocarbon age across habitats and with recent climate change", "creators": [ { "creatorType": "author", "firstName": "Ashley E.", "lastName": "Stanek" }, { "creatorType": "author", "firstName": "Jonathan A.", "lastName": "O'Donnell" }, { "creatorType": "author", "firstName": "Michael P.", "lastName": "Carey" }, { "creatorType": "author", "firstName": "Sarah M.", "lastName": "Laske" }, { "creatorType": "author", "firstName": "Xiaomei", "lastName": "Xu" }, { "creatorType": "author", "firstName": "Kenneth H.", "lastName": "Dunton" }, { "creatorType": "author", "firstName": "Vanessa R.", "lastName": "von Biela" } ], "abstractNote": "Climate change alters the sources and age of carbon in Arctic food webs by fostering the release of older carbon from degrading permafrost. Radiocarbon (14C) traces carbon sources and age, but data before rapid warming are rare and limit assessments over time. We capitalized on 14C data collected 40 years ago that used fish as natural samplers by resampling the same species today. Among resampled fish, those using freshwater food webs had the oldest 14C ages (> 1000 yr BP), while those using marine food webs had the youngest 14C ages (near modern). One migratory species encompassed the entire range of 14C ages because juveniles fed in freshwater streams and adults fed in offshore marine habitats. Over 40 yr, average 14C ages of freshwater and marine feeding fish shifted closer to atmospheric values, suggesting a potential influence from “greening of the Arctic.”", "publicationTitle": "Limnology and Oceanography Letters", "publisher": "", "place": "", "date": "2024", "volume": "9", "issue": "6", "section": "", "partNumber": "", "partTitle": "", "pages": "796-805", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/lol2.10442", "citationKey": "", "url": "https://doi.org/10.1002/lol2.10442", "accessDate": "2026-01-26T21:13:14Z", "PMID": "", "PMCID": "", "ISSN": "2378-2242", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "", "extra": "_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lol2.10442", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-01-26T21:13:14Z", "dateModified": "2026-01-26T21:48:50Z" } }, { "key": "GHZSEHSF", "version": 1091, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/GHZSEHSF", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/GHZSEHSF", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Bagavathyraj et al.", "parsedDate": "2026-01-21", "numChildren": 0 }, "data": { "key": "GHZSEHSF", "version": 1091, "itemType": "journalArticle", "title": "Segmentation of arctic coastal shoreline and bluff edges using optical satellite imagery and deep learning", "creators": [ { "creatorType": "author", "firstName": "Harshavardhini", "lastName": "Bagavathyraj" }, { "creatorType": "author", "firstName": "Sergio", "lastName": "Vargas Zesati" }, { "creatorType": "author", "firstName": "Olac", "lastName": "Fuentes" }, { "creatorType": "author", "firstName": "Sasha", "lastName": "Peterson" }, { "creatorType": "author", "firstName": "Craig E.", "lastName": "Tweedie" } ], "abstractNote": "The Arctic coastline spans multiple countries, supports Indigenous livelihoods, and plays a vital role in the Arctic system. Rapid climate change is accelerating permafrost thaw, sea-level rise, and coastal erosion, underscoring the need for decision making to be informed by accurate delineation of tundra shoreline (instantaneous water line) and bluff edge (vegetation–slope boundary) position and change trends. To address this need, we compared two image segmentation approaches for mapping Arctic land and water interfaces from high-resolution satellite imagery. (1) U-Net, a supervised convolutional neural network trained on expert-annotated scenes, and (2) Differentiable Feature Clustering (DifFeat), an unsupervised model applied in a minimally supervised manner via expert-guided cluster selection. The shoreline and bluff edge boundaries were derived from the segmented land and water masks using an automated interface extraction approach. DifFeat achieved higher segmentation accuracy, with IoU values of 0.95 (water) and 0.92 (land), compared to U-Net’s 0.58 and 0.50, respectively. U-Net produced reliable results and benefited from infrared and vegetation spectral indices, but required extensive annotation and showed limited generalization to UAV imagery. DifFeat achieved superior results without manual annotation, reducing the dependence on labeled data and completing training 99.87% faster than U-Net. These findings highlight the complementary strengths of supervised and semi-supervised models for Arctic coastal mapping, with DifFeat offering a scalable, label-efficient solution for long-term coastal-change monitoring. Future work will integrate elevation data to further improve bluff edge feature detection.", "publicationTitle": "Frontiers in Environmental Science", "publisher": "Frontiers", "place": "", "date": "2026-01-21", "volume": "13", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Front. Environ. Sci.", "DOI": "10.3389/fenvs.2025.1657984", "citationKey": "", "url": "https://doi.org/10.3389/fenvs.2025.1657984", "accessDate": "2026-01-22T16:03:03Z", "PMID": "", "PMCID": "", "ISSN": "2296-665X", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "English", "libraryCatalog": "Frontiers", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" }, { "tag": "U-Net", "type": 1 }, { "tag": "bluff edge", "type": 1 }, { "tag": "deep learning", "type": 1 }, { "tag": "differentiable feature clustering", "type": 1 }, { "tag": "satellite imagery", "type": 1 }, { "tag": "segmentation", "type": 1 }, { "tag": "shoreline", "type": 