Modification of Pacific water in the northern Canadian Arctic
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Modification of Pacific water in the northern Canadian Arctic. / Dmitrenko, Igor A.; Kirillov, Sergei A.; Rudels, Bert; Geilfus, Nicolas Xavier; Ehn, Jens; Babb, David G.; Lilien, David A.; Dahl-Jensen, Dorthe.
I: Frontiers in Marine Science, Bind 10, 1181800, 12.06.2023.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Modification of Pacific water in the northern Canadian Arctic
AU - Dmitrenko, Igor A.
AU - Kirillov, Sergei A.
AU - Rudels, Bert
AU - Geilfus, Nicolas Xavier
AU - Ehn, Jens
AU - Babb, David G.
AU - Lilien, David A.
AU - Dahl-Jensen, Dorthe
N1 - Publisher Copyright: Copyright © 2023 Dmitrenko, Kirillov, Rudels, Geilfus, Ehn, Babb, Lilien and Dahl-Jensen.
PY - 2023/6/12
Y1 - 2023/6/12
N2 - The oceanography of the northern Canadian Arctic Archipelago (CAA) remains poorly studied. Here we present a unique set of conductivity–temperature–depth (CTD) and nitrate profiles collected in a fjord system around Axel Heiberg Island in the northern CAA during April–May 2022. The profiles are examined within the context of upstream observations in the Arctic Ocean and downstream observations in the central CAA, and reveal the origin of water masses and their interactions with ambient water from the continental slope and the nearby tidewater glacier outlet. The subsurface water (~25–180 m depth) is associated with the Pacific water outflow from the Arctic Ocean. The underlying halocline separates Pacific water from a deeper layer of polar water that has interacted with the warm (>0°C) Atlantic water observed below 240 m depth. Pacific water is significantly modified compared to the adjoining Arctic Ocean, as evidenced by the following details. Cold water intrusions from the tidewater glacier create deviations of ~0.25°C in the temperature profile through the subsurface water down to a depth of 140 m. Profiles show no thermal signature of Pacific summer water. Compared to the adjacent Arctic Ocean, the deeper fraction of Pacific-derived water and the Atlantic-modified polar water are warmer, while the underlying Atlantic water is colder. Overall, our results suggest that Pacific and Atlantic water in this area of the northern CAA are modified due to enhanced vertical mixing in a narrow band over the continental slope and shelf off the CAA, and are further modified by interactions with outlet glaciers in the area. This implies that tracing the initial thermohaline signature of the Pacific and Atlantic water flow through the CAA seems to be hardly possible without the use of additional tracers. We also find evidence of geothermal heating near the seafloor, which is not surprising given the observed presence of terrestrial geothermal vents around Axel Heiberg Island, and speculate this heat flux limits ice growth near the glacier terminus.
AB - The oceanography of the northern Canadian Arctic Archipelago (CAA) remains poorly studied. Here we present a unique set of conductivity–temperature–depth (CTD) and nitrate profiles collected in a fjord system around Axel Heiberg Island in the northern CAA during April–May 2022. The profiles are examined within the context of upstream observations in the Arctic Ocean and downstream observations in the central CAA, and reveal the origin of water masses and their interactions with ambient water from the continental slope and the nearby tidewater glacier outlet. The subsurface water (~25–180 m depth) is associated with the Pacific water outflow from the Arctic Ocean. The underlying halocline separates Pacific water from a deeper layer of polar water that has interacted with the warm (>0°C) Atlantic water observed below 240 m depth. Pacific water is significantly modified compared to the adjoining Arctic Ocean, as evidenced by the following details. Cold water intrusions from the tidewater glacier create deviations of ~0.25°C in the temperature profile through the subsurface water down to a depth of 140 m. Profiles show no thermal signature of Pacific summer water. Compared to the adjacent Arctic Ocean, the deeper fraction of Pacific-derived water and the Atlantic-modified polar water are warmer, while the underlying Atlantic water is colder. Overall, our results suggest that Pacific and Atlantic water in this area of the northern CAA are modified due to enhanced vertical mixing in a narrow band over the continental slope and shelf off the CAA, and are further modified by interactions with outlet glaciers in the area. This implies that tracing the initial thermohaline signature of the Pacific and Atlantic water flow through the CAA seems to be hardly possible without the use of additional tracers. We also find evidence of geothermal heating near the seafloor, which is not surprising given the observed presence of terrestrial geothermal vents around Axel Heiberg Island, and speculate this heat flux limits ice growth near the glacier terminus.
KW - Atlantic water
KW - Canadian Arctic Archipelago
KW - ocean-glacier interaction
KW - Pacific-derived water
KW - vertical mixing
U2 - 10.3389/fmars.2023.1181800
DO - 10.3389/fmars.2023.1181800
M3 - Journal article
AN - SCOPUS:85163614873
VL - 10
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
SN - 2296-7745
M1 - 1181800
ER -
ID: 360693639