INVESTIGATION HYDROMETEOROLOGICAL REGIME OF THE WHITE SEA BASED ON SATELLITE ALTIMETRY DATA Sergey A. Lebedev (1, 2) (1) Geophysical Center of the Russian Academy of Sciences, 3, Molodezhnaya Str., Moscow, 119296, Russian, Email: lebedev@wdcb.ru (2) Space Research Institute of the Russian Academy of Sciences, 84/32, Profsoyuznaya Str, Moscow, 117997, Russia, Email: sergey_a_lebedev@mail.ru ABSTRACT The White Sea are the seas of the Arctic Ocean. Today complicated hydrodynamic, tidal, ice, and meteorological regimes of these seas may be investigated on the basis of remote sensing data, specifically of satellite altimetry data. Results of calibration and validation of satellite altimetry measurements (sea surface height and sea surface wind speed) and comparison with regional tidal model show that this type of data may be successfully used in scientific research and in monitoring of the environment. Complex analysis of the tidal regime of the White Sea and comparison between global and regional tidal models show advantages of regional tidal model for use in tidal correction of satellite altimetry data. Examples of using the sea level data in studying long-term variability of the Barents and White Seas are presented. Interannual variability of sea ice edge position is estimated on the basis of altimetry data. 1. INTRODUCTION The White Sea is a semi-enclosed inland sea (Fig. 1). The sea border with the Barents Sea is a line joining Cape Svyatoy Nos (northeastern coast of Kola Peninsula) with Cape Kanin Nos (northwestern extremity of Kanin Peninsula). The northern part of the sea is called the Voronka (funnel). The southern and central parts of the White Sea called the Basin are the largest and deepest parts of the sea. There are also several large and shallow bays in the area, namely the Dvinsky, Onega, Mezen, and Kandalaksha bays. The Gorlo (neck) is a narrow strait connecting the Basin and Voronka. The total water surface area is 90,873 km 2 including islands, and the total volume is 6,000 km 3 including also the Voronka area opening to the Barents Sea. Thus, the White Sea covers approximately 6% of the total open water area of both seas and comprises only 2% of the total volume of marine water, but it assumes more than half of the river runoff in the region. The White Sea watershed area is 729,000 km 2 [1]. The total river runoff is 259 km 3 /year, which is about 4% of the total amount of the White Sea water volume. The main rivers are the Severnaya Dvina, Onega, and Mezen having runoff of 111, 18, and 26 km 3 /year correspondingly [2−3]. In the White Sea, winds from the south, southwest, and west prevail from October to Figure 1. Maps of the White Sea. Dashed lines show boundaries of the seas and their internal parts. Circles mark tide gauges location [4]. March, whereas in May–August winds from north, northeast, and east are most frequent [2]. Southeasterly winds are frequently observed at the top of the bays (in ports Mezen, Kandalaksha, Onega). Monthly mean wind speed in the open sea and on islands is 7–10 m/s from September to April and 5–7 m/s from May to August. In the bays running deeply on land side, mean wind speed does not exceed 3–5 m/s during the whole year. The general circulation and sea level variations in the Barents and White seas are formed under cumulative effect of wind forcing, water interaction, and exchanges among surrounding seas, strong tides, peculiarities of bottom topography, seasonal variability of river runoff, precipitation and ice cover, and other factors. Thus, sea level variations in the Barents and White seas have a complex nature and are characterized by a significant spatial and temporal variability. The seasonal variations of the sea level in the Barents and White seas are caused by an impact of atmospheric pressure and wind, temperature and salinity, river runoff, precipitation, and ice cover [3]. A range of seasonal variations in the White Sea level are observed in the estuary zones of the Onega and Severnaya Dvina rivers and may reach 30–60 cm [3, 5]. 35° 40° 45° 64° 66° 68° Kola Peninsula Kan i n Peninsu la Cape Kanin Nos Cape Svyatoy Nos Mozhovets Is. Solovetsky Islands Voronka Gorlo Basin Mezen Bay Dvinsky Bay Kandalaksha Bay Onega Bay Mezen River Severnaya Dvina River Onega River Sosnovets Severodvinsk Bakaritsa Onega Kem’ Port Solovki Umba Kandalaksha _____________________________________ Proc. ‘Living Planet Symposium 2016’, Prague, Czech Republic, 9–13 May 2016 (ESA SP-740, August 2016)