1 }, { "tag": "unsupervised learning", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-01-22T16:03:03Z", "dateModified": "2026-01-22T16:27:57Z" } }, { "key": "ZM8UNBU6", "version": 983, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/ZM8UNBU6", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/ZM8UNBU6", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Spera et al.", "parsedDate": "2026-01-20", "numChildren": 0 }, "data": { "key": "ZM8UNBU6", "version": 983, "itemType": "journalArticle", "title": "Wind-driven Circulation Impacts Water Quality and pCO2 Over an Estuarine Gradient in an Arctic Lagoon", "creators": [ { "creatorType": "author", "firstName": "Alina", "lastName": "Spera" }, { "creatorType": "author", "firstName": "Sasha", "lastName": "Peterson" }, { "creatorType": "author", "firstName": "Craig", "lastName": "Tweedie" }, { "creatorType": "author", "firstName": "Vanessa", "lastName": "Lougheed" } ], "abstractNote": "Arctic carbon (C) budgets typically exclude estuarine and coastal CO2 dynamics despite evidence that these systems can be a source of atmospheric CO2, unlike the shelf waters and the open ocean. High frequency measurements of Arctic coastal pCO2 are limited but needed to understand C cycling responses to interacting influences of terrestrial and oceanic inputs. We measured continuous pCO2 and estimated CO2 fluxes during three open water seasons at five sites across an Arctic estuary, including three shallow sites (≤ 1 m), and two deep sites (> 2 m). During the open water season, wind-driven currents controlled the distribution of terrestrial and marine materials, which influenced spatial and temporal patterns - both daily and interannual - in lagoon water quality. Lagoon waters generally had undersaturated pCO₂ relative to the atmosphere, particularly at the deeper sites. pCO₂ increased or reached saturation at all sites when wind-driven circulation enhanced terrestrial influence that led to warmer, fresher conditions with elevated light attenuation and higher apparent oxygen utilization. On average, two shallow sites were sources of CO2 to the atmosphere, potentially due to their proximity to eroding coastal bluffs, inputs from an intermediate-sized river, and wind driven resuspension events. Continuous measurements and high spatial coverage are important to detect and scale CO2 fluxes across the open water season in the Arctic nearshore zone, especially those draining understudied, smaller watersheds.", "publicationTitle": "Estuaries and Coasts", "publisher": "", "place": "", "date": "2026-01-20", "volume": "49", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "49", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Estuaries and Coasts", "DOI": "10.1007/s12237-025-01662-6", "citationKey": "", "url": "https://doi.org/10.1007/s12237-025-01662-6", "accessDate": "2026-01-20T21:08:08Z", "PMID": "", "PMCID": "", "ISSN": "1559-2731", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Springer Link", "callNumber": "", "rights": "", "extra": "https://doi.org/10.6073/pasta/bd140df496a851ced06f8f03445f73ab", "tags": [ { "tag": "Arctic lagoon", "type": 1 }, { "tag": "CO2 flux, light attenuation", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Supported" }, { "tag": "Wind-driven circulation", "type": 1 }, { "tag": "pCO2 dynamics", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-01-20T21:08:08Z", "dateModified": "2026-01-20T21:10:03Z" } }, { "key": "CG6PUKB8", "version": 978, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/CG6PUKB8", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/CG6PUKB8", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Spera et al.", "parsedDate": "2025-12-15", "numChildren": 0 }, "data": { "key": "CG6PUKB8", "version": 978, "itemType": "journalArticle", "title": "Saltwater inundation's concurrent effects on below-ground thermal hydrology and above-ground properties of Arctic coastal tundra", "creators": [ { "creatorType": "author", "firstName": "Alina C.", "lastName": "Spera" }, { "creatorType": "author", "firstName": "James W.", "lastName": "McClelland" }, { "creatorType": "author", "firstName": "Cansu", "lastName": "Demir" }, { "creatorType": "author", "firstName": "M. Bayani", "lastName": "Cardenas" }, { "creatorType": "author", "firstName": "Julia A.", "lastName": "Guimond" } ], "abstractNote": "Coastal flooding and saltwater intrusion (SWI) pose growing threats to Arctic coastal permafrost, yet their long-term impacts remain poorly understood. While prior studies focused on surface effects like vegetation dieback or lake salinization, subsurface hydrothermal observations in salinized coastal tundra are lacking. This study investigates both surface and subsurface effects of SWI on tundra and active layer thermal regimes in an area with previously recorded impacts from recurring seawater inundation. Seawater flooding in the study area was driven by western winds; flooding intensity and frequency varied along an elevation gradient, influencing vegetation cover and porewater salinity. Low-lying, frequently inundated areas had sparse vegetation and mineral sediment deposition, while higher elevation areas remained non-salinized with high vegetation cover, as indicated by NDVI. Frequently flooded sites had deeper thaw depths, and temperature profiles revealed these areas experienced summer soil temperatures up to 12 °C warmer than non-inundated sites. We attribute increased ground heat flux to a combination of a lack of vegetation, which reduces ground insulation and shading, and increased thermal diffusivity from mineral sediment deposition during inundation. These findings