Articles | Volume 8, issue 3
Research article
08 Aug 2017
Research article |  | 08 Aug 2017

Satellite altimetry reveals spatial patterns of variations in the Baltic Sea wave climate

Nadezhda Kudryavtseva and Tarmo Soomere

Abstract. The main properties of the climate of waves in the seasonally ice-covered Baltic