Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic
Isfjorden, a broad Arctic fjord in western Spitsbergen, has shown significant changes in hydrography and inflow of Atlantic Water (AW) the last decades that only recently have been observed in the Arctic Ocean north of Svalbard. Variability and trends in this fjord’s climate and circulation are ther...
Published in: | Progress in Oceanography |
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Online Access: | https://hdl.handle.net/11250/2738457 https://doi.org/10.1016/j.pocean.2020.102394 |
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ftunivbergen:oai:bora.uib.no:11250/2738457 2023-05-15T14:48:40+02:00 Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic Skogseth, Ragnheid Olivier, Léa L.A. Nilsen, Frank Falck, Eva Fraser, Neil J. Tverberg, Vigdis Ledang, Anna Birgitta Vader, Anna Jonassen, Marius Opsanger Søreide, Janne Cottier, Finlo Robert Berge, Jørgen Ivanov, Boris V. Falk-Petersen, Stig 2020 application/pdf https://hdl.handle.net/11250/2738457 https://doi.org/10.1016/j.pocean.2020.102394 eng eng Elsevier Norges forskningsråd: 222696 Norges forskningsråd: 227067 urn:issn:0079-6611 https://hdl.handle.net/11250/2738457 https://doi.org/10.1016/j.pocean.2020.102394 cristin:1820200 Progress in Oceanography. 2020, 187, 102394. Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright Crown Copyright 2020 102394 Progress in Oceanography 187 Journal article Peer reviewed 2020 ftunivbergen https://doi.org/10.1016/j.pocean.2020.102394 2023-03-14T17:43:30Z Isfjorden, a broad Arctic fjord in western Spitsbergen, has shown significant changes in hydrography and inflow of Atlantic Water (AW) the last decades that only recently have been observed in the Arctic Ocean north of Svalbard. Variability and trends in this fjord’s climate and circulation are therefore analysed from observational and reanalysis data during 1987 to 2017. Isfjorden experienced a shift in summer ocean structure in 2006, from AW generally in the bottom layer to AW (with increasing thickness) higher up in the water column. This shift, and a concomitant shift to less fast ice in Isfjorden are linked to positive trends in the mean sea surface temperature (SST) and volume weighted mean temperature (VT) in winter (SSTw/VTw: 0.7 ± 0.1/0.9 ± 0.3 °C 10 yr−1) and summer (SSTS/VTS: 0.7 ± 0.1/0.6 ± 0.1 °C 10 yr−1). Hence, the local mean air temperature shows similar trends in winter (1.9 ± 0.4 °C 10 yr−1) and summer (0.7 ± 0.1 °C 10 yr−1). Positive trends in volume weighted mean salinity in winter (0.21 ± 0.06 10 yr−1) and summer (0.07 ± 0.05 10 yr−1) suggest increased AW advection as a main reason for Isfjorden’s climate change. Local mean air temperature correlates significantly with sea ice cover, SST, and VT, revealing the fjord’s impact on the local terrestrial climate. In line with the shift in summer ocean structure, Isfjorden has changed from an Arctic type fjord dominated by Winter Deep and Winter Intermediate thermal and haline convection, to a fjord dominated by deep thermal convection of Atlantic type water (Winter Open). AW indexes for the mouth and Isfjorden proper show that AW influence has been common in winter over the last decade. Alternating occurrence of Arctic and Atlantic type water at the mouth mirrors the geostrophic control imposed by the Spitsbergen Polar Current (carrying Arctic Water) relative to the strength of the Spitsbergen Trough Current (carrying AW). During high AW impact events, Atlantic type water propagates into the fjord according to the cyclonic circulation along ... Article in Journal/Newspaper Arctic Arctic Ocean Climate change Isfjord* Isfjord* Isfjorden Isfjorden Sea ice Svalbard Spitsbergen University of Bergen: Bergen Open Research Archive (BORA-UiB) Arctic Arctic Ocean Spitsbergen Trough ENVELOPE(3.500,3.500,79.667,79.667) Svalbard Progress in Oceanography 187 102394 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