uncover an overlooked feedback loop between elevation, salinization, and tundra active layer thermal regime. Inundation frequency and coastal land loss will likely increase in response to changing climate. This study highlights SWI as an emerging threat to coastal Arctic resilience by revealing its coupled surface and subsurface thermal impacts.", "publicationTitle": "Science of The Total Environment", "publisher": "", "place": "", "date": "2025-12-15", "volume": "1008", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "180906", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Science of The Total Environment", "DOI": "10.1016/j.scitotenv.2025.180906", "citationKey": "", "url": "https://doi.org/10.1016/j.scitotenv.2025.180906", "accessDate": "2026-01-08T19:45:40Z", "PMID": "", "PMCID": "", "ISSN": "0048-9697", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "ScienceDirect", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Arctic coasts", "type": 1 }, { "tag": "Coastal flooding", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Permafrost", "type": 1 }, { "tag": "Saltwater intrusion", "type": 1 }, { "tag": "Supported" }, { "tag": "Thermal hydrology", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-01-08T19:45:40Z", "dateModified": "2026-01-08T20:07:01Z" } }, { "key": "7JRLZ8HH", "version": 1090, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/7JRLZ8HH", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/7JRLZ8HH", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Bristol et al.", "parsedDate": "2026-01-06", "numChildren": 0 }, "data": { "key": "7JRLZ8HH", "version": 1090, "itemType": "journalArticle", "title": "Supra-Permafrost Groundwater is a Source of Highly Biodegradable Dissolved Organic Matter to the Arctic Ocean", "creators": [ { "creatorType": "author", "firstName": "Emily M.", "lastName": "Bristol" }, { "creatorType": "author", "firstName": "Megan I.", "lastName": "Behnke" }, { "creatorType": "author", "firstName": "Robert G.M.", "lastName": "Spencer" }, { "creatorType": "author", "firstName": "Amy M.", "lastName": "McKenna" }, { "creatorType": "author", "firstName": "Matthew A.", "lastName": "Charette" }, { "creatorType": "author", "firstName": "M. Bayani", "lastName": "Cardenas" }, { "creatorType": "author", "firstName": "James W.", "lastName": "McClelland" } ], "abstractNote": "Supra-permafrost groundwater (SPGW) flowing through seasonally thawed soils is an important source of dissolved organic matter (DOM) to the Arctic Ocean, yet few studies have investigated the quality of this DOM. We sampled SPGW, runoff, and rivers near Simpson Lagoon, Alaska, during spring ice breakup, summer open water, and fall freeze-up seasons. Through incubation experiments, we compared biodegradable DOC (BDOC) across sources and seasons and linked these results with DOM composition using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). DOM composition was distinctly different between SPGW and rivers and shifted throughout the year. SPGW contained an order of magnitude more dissolved organic carbon (DOC) than rivers, with average concentrations increasing from breakup (22 ± 5 mg C L–1) to freeze-up (110 ± 42 mg C L–1). SPGW also contained three times or more BDOC than rivers, averaging 18 ± 1% during breakup and declining to 3.4 ± 0.7% during freeze-up. BDOC was positively correlated with condensed aromatic and polyphenolic DOM formula classes that are often associated with recalcitrant organic matter. Thus, SPGW DOM is highly aromatic yet biodegradable and is likely an important energy source to Arctic coastal waters in summer when river inputs are low.", "publicationTitle": "Environmental Science & Technology", "publisher": "American Chemical Society", "place": "", "date": "2026-01-06", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Environ. Sci. Technol.", "DOI": "10.1021/acs.est.5c08206", "citationKey": "", "url": "https://doi.org/10.1021/acs.est.5c08206", "accessDate": "2026-01-08T19:53:10Z", "PMID": "", "PMCID": "", "ISSN": "0013-936X", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "ACS Publications", "callNumber": "", "rights": "", "extra": "https://doi.org/10.6073/pasta/c0a48cbd0edbd56396a2b524d6fb7347", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2026-01-08T19:53:10Z", "dateModified": "2026-01-08T20:05:37Z" } }, { "key": "F5ALFAQD", "version": 1079, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/F5ALFAQD", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/F5ALFAQD", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "McTigue et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "F5ALFAQD", "version": 1079, "itemType": "journalArticle", "title": "Trophic niche variation across the pan-Arctic coastal continuum", "creators": [ { "creatorType": "author", "firstName": "Nathan D.", "lastName": "McTigue" }, { "creatorType": "author", "firstName": "Katrin", "lastName": "Iken" }, { "creatorType": "author", "firstName": "Ashley", "lastName": "Ehrman" }, { "creatorType": "author", "firstName": "Bodil A.", "lastName": "Bluhm" }, { "creatorType": "author", "firstName": "Guillaume", "lastName": "Bridier" }, { "creatorType": "author", "firstName": "Rolf", "lastName": "Gradinger" }, { "creatorType": "author", "firstName": "Joanna", "lastName": "Legeżyńska" }, { "creatorType": "author", "firstName": "Maeve", "lastName": "McGovern" }, { "creatorType": "author", "firstName": "Bailey", "lastName": "McMeans" }, { "creatorType": "author", "firstName": "Frédéric", "lastName": "Olivier" }, { "creatorType": "author", "firstName": "Amanda", "lastName": "Poste" }, { "creatorType": "author", "firstName": "Paul