Article Remote Sensing of Coastal Upwelling in the South-Eastern Baltic Sea: Statistical Properties and Implications for the Coastal Environment Toma Dabuleviciene 1,2,*, Igor E. Kozlov 1,2,3, Diana Vaiciute 1,2 and Inga Dailidiene 1 1 Natural Sciences Department, Klaipeda University, Herkaus Manto str. 84, LT-92294, Klaipeda, Lithuania;
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[email protected] (I.D.) 2 Marine Research Institute, Klaipeda University, Universiteto ave. 17, LT-92294, Klaipeda, Lithuania 3 Satellite Oceanography Laboratory, Russian State Hydrometeorological University, Malookhtinsky Prosp., 98, 195196 Saint Petersburg, Russia * Correspondence:
[email protected]; Tel.: +370-6516-1459 Received: 14 September 2018; Accepted: 3 November 2018; Published: 6 November 2018 Abstract: A detailed study of wind-induced coastal upwelling (CU) in the south-eastern Baltic Sea is presented based on an analysis of multi-mission satellite data. Analysis of moderate resolution imaging spectroradiometer (MODIS) sea surface temperature (SST) maps acquired between April and September of 2000–2015 allowed for the identification of 69 CU events. The Ekman-based upwelling index (UI) was applied to evaluate the effectiveness of the satellite measurements for upwelling detection. It was found that satellite data enable the identification of 87% of UI-based upwelling events during May–August, hence, serving as an effective tool for CU detection in the Baltic Sea under relatively cloud-free summer conditions. It was also shown that upwelling-induced SST drops, and its spatial properties are larger than previously registered. During extreme upwelling events, an SST drop might reach 14 °C, covering a total area of nearly 16,000 km2.