New Possibilities In The Study Of Coastal Upwellings In The Southeastern Baltic Sea With Using Thermistor Chain

摘要

The article gives an analysis of a unique data of the thermistor chain, whichinstalled on the D-6 oil platform in the coastal zone of the Baltic Sea. In total 10 temperaturesensors were installed at different depths with a recording interval of 1 min, the depth atthe installation site was 29 m. Based on satellite data, ship measurements and thermistorchain observation the characteristics and dynamics of the sharp decrease in watertemperature which registered in the south-eastern Baltic Sea (Gdansk Bay area), duringJune 5-12, 2016 are analyzed. The temperature decreasing caused by the simultaneousaction of at least two factors: wind-driven Ekman upwelling and advection of cold water.Scales of temporal and spatial variability of water temperature in a coastal zone of thesouth-eastern Baltic Sea near the coast of the Kaliningrad region are described. This eventled to the considerable SST (sea surface temperature) drop by more than 8 °C for twodays. The rate of reduction of its temperature during certain upwelling periods can reach0.3-0.4 oС per hour, but the maximum warming rate between phases varies from 0.25 to0.28 oС per hour. This dramatically changed the conditions of the thermal balance of thesea surface. The width of the upwelling, as seen in the SST data, was about 25 km. Satellitedata were supplemented with data of a thermistor chain and CTD measurements. Thehigh correlation between water temperature variability and changes in wind parameters:when the wind speed has decreased and its direction has changed, the response of thevertical thermal structure has occurred very quickly, sometimes within 1 hour. Thermistorchain data allow to evaluate the vertical temperature distribution and get more detailedanalysis of temporal variability and short pulsations of upwelling.