E.", "lastName": "Renaud" }, { "creatorType": "author", "firstName": "Virginie", "lastName": "Roy" }, { "creatorType": "author", "firstName": "Janne E.", "lastName": "Søreide" }, { "creatorType": "author", "firstName": "Maria", "lastName": "Włodarska-Kowalczuk" }, { "creatorType": "author", "firstName": "Kenneth H.", "lastName": "Dunton" } ], "abstractNote": "We analyzed stable carbon and nitrogen isotope values (δ13C and δ15N, respectively) for pan-Arctic coastal primary producers and consumers to detect large-scale regional trends both temporally and spatially. To facilitate comparison, we grouped coastal habitats into fjords, lagoons, shelves, and straits as four “coastscapes”. We gathered over 12,000 rows of data collected over 24 years (between 1999 and 2022) from 34 different field campaigns across the coastal Arctic (63 to 81°N and 177°W to 33°E). Our goal was to examine the isotopic patterns in pelagic and sediment particulate organic matter (pPOM and sPOM, respectively) and four consumer groups (deposit feeders, opportunists/scavengers, predators, and suspension feeders) among the four coastscapes. We found that despite the enormous spatial range of data, both pPOM and sPOM became 2.1‰ and 2.2‰ more 13C-depleted per decade, respectively, with parallel decreases in the δ13C values in consumers. The significant decrease is likely attributed to the increased contributions of 13C-depleted terrestrial organic matter across the Arctic coasts from freshwater inputs and coastal erosion in concert with diminishing sea ice that supports sympagic microalgae. Across all Arctic coastscapes, consumer groups exhibited overlapping isotopic composition, notably with wide δ13C ranges that indicated assimilation of multiple organic matter sources, including terrestrial organic matter, organic matter derived from marine phytoplankton and sea ice algae, macroalgae, and potentially benthic microalgae or degraded organic matter. This consistent pattern across coastscapes provides evidence of the trophic plasticity possessed by Arctic consumers, how coastal food webs respond to climate warming, and the signature of terrestrialization imprinted on the pan-Arctic coastal isoscape.", "publicationTitle": "PLOS ONE", "publisher": "Public Library of Science", "place": "", "date": "2025", "volume": "20", "issue": "11", "section": "", "partNumber": "", "partTitle": "", "pages": "e0335406", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "PLOS ONE", "DOI": "10.1371/journal.pone.0335406", "citationKey": "", "url": "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0335406", "accessDate": "2025-12-03T15:52:08Z", "PMID": "", "PMCID": "", "ISSN": "1932-6203", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "PLoS Journals", "callNumber": "", "rights": "", "extra": "https://doi.org/10.6073/pasta/48570e835463e405c707a4905c9d172d\nhttps://doi.org/10.6073/pasta/04a064bbea70a0ec24cad6c1418e57bf\nhttps://doi.org/10.6073/pasta/f3efc9d88150bd0e8c0814b22ada0e70\nhttps://doi.org/10.6073/pasta/b13ba73e1b97747c644ff8825b1e2704", "tags": [ { "tag": "Algae", "type": 1 }, { "tag": "Eating habits", "type": 1 }, { "tag": "Food", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Lagoons", "type": 1 }, { "tag": "Linear regression analysis", "type": 1 }, { "tag": "Lipids", "type": 1 }, { "tag": "Phytoplankton", "type": 1 }, { "tag": "Stable isotopes", "type": 1 }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2025-12-03T15:52:08Z", "dateModified": "2025-12-03T18:38:19Z" } }, { "key": "2T8RFEF5", "version": 858, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/2T8RFEF5", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/2T8RFEF5", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Stanek et al.", "parsedDate": "2025-09-17", "numChildren": 0 }, "data": { "key": "2T8RFEF5", "version": 858, "itemType": "journalArticle", "title": "Energetic value of Arctic forage-sized fish with implications for a nearshore seabird predator", "creators": [ { "creatorType": "author", "firstName": "Ashley E.", "lastName": "Stanek" }, { "creatorType": "author", "firstName": "Brian D.", "lastName": "Uher-Koch" }, { "creatorType": "author", "firstName": "Kenneth H.", "lastName": "Dunton" }, { "creatorType": "author", "firstName": "Vanessa R.", "lastName": "von Biela" } ], "abstractNote": "Arctic cod (Boreogadus saida, also called polar cod) are considered the single most important Arctic forage fish due to their high abundance and nutritional quality. Because Arctic cod are strongly ice associated and prefer colder waters, their frequency in coastal waters has declined with warming, decreasing availability to nearshore predators. To consider the nutritional quality of alternative prey, we measured energy density and estimated whole-body energy of forage-size (39–200 mm) fishes collected during summers 2021–2023 (n = 274). The fishes sampled included 16 potential prey species from Foggy Island Bay (70.3°N, 147.5°W, near Prudhoe Bay) and Lion Bay (70.2°N, 146.4°W, near Flaxman Island), northern Alaska. Dry weight energy densities ranged from 16.2 to 27.5 kJ g-1 (mean ± SD = 22.0 ± 1.73 kJ g-1, n = 274) across individuals. Of common species, Arctic cod had the highest mean energy density (24.3 ± 1.1 kJ g-1, n = 25) and fourhorn sculpin (Myoxocephalus quadricornis) had the lowest (19.7 ± 0.8 kJ g-1, n = 20). To account for size differences among prey species, whole-body energy of typical fish sizes available to predators were modeled using whole-body energy to length relationships and length distributions. Juvenile salmonids (e.g., ciscoes and whitefishes) provided the most energy per individual and were