Isfjorden, a broad Arctic fjord in western Spitsbergen, has shown significant changes in hydrography and inflow of Atlantic Water (AW) the last decades that only recently have been observed in the Arctic Ocean north of Svalbard. Variability and trends in this fjord’s climate and circulation are therefore analysed from observational and reanalysis data during 1987 to 2017. Isfjorden experienced a shift in summer ocean structure in 2006, from AW generally in the bottom layer to AW (with increasing thickness) higher up in the water column. This shift, and a concomitant shift to less fast ice in Isfjorden are linked to positive trends in the mean sea surface temperature (SST) and volume weighted mean temperature (VT) in winter (SSTw/VTw: 0.7 ± 0.1/0.9 ± 0.3 °C 10 yr−1) and summer (SSTS/VTS: 0.7 ± 0.1/0.6 ± 0.1 °C 10 yr−1). Hence, the local mean air temperature shows similar trends in winter (1.9 ± 0.4 °C 10 yr−1) and summer (0.7 ± 0.1 °C 10 yr−1). Positive trends in volume weighted mean salinity in winter (0.21 ± 0.06 10 yr−1) and summer (0.07 ± 0.05 10 yr−1) suggest increased AW advection as a main reason for Isfjorden’s climate change. Local mean air temperature correlates significantly with sea ice cover, SST, and VT, revealing the fjord’s impact on the local terrestrial climate. In line with the shift in summer ocean structure, Isfjorden has changed from an Arctic type fjord dominated by Winter Deep and Winter Intermediate thermal and haline convection, to a fjord dominated by deep thermal convection of Atlantic type water (Winter Open). AW indexes for the mouth and Isfjorden proper show that AW influence has been common in winter over the last decade. Alternating occurrence of Arctic and Atlantic type water at the mouth mirrors the geostrophic control imposed by the Spitsbergen Polar Current (carrying Arctic Water) relative to the strength of the Spitsbergen Trough Current (carrying AW). During high AW impact events, Atlantic type water propagates into the fjord according to the cyclonic circulation along ... |
format |
Article in Journal/Newspaper |
author |
Skogseth, Ragnheid Olivier, Léa L.A. Nilsen, Frank Falck, Eva Fraser, Neil J. Tverberg, Vigdis Ledang, Anna Birgitta Vader, Anna Jonassen, Marius Opsanger Søreide, Janne Cottier, Finlo Robert Berge, Jørgen Ivanov, Boris V. Falk-Petersen, Stig |
spellingShingle |
Skogseth, Ragnheid Olivier, Léa L.A. Nilsen, Frank Falck, Eva Fraser, Neil J. Tverberg, Vigdis Ledang, Anna Birgitta Vader, Anna Jonassen, Marius Opsanger Søreide, Janne Cottier, Finlo Robert Berge, Jørgen Ivanov, Boris V. Falk-Petersen, Stig Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic |
author_facet |
Skogseth, Ragnheid Olivier, Léa L.A. Nilsen, Frank Falck, Eva Fraser, Neil J. Tverberg, Vigdis Ledang, Anna Birgitta Vader, Anna Jonassen, Marius Opsanger Søreide, Janne Cottier, Finlo Robert Berge, Jørgen Ivanov, Boris V. Falk-Petersen, Stig |
author_sort |
Skogseth, Ragnheid |
title |
Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic |
title_short |
Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic |
title_full |
Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic |
title_fullStr |
Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic |
title_full_unstemmed |
Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic |
title_sort |
variability and decadal trends in the isfjorden (svalbard) ocean climate and circulation – an indicator for climate change in the european arctic |
publisher |
Elsevier |
publishDate |
2020 |
url |
https://hdl.handle.net/11250/2738457 https://doi.org/10.1016/j.pocean.2020.102394 |
long_lat |
ENVELOPE(3.500,3.500,79.667,79.667) |
geographic |
Arctic Arctic Ocean Spitsbergen Trough Svalbard |
geographic_facet |
Arctic Arctic Ocean Spitsbergen Trough Svalbard |
genre |
Arctic Arctic Ocean Climate change Isfjord* Isfjord* Isfjorden Isfjorden Sea ice Svalbard Spitsbergen |
genre_facet |
Arctic Arctic Ocean Climate change Isfjord* Isfjord* Isfjorden Isfjorden Sea ice Svalbard Spitsbergen |
op_source |
102394 Progress in Oceanography 187 |
op_relation |
Norges forskningsråd: 222696 Norges forskningsråd: 227067 urn:issn:0079-6611 https://hdl.handle.net/11250/2738457 https://doi.org/10.1016/j.pocean.2020.102394 cristin:1820200 Progress in Oceanography. 2020, 187, 102394. |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright Crown Copyright 2020 |
op_doi |
https://doi.org/10.1016/j.pocean.2020.102394 |
container_title |
Progress in Oceanography |
container_volume |
187 |
container_start_page |
102394 |
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1766319763194118144 |