The Laptev Sea flaw polynya, Russian Arctic: effects on the mesoscale hydrography.

Dmitrenko, Igor, Hölemann, Jens A. , Tyshko, Konstantin, Churun, V., Kirillov, Sergey and Kassens, Heidemarie (2001) The Laptev Sea flaw polynya, Russian Arctic: effects on the mesoscale hydrography. Annals of Glaciology, 33 (1). pp. 373-376. DOI 10.3189/172756401781818455.

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Abstract

A detailed analysis of hydrographic data from a period of 20 years (1980 99) has shown that the persistent presence of a flaw polynya influences mesoscale hydrography of the Laptev Sea, Russian Arctic. Based on these data, the interannual variability of surface,water salinity within the polynya has been estimated. As the salinity increase in the water layer is mainly caused by the formation of new ice within the polynya, the average ice-production rate of the polynya was calculated. The results indicate all ice production of 3-4 in per season. further aim of this study was to calculate the probability that the convective mixing in the polynya penetrates to the sea-floor. It is demonstrated that the probability is maximal in the flaw-polynya area, but does not exceed 20% in the eastern and 70% in the western part of the polynya, as a result of strong vertical density stratification from river runoff, especially in the eastern Laptev Sea. Additional studies of water circulation in the marginal zone of the flaw polynya were carried out during field observations in April-May 1999. On the basis of conductivity-temperature-depth and current measurements we deduce that high current velocities (62 cm s(-1)) recorded in surface waters near the fast-ice edge are caused by a convectively driven circulation system under the polynya, Our measurements indicate that these high-velocity currents are part of a cellular circulation, which results from the rejection of brine during intensive ice formation in the polynya. The observed azimuthal alignment of the crystalline structure of sea ice is also, most probably, the consequence of this quasi-stationary, cellular circulation.

Document Type: Article
Additional Information: WOS:000173446300059
Keywords: Hydrography; Polynya; Leads; Ice; Export; Laptev Sea; Russian Arctic;
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-P-OZ Paleo-Oceanography
HGF-AWI
Refereed: Yes
Open Access Journal?: No
Publisher: International Glaciological Society
Projects: Laptev Sea System 2000
Date Deposited: 13 Jan 2015 12:48
Last Modified: 23 Sep 2019 21:18
URI: https://oceanrep.geomar.de/id/eprint/26934

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