four-fold greater than smaller-bodied Arctic cod. Predators that consume juvenile ciscoes and whitefishes may be more resilient to declines in Arctic cod availability than predators with smaller gapes.", "publicationTitle": "Marine Biology", "publisher": "", "place": "", "date": "2025-09-17", "volume": "172", "issue": "10", "section": "", "partNumber": "", "partTitle": "", "pages": "157", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Mar Biol", "DOI": "10.1007/s00227-025-04705-5", "citationKey": "", "url": "https://doi.org/10.1007/s00227-025-04705-5", "accessDate": "2025-09-26T21:15:10Z", "PMID": "", "PMCID": "", "ISSN": "1432-1793", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Springer Link", "callNumber": "", "rights": "", "extra": "https://doi.org/10.5066/P13ELTUB", "tags": [ { "tag": "Arctic", "type": 1 }, { "tag": "Energy content", "type": 1 }, { "tag": "Energy density", "type": 1 }, { "tag": "Forage fish", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Predator", "type": 1 }, { "tag": "Seabird", "type": 1 }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2025-09-26T21:15:10Z", "dateModified": "2025-12-03T04:23:05Z" } }, { "key": "3L68G6CL", "version": 841, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/3L68G6CL", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/3L68G6CL", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Griffin et al.", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "3L68G6CL", "version": 841, "itemType": "journalArticle", "title": "Quantitative metatranscriptomics and biogeochemical rate measurements reveal microbial pathways driving carbon and nitrogen cycles in an Arctic coastal lagoon", "creators": [ { "creatorType": "author", "firstName": "Natasha A.", "lastName": "Griffin" }, { "creatorType": "author", "firstName": "Brian", "lastName": "Kim" }, { "creatorType": "author", "firstName": "Amber K.", "lastName": "Hardison" }, { "creatorType": "author", "firstName": "Byron C.", "lastName": "Crump" } ], "abstractNote": "Microbial communities in Arctic coastal lagoons mediate nitrogen and carbon cycling at the terrestrial–marine interface of these rapidly changing ecosystems. To investigate these microbial processes, we measured gene expression, nitrification, and inorganic carbon assimilation in waters of Elson Lagoon on the Beaufort Sea coast under ice cover (April), during spring break-up (July), and in open water (August). Quantitative metatranscriptomics with internal controls quantified per-liter transcript abundances alongside in situ light and dark 15N-ammonium, 15N-urea, and 13C-bicarbonate stable isotope tracer incubations. Nitrification was only detectable during ice cover, showing high rates for Arctic coastal systems and evidence of light inhibition. Although carbon assimilation was relatively low during ice cover, dark carbon assimilation accounted for nearly half of total uptake, matching estimates of chemoautotrophic potential based on nitrification. Microbial gene expression also shifted seasonally in abundance and function. Transcripts for nitrification peaked during ice cover when genes for ammonia oxidation and 3-HP/4-HB carbon fixation were primarily expressed by archaeal genus Nitrosopumilus, while those for nitrite oxidation and reverse TCA carbon fixation were expressed by bacterial phylum Nitrospinota. During break-up and open water, expression shifted toward urea metabolism, nitrogen assimilation, Calvin Cycle carbon fixation, and anaplerotic pathways. These shifts highlight the seasonality of microbial metabolic strategies and reveal distinct functional shifts across the Arctic lagoon seasonal cycle. The findings suggest that ongoing warming and declining ice cover may reduce chemoautotrophic activity and alter nitrogen and carbon cycling under future conditions, with implications for nutrient dynamics and primary production in Arctic coastal ecosystems.", "publicationTitle": "Limnology and Oceanography", "publisher": "", "place": "", "date": "2025", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/lno.70257", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1002/lno.70257", "accessDate": "2025-11-03T15:28:36Z", "PMID": "", "PMCID": "", "ISSN": "1939-5590", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "© 2025 Association for the Sciences of Limnology and Oceanography.", "extra": "_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.70257\nhttps://doi.org/10.6073/pasta/ed9f09370160c6d496ffa74b880021c5", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2025-11-03T15:28:36Z", "dateModified": "2025-11-05T15:48:37Z" } }, { "key": "W4MFBUJY", "version": 1076, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/W4MFBUJY", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/W4MFBUJY", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Donahue et al.", "parsedDate": "2023-11-17", "numChildren": 0 }, "data": { "key": "W4MFBUJY", "version": 1076, "itemType": "journalArticle", "title": "Deep learning estimation of northern hemisphere soil freeze-thaw dynamics using satellite multi-frequency microwave brightness temperature observations", "creators": [ { "creatorType": "author", "firstName": "Kellen", "lastName": "Donahue" }, { "creatorType": "author", "firstName": "John S.", "lastName": "Kimball" }, { "creatorType": "author", "firstName": "Jinyang", "lastName": "Du" }, { "creatorType": "author", "firstName": "Fredrick", "lastName": "Bunt" }, { "creatorType": "author", "firstName": "Andreas", "lastName": "Colliander" }, { "creatorType": "author", "firstName": "Mahta", "lastName": "Moghaddam" }, { "creatorType": "author", "firstName": "Jesse", "lastName": "Johnson" }, { "creatorType": "author", "firstName": "Youngwook", "lastName": "Kim" }, { "creatorType": "author", "firstName": "Michael