Heat, salt, and volume transports in the eastern Eurasian Basin of the Arctic Ocean from 2 years of mooring observations

• Published in: Ocean Science
• Main Authors: Pnyushkov, Andrey V., Polyakov, Igor V., Rember, Robert, Ivanov, Vladimir V., Alkire, Matthew B., Ashik, Igor M., Baumann, Till M., Alekseev, Genrikh V., Sundfjord, Arild
• Format: Text
• Language: English
• Published: 2018
• Subjects: Arctic; Arctic Ocean; Laptev Sea; laptev
• Online Access: https://doi.org/10.5194/os-14-1349-2018; https://os.copernicus.org/articles/14/1349/2018/

This study discusses along-slope volume, heat, and salt transports derived from observations collected in 2013–2015 using a cross-slope array of six moorings ranging from 250 to 3900 m in the eastern Eurasian Basin (EB) of the Arctic Ocean. These observations demonstrate that in the upper 780 m layer, the along-slope boundary current advected, on average, 5.1±0.1 Sv of water, predominantly in the eastward (shallow-to-right) direction. Monthly net volume transports across the Laptev Sea slope vary widely, from <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mn mathvariant="normal">0.3</mn><mo>±</mo><mn mathvariant="normal">0.8</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="54pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="ce0352cb99ace134c91fc8ed9607d24f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-14-1349-2018-ie00001.svg" width="54pt" height="10pt" src="os-14-1349-2018-ie00001.png"/></svg:svg> in April 2014 to <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mn mathvariant="normal">9.9</mn><mo>±</mo><mn mathvariant="normal">0.8</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="54pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="6b60514a27b9d442ef200248e4e5a41e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-14-1349-2018-ie00002.svg" width="54pt" height="10pt" src="os-14-1349-2018-ie00002.png"/></svg:svg> Sv in June 2014; 3.1±0.1 Sv (or 60 %) of the net transport was associated with warm and salty intermediate-depth Atlantic Water (AW). Calculated heat transport for 2013–2015 (relative to −1.8 ∘ C) was 46.0±1.7 TW, and net salt transport (relative to zero salinity) was 172±6 Mkg s −1 . Estimates for AW heat and salt transports were 32.7±1.3 TW (71 % of net heat transport) and 112±4 Mkg s −1 (65 % of net salt transport). The variability of currents explains ∼90 % of the variability in the heat and salt transports. The remaining ∼10 % is controlled by temperature and salinity anomalies together with the temporal variability of the AW layer thickness. The annual mean volume transports decreased by 25 % from 5.8±0.2 Sv in 2013–2014 to 4.4±0.2 Sv in 2014–2015, suggesting that changes in the transports at interannual and longer timescales in the eastern EB may be significant.