{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T08:58:54Z","timestamp":1774601934006,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2023,12,13]],"date-time":"2023-12-13T00:00:00Z","timestamp":1702425600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science Foundation","award":["OCE 2123128"],"award-info":[{"award-number":["OCE 2123128"]}]},{"name":"National Science Foundation","award":["OCE 1756361"],"award-info":[{"award-number":["OCE 1756361"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>In the 2010s, a large freshening event similar to past Great Salinity Anomalies occurred in the Iceland Basin that has since propagated into the Irminger Sea. The source waters of this fresh anomaly were hypothesized to have come from an eastward diversion of the Labrador Current, a finding that has since been supported by recent modeling studies. In this study, we investigate the pathways of the freshwater anomaly using a purely observational approach: particle tracking using satellite altimetry-derived surface velocity fields. Particle trajectories originating in the Labrador Current and integrated forward in time entered the Iceland Basin during the freshening event at nearly twice the frequency observed prior to 2009, suggesting an increased presence of Labrador Current-origin water in the Iceland Basin and Rockall Trough during the freshening. We observe a distinct regime change in 2009, similar to the timing found in the previous modeling papers. These spatial shifts were accompanied by faster transit times along the pathways which led to along-stream convergence and more particles arriving to the eastern subpolar gyre. These findings support the hypothesis that a diversion of relatively fresh Labrador Current waters eastward from the Grand Banks can explain the unprecedented freshening in the Iceland Basin.<\/jats:p>","DOI":"10.3390\/rs15245711","type":"journal-article","created":{"date-parts":[[2023,12,13]],"date-time":"2023-12-13T08:55:16Z","timestamp":1702457716000},"page":"5711","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Investigation of the Source of Iceland Basin Freshening: Virtual Particle Tracking with Satellite-Derived Geostrophic Surface Velocities"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2554-8681","authenticated-orcid":false,"given":"Heather H.","family":"Furey","sequence":"first","affiliation":[{"name":"Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1450-8852","authenticated-orcid":false,"given":"Nicholas P.","family":"Foukal","sequence":"additional","affiliation":[{"name":"Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA"}]},{"given":"Adele","family":"Anderson","sequence":"additional","affiliation":[{"name":"Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0902-4984","authenticated-orcid":false,"given":"Amy S.","family":"Bower","sequence":"additional","affiliation":[{"name":"Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6743","DOI":"10.1175\/JCLI-D-11-00549.1","article-title":"Mechanisms behind the temporary shutdown of deep convection in the Labrador Sea: Lessons from the Great Salinity Anomaly Years 1968\u20131971","volume":"25","author":"Gelderloos","year":"2012","journal-title":"J. Clim."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1038\/ngeo2740","article-title":"Emerging impact of Greenland meltwater on deepwater formation in the North Atlantic Ocean","volume":"9","author":"Behrens","year":"2016","journal-title":"Nat. Geosci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"10525","DOI":"10.1038\/ncomms10525","article-title":"Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation","volume":"7","author":"Yang","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1038\/s41467-020-14474-y","article-title":"Ocean Circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic","volume":"11","author":"Holliday","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e2022GL098857","DOI":"10.1029\/2022GL098857","article-title":"Arrival of new great salinity anomaly weakens convection in the Irminger Sea","volume":"49","author":"Straneo","year":"2022","journal-title":"Geophys. Res. Lett."},{"key":"ref_6","first-page":"3","article-title":"Rapid export of waters formed by convection near the Irminger Sea\u2019s western boundary","volume":"47","author":"Straneo","year":"2020","journal-title":"Geophys. Res. Lett."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/0079-6611(88)90049-3","article-title":"The \u201cGreat Salinity Anomaly\u201d in the Northern North Atlantic 1968\u201382","volume":"20","author":"Dickson","year":"1988","journal-title":"Prog. Oceanogr."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0079-6611(98)00015-9","article-title":"\u201cGreat Salinity Anomalies\u201d in the North Atlantic","volume":"41","author":"Belkin","year":"1998","journal-title":"Prog. Oceanogr."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"L08306","DOI":"10.1029\/2003GL019334","article-title":"Propagation of the \u201cGreat Salinity Anomaly\u201d of the 1990s around the northern North Atlantic","volume":"31","author":"Belkin","year":"2004","journal-title":"Geophys. Res. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1080\/07055900.1980.9649089","article-title":"Oceanographic conditions at ocean weather ship Bravo, 1964\u20131974","volume":"18","author":"Lazier","year":"1980","journal-title":"Atmos.-Ocean"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1029\/2003GL017065","article-title":"Formation and propagation of great salinity anomalies","volume":"30","author":"Haak","year":"2003","journal-title":"Geophys. Res. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1029\/2007GL032675","article-title":"Reversal of the 1960s to 1990s freshening trend in the northeast North Atlantic and Nordic Seas","volume":"35","author":"Holliday","year":"2008","journal-title":"Geophys. Res. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2509","DOI":"10.1175\/JPO3123.1","article-title":"The western North Atlantic shelfbreak current system in summer","volume":"37","author":"Fratantoni","year":"2007","journal-title":"J. Phys. Oceanogr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"101505","DOI":"10.1016\/j.ocemod.2019.101505","article-title":"Ocean climate variability off Newfoundland and Labrador over 1979\u20132010: A modelling approach","volume":"144","author":"Han","year":"2019","journal-title":"Ocean Model."