A.", "lastName": "Rawlins" } ], "abstractNote": "Satellite microwave sensors are well suited for monitoring landscape freeze-thaw (FT) transitions owing to the strong brightness temperature (TB) or backscatter response to changes in liquid water abundance between predominantly frozen and thawed conditions. The FT retrieval is also a sensitive climate indicator with strong biophysical importance. However, retrieval algorithms can have difficulty distinguishing the FT status of soils from that of overlying features such as snow and vegetation, while variable land conditions can also degrade performance. Here, we applied a deep learning model using a multilayer convolutional neural network driven by AMSR2 and SMAP TB records, and trained on surface (~0–5 cm depth) soil temperature FT observations. Soil FT states were classified for the local morning (6 a.m.) and evening (6 p.m.) conditions corresponding to SMAP descending and ascending orbital overpasses, mapped to a 9 km polar grid spanning a five-year (2016–2020) record and Northern Hemisphere domain. Continuous variable estimates of the probability of frozen or thawed conditions were derived using a model cost function optimized against FT observational training data. Model results derived using combined multi-frequency (1.4, 18.7, 36.5 GHz) TBs produced the highest soil FT accuracy over other models derived using only single sensor or single frequency TB inputs. Moreover, SMAP L-band (1.4 GHz) TBs provided enhanced soil FT information and performance gain over model results derived using only AMSR2 TB inputs. The resulting soil FT classification showed favorable and consistent performance against soil FT observations from ERA5 reanalysis (mean percent accuracy, MPA: 92.7%) and in situ weather stations (MPA: 91.0%). The soil FT accuracy was generally consistent between morning and afternoon predictions and across different land covers and seasons. The model also showed better FT accuracy than ERA5 against regional weather station measurements (91.0% vs. 86.1% MPA). However, model confidence was lower in complex terrain where FT spatial heterogeneity was likely beneath the effective model grain size. Our results provide a high level of precision in mapping soil FT dynamics to improve understanding of complex seasonal transitions and their influence on ecological processes and climate feedbacks, with the potential to inform Earth system model predictions.", "publicationTitle": "Frontiers in Big Data", "publisher": "Frontiers", "place": "", "date": "2023-11-17", "volume": "6", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Front. Big Data", "DOI": "10.3389/fdata.2023.1243559", "citationKey": "", "url": "https://www.frontiersin.org/journals/big-data/articles/10.3389/fdata.2023.1243559/full", "accessDate": "2025-09-26T20:43:49Z", "PMID": "", "PMCID": "", "ISSN": "2624-909X", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "English", "libraryCatalog": "Frontiers", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "AMSR", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Microwave", "type": 1 }, { "tag": "Neural Network", "type": 1 }, { "tag": "SMAP", "type": 1 }, { "tag": "Supported" }, { "tag": "machine learning", "type": 1 }, { "tag": "soil freeze-thaw", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2025-09-26T20:43:49Z", "dateModified": "2025-09-26T20:56:43Z" } }, { "key": "CB8AZ3X8", "version": 831, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/CB8AZ3X8", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/CB8AZ3X8", "type": "text/html" } }, "meta": { "createdByUser": { "id": 13908241, "username": "Induja.UT", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/induja.ut", "type": "text/html" } } }, "creatorSummary": "Laske et al.", "parsedDate": "2024-06-01", "numChildren": 0 }, "data": { "key": "CB8AZ3X8", "version": 831, "itemType": "journalArticle", "title": "Local environmental conditions structured discrete fish assemblages in Arctic lagoons", "creators": [ { "creatorType": "author", "firstName": "Sarah M.", "lastName": "Laske" }, { "creatorType": "author", "firstName": "Vanessa R.", "lastName": "von Biela" }, { "creatorType": "author", "firstName": "Ashley E.", "lastName": "Stanek" }, { "creatorType": "author", "firstName": "Kenneth H.", "lastName": "Dunton" } ], "abstractNote": "Rapid changes in sea ice extent and changes in freshwater inputs from land are rapidly changing the nature of Arctic estuarine ecosystems. In the Beaufort Sea, these nearshore habitats are known for their high productivity and mix of marine resident and diadromous fishes that have great subsistence value for Indigenous communities. There is, however, a lack of information on the spatial variation among Arctic nearshore fish communities as related to environmental drivers. In summers of 2017–2019, we sampled fishes in four estuarine ecosystems to assess community composition and relate fish abundance to temperature, salinity, and wind conditions. We found fish communities were heterogeneous over larger spatial extents with rivers forming fresh estuarine plumes that supported diadromous species (e.g., broad whitefish Coregonus nasus), while lagoons with reduced freshwater input and higher salinities were associated with marine species (e.g., saffron cod Eleginus gracilis). West–East directional winds accounted for up to 66% of the community variation, indicating importance of the wind-driven balance between fresh and marine water masses. Salinity and temperature