Spatial variations in sea-ice formation-onset in the Laptev Sea as a Consequence of the vertical heat fluxes caused by internal waves overturning

• Main Author: Kirillov, Sergey
• Format: Article in Journal/Newspaper
• Language: English
• Published: Deutsche Gesellschaft für Polarforschung 2007
• Subjects: Laptev Sea; laptev; lena river; Polarforschung; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/28498/; https://oceanrep.geomar.de/id/eprint/28498/1/Kirillov_2007_Polarforschung_Spatial_Variations.pdf; http://epic.awi.de/28582/1/Polarforsch2006_3_4.pdf

The Laptev Sea shelf is an area that is strongly affected by the continental runoff in the summer. Huge amount of freshwater flows into the eastern Laptev Sea via the Lena River and forms a density interface that strongly affects the water column dynamics and the thermal processes. Delay in ice formation might be one of the consequences caused by both density stratification and the solar heat accumulated in the deeper layer. The internal waves seem to be one of the possible mechanisms that cause the mixing and explain the observed variations in ice-formation dates. Data of several ADCP records deployed in the Laptev Sea in 1998/1999 and 2000 were processed in an attempt to evaluate the heat exchange rate due to the internal wave acting. It was found that vertical heat flux could result in an additional delay of ice-formation up to 5-6 days depending on the local bottom topography. It was also revealed that the storm events in fall increase the average energy of internal wave spectrum by 2-3 times over its calm state. This can also enhance the efficiency of exchange through the pycnocline by the factor of 5-10.