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.dsr.2009.11.006","article-title":"Freshwater export from the Labrador Current to the North Atlantic Current at the Tail of the Grand Banks of Newfoundland","volume":"57","author":"Fratantoni","year":"2009","journal-title":"Deep-Sea Res. I."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.ocemod.2015.12.009","article-title":"An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part II: Liquid freshwater","volume":"99","author":"Wang","year":"2016","journal-title":"Ocean Model."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1038\/s43247-021-00143-5","article-title":"Changes in the Gulf Stream preceded rapid warming of the Northwest Atlantic Shelf","volume":"2","author":"Langan","year":"2021","journal-title":"Commun. Earth Environ."},{"key":"ref_18","first-page":"3","article-title":"Temporal variability of the Labrador Current pathways around the Tail of the Grand Banks at intermediate depths in a high-resolution ocean circulation model","volume":"128","author":"Palter","year":"2023","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1507","DOI":"10.5194\/os-18-1507-2022","article-title":"Exceptional freshening and coolingin the eastern subpolar North Atlantic caused by reduced Labrador Sea surface heat loss","volume":"18","author":"Fox","year":"2022","journal-title":"Ocean Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1177","DOI":"10.5194\/os-17-1177-2021","article-title":"Regional imprints of changes in the Atlantic Meridional Overturning Circulation in the eddy-rich ocean model VIKING20x","volume":"17","author":"Biastoch","year":"2021","journal-title":"Ocean Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2623","DOI":"10.1038\/s41467-023-38321-y","article-title":"Large-scale control of the retroflection of the Labrador Current","volume":"14","author":"Jutras","year":"2023","journal-title":"Nat. Commun."},{"key":"ref_22","unstructured":"Reagan, J.R., and US DOC\/NOAA\/NESDIS\/NCEI > Oceanographic and Geophysical Science and Services Division (2023, July 05). World Ocean Atlas 2023\u2014Objectively Analyzed In Situ Temperature and Salinity Climatologies for the 1991\u20132020 Climate Normal Period (NCEI Accession 0270533). Subset 1991\u20132000 Climatology. NOAA National Centers for Environmental Information. Available online: https:\/\/www.ncei.noaa.gov\/archive\/accession\/0270533."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1002\/2014GL061773","article-title":"Beyond GOCE for the ocean circulation estimate: Synergistic use of altimetry, gravimetr, and in situ data provides new insight into geostrophic and Ekman currents","volume":"41","author":"Rio","year":"2014","journal-title":"Geophys. Res. Lett."},{"key":"ref_24","unstructured":"Cyr, F., Snook, S., Bishop, C., Galbraith, P.S., Chen, N., and Han, G. (2022). Physical Oceanographic Conditions on the Newfoundland and Labrador Shelf during 2021. DFO Can. Sci. Advis. Secr. Res. Doc., Available online: https:\/\/waves-vagues.dfo-mpo.gc.ca\/library-bibliotheque\/41063491.pdf."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"8849","DOI":"10.1175\/JCLI-D-19-0083.1","article-title":"Arctic Ocean and Hudson Bay freshwater exports: New estimates from seven decades of hydrographic surveys on the Labrador Shelf","volume":"33","author":"Bacon","year":"2020","journal-title":"J. Clim."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3571","DOI":"10.5194\/gmd-12-3571-2019","article-title":"The Parcels v2.0 Lagrangian framework: New field interpolation schemes","volume":"12","author":"Delandmeter","year":"2019","journal-title":"Geosci. Model Dev."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.1175\/JPO-D-18-0152.1","article-title":"Can Lagrangian tracking simulate tracer spreading in a high-resolution ocean general circulation model?","volume":"49","author":"Wagner","year":"2019","journal-title":"J. Phys. Oceanogr."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1067","DOI":"10.5194\/os-17-1067-2021","article-title":"Characteristics and robustness of Agulhas leakage estimates: An inter-comparison study of Lagrangian methods","volume":"17","author":"Schmidt","year":"2021","journal-title":"Ocean Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1038\/s43247-021-00120-y","article-title":"A shift in the ocean circulation has warmed the subpolar North Atlantic Ocean since 2016","volume":"2","author":"Chafik","year":"2021","journal-title":"Commun. Earth Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"C7","DOI":"10.1029\/2005JC003146","article-title":"Surface drifter exchange between the North Atlantic subtropical and subpolar gyres","volume":"111","author":"Brambilla","year":"2006","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1126\/science.1094917","article-title":"Decline of subpolar North Atlantic circulation during the 1990s","volume":"304","author":"Hakkinen","year":"2004","journal-title":"Science"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5945","DOI":"10.1002\/2015JC010762","article-title":"Multidecadal variability of potential temperature, salinity and transports in the eastern subpolar North Atlantic","volume":"120","author":"Holliday","year":"2015","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1029\/2022GL100989","article-title":"North Atlantic Ocean Circulation and Related Exchange of Heat and Salt Between Water Masses","volume":"50","author":"Berglund","year":"2023","journal-title":"Geophys. Res. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1002\/2017JC012798","article-title":"Assessing variability in the size and strength of the North Atlantic subpolar gyre","volume":"122","author":"Foukal","year":"2017","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1029\/2021JC018233","article-title":"Increasing frequency of salinity maximum intrusions in the Middle Atlantic Bight","volume":"127","author":"Gawarkiewicz","year":"2022","journal-title":"J. Geophys. Res. Ocean."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/24\/5711\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:37:59Z","timestamp":1760132279000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/24\/5711"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,12,13]]},"references-count":35,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["rs15245711"],"URL":"https:\/\/doi.org\/10.3390\/rs15245711","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,12,13]]}}}