accounted for up to 54% and 37% of the variation among lagoon communities, respectively. Recent sea ice declines provide more opportunity for wind to influence oceanographic conditions and biological communities. Current subsistence practices, future commercial fishing opportunities, and on-going oil and gas activities benefit from a better understanding of current fish community distributions. This work provides important data on fish spatial distributions and community composition, providing a basis for fish community response to changing climatic conditions and anthropogenic use.", "publicationTitle": "Polar Biology", "publisher": "", "place": "", "date": "2024-06-01", "volume": "47", "issue": "6", "section": "", "partNumber": "", "partTitle": "", "pages": "551-568", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Polar Biol", "DOI": "10.1007/s00300-024-03239-8", "citationKey": "", "url": "https://doi.org/10.1007/s00300-024-03239-8", "accessDate": "2025-09-26T20:44:01Z", "PMID": "", "PMCID": "", "ISSN": "1432-2056", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Springer Link", "callNumber": "", "rights": "", "extra": "", "tags": [ { "tag": "Beaufort Sea", "type": 1 }, { "tag": "Community composition", "type": 1 }, { "tag": "Estuarine", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "Salinity", "type": 1 }, { "tag": "Supported" }, { "tag": "Wind", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5", "L9LZINFS" ], "relations": {}, "dateAdded": "2025-09-26T20:44:01Z", "dateModified": "2025-09-26T20:56:43Z" } }, { "key": "7FF94P4F", "version": 808, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/7FF94P4F", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/7FF94P4F", "type": "text/html" } }, "meta": { "createdByUser": { "id": 5056957, "username": "BLE-IM", "name": "Tim Whiteaker", "links": { "alternate": { "href": "https://www.zotero.org/ble-im", "type": "text/html" } } }, "creatorSummary": "Spera and Lougheed", "parsedDate": "2025", "numChildren": 0 }, "data": { "key": "7FF94P4F", "version": 808, "itemType": "journalArticle", "title": "Carbon dioxide fluxes of Arctic coastal ecosystems controlled by seasonal patterns of land-to-ocean connectivity", "creators": [ { "creatorType": "author", "firstName": "Alina C.", "lastName": "Spera" }, { "creatorType": "author", "firstName": "Vanessa L.", "lastName": "Lougheed" } ], "abstractNote": "", "publicationTitle": "Limnology and Oceanography", "publisher": "", "place": "", "date": "2025", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1002/lno.70101", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1002/lno.70101", "accessDate": "2025-06-24T14:59:50Z", "PMID": "", "PMCID": "", "ISSN": "1939-5590", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "© 2025 Association for the Sciences of Limnology and Oceanography.", "extra": "https://doi.org/10.6073/pasta/5b5424f8650a5fc182fd4c10849a636e\nhttps://doi.org/10.6073/pasta/755d4a016fcc053c6dcd816be97d0e7e\nhttps://doi.org/10.6073/pasta/91eec1c3e67f7cdbacc4629523984b99\nhttps://doi.org/10.6073/pasta/71fe332b9971fc53e151ce4591e94107\nhttps://doi.org/10.6073/pasta/8bdd243898587942f5b59e4132b65c19\nhttps://doi.org/10.6073/pasta/c938e9fa324f80cf9307c9e616b0ad6e\nhttps://doi.org/10.6073/pasta/bb99f1d4a7aeeac1ca64096747213876", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2025-06-24T14:59:50Z", "dateModified": "2025-09-17T18:02:52Z" } }, { "key": "TH7BXDP9", "version": 790, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/TH7BXDP9", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/TH7BXDP9", "type": "text/html" } }, "meta": { "createdByUser": { "id": 5767825, "username": "atn38", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/atn38", "type": "text/html" } } }, "lastModifiedByUser": { "id": 5056957, "username": "BLE-IM", "name": "Tim Whiteaker", "links": { "alternate": { "href": "https://www.zotero.org/ble-im", "type": "text/html" } } }, "creatorSummary": "Rawlins", "parsedDate": "2021-10", "numChildren": 0 }, "data": { "key": "TH7BXDP9", "version": 790, "itemType": "journalArticle", "title": "Increasing freshwater and dissolved organic carbon flows to Northwest Alaska's Elson lagoon", "creators": [ { "creatorType": "author", "firstName": "Michael A.", "lastName": "Rawlins" } ], "abstractNote": "", "publicationTitle": "Environmental Research Letters", "publisher": "", "place": "", "date": "2021-10", "volume": "16", "issue": "10", "section": "", "partNumber": "", "partTitle": "", "pages": "105014", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Environ. Res. Lett.", "DOI": "10.1088/1748-9326/ac2288", "citationKey": "", "url": "https://doi.org/10.1088/1748-9326/ac2288", "accessDate": "2021-10-13T20:39:11Z", "PMID": "", "PMCID": "", "ISSN": "1748-9326", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Institute of Physics", "callNumber": "", "rights": "", "extra": "https://doi.org/10.6073/pasta/a49b3da18b4c83d6ff69d9d878bb7dc3", "tags": [ { "tag": "LTER-BLE" }, { "tag": "LTER-Funded" }, { "tag": "Supported" } ], "collections": [ "8BH9MRG3", "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2021-10-13T20:39:11Z", "dateModified": "2025-06-24T15:02:07Z" } }, { "key": "L3SJVYBU", "version": 789, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/L3SJVYBU", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/L3SJVYBU", "type": "text/html" } }, "meta": { "createdByUser": { "id": 5056957, "username": "BLE-IM", "name": "Tim Whiteaker", "links": { "alternate": { "href": "https://www.zotero.org/ble-im", "type": "text/html" } } }, "creatorSummary": "von Biela et al.", "parsedDate": "2022-12-24", "numChildren": 0 }, "data": { "key": "L3SJVYBU", "version": 789, "itemType": "journalArticle", "title": "Borealization of nearshore fishes on an interior Arctic shelf over multiple decades", "creators": [ { "creatorType": "author", "firstName": "Vanessa R.", "lastName": "von Biela" }, { "creatorType": "author", "firstName": "Sarah M.", "lastName": "Laske" }, { "creatorType": "author", "firstName": "Ashley E.", "lastName": "Stanek" }, { "creatorType": "author", "firstName": "Randy J.", "lastName": "Brown" }, { "creatorType": "author", "firstName": "Kenneth H.", "lastName": "Dunton" } ], "abstractNote": "", "publicationTitle": "Global Change Biology", "publisher": "", "place": "", "date": "12/24/2022", "volume": "", "issue": "", "section": "", "partNumber": "", "partTitle": "", "pages": "", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1111/gcb.16576", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.16576", "accessDate": "2023-01-23T18:48:30Z", "PMID": "", "PMCID": "", "ISSN": "1365-2486", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "", "extra": "_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.16576", "tags": [ { "tag": "Alaska", "type": 1 }, { "tag": "Arctic", "type": 1 }, { "tag": "Beaufort Sea", "type": 1 }, { "tag": "Dolly Varden", "type": 1 }, { "tag": "LTER-BLE" }, { "tag": "LTER-Enabled" }, { "tag": "Supported" }, { "tag": "borealization", "type": 1 }, { "tag": "community reorganization", "type": 1 }, { "tag": "fourhorn sculpin", "type": 1 }, { "tag": "saffron cod", "type": 1 }, { "tag": "warming climate", "type": 1 } ], "collections": [ "IJ4K8DFH", "JK9MDZ2M", "KHTHLKB5" ], "relations": {}, "dateAdded": "2023-01-23T18:48:30Z", "dateModified": "2025-06-24T15:01:19Z" } }, { "key": "GLT6RI3I", "version": 785, "library": { "type": "group", "id": 2211939, "name": "LTER-BLE", "links": { "alternate": { "href": "https://www.zotero.org/groups/lter-ble", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/2211939/items/GLT6RI3I", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/lter-ble/items/GLT6RI3I", "type": "text/html" } }, "meta": { "createdByUser": { "id": 5056957, "username": "BLE-IM", "name": "Tim Whiteaker", "links": { "alternate": { "href": "https://www.zotero.org/ble-im", "type": "text/html" } } }, "creatorSummary": "Spera and Lougheed", "parsedDate": "2025", "numChildren": 1 }, "data": { "key": "GLT6RI3I", "version": 785, "itemType": "journalArticle", "title": "CO2 Emissions From Low Order Tundra Streams Stimulated by Surface-Subsurface Connectivity Following Extreme Rainfall Events", "creators": [ { "creatorType": "author", "firstName": "Alina C.", "lastName": "Spera" }, { "creatorType": "author", "firstName": "Vanessa L.", "lastName": "Lougheed" } ], "abstractNote": "Increases to summer Arctic rainfall and tundra thermal degradation are altering hydrological cycling in coastal watersheds with implications for carbon (C) cycling and transport of C to the atmosphere and coast. Arctic riverine research has focused on large rivers; however, small streams contribute significantly to vertical and longitudinal carbon dioxide (CO2) fluxes. Despite the well-established connection between hydrology and biogeochemistry, the impact of extreme rainfall events on Arctic aquatic C cycling remains a knowledge gap. This study characterized how hydrology, biogeochemistry, and geomorphology control the supply of CO2 to low order streams and their propensity to act as atmospheric CO2 sources. We characterize biogeochemical and hydrologic processes in unique reaches from a beaded stream and stream impacted by thermal erosion. Rainfall and its resulting increases to terrestrial-aquatic connectivity drove the movement of CO2 and biodegradable dissolved organic C (BDOC) from soils into streams, however, BDOC mineralization only contributed a small portion of surface CO2 fluxes. Rain events likely stimulated stream benthic respiration, which led to CO2 contributions from net ecosystem production often exceeding surface CO2 fluxes and downstream CO2 transport. In addition, thermal degradation played a role in terrestrial-aquatic connectivity of the streams. The erosion-affected stream had inconsistent and smaller inputs of CO2, had weaker heterotrophic conditions, and smaller CO2 emissions. Understanding how hydrologic regime, influenced by late summer rain events and stream morphology, controls the transport of CO2 and metabolism in small tundra streams will help improve predictions of landscape scale CO2 emissions from these critically understudied systems.", "publicationTitle": "Journal of Geophysical Research: Biogeosciences", "publisher": "", "place": "", "date": "2025", "volume": "130", "issue": "5", "section": "", "partNumber": "", "partTitle": "", "pages": "e2024JG008459", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1029/2024JG008459", "citationKey": "", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1029/2024JG008459", "accessDate": "2025-06-03T18:35:48Z", "PMID": "", "PMCID": "", "ISSN": "2169-8961", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "en", "libraryCatalog": "Wiley Online Library", "callNumber": "", "rights": "© 2025. American Geophysical Union. All Rights Reserved.", "extra": "https://doi.org/10.6073/pasta/eb56765417b7156cb178c73d963c7283", "tags": [ { "tag": "LTER-BLE" }, { "tag": "Supported" }, { "tag": "carbon dioxide", "type": 1 }, { "tag": "hydrology", "type": 1 }, { "tag": "metabolism", "type": 1 }, { "tag": "thermokarst", "type": 1 }, { "tag": "tundra stream", "type": 1 } ], "collections": [ "IJ4K8DFH", "KHTHLKB5" ], "relations": {}, "dateAdded": "2025-06-03T18:35:48Z", "dateModified": "2025-06-03T18:40:27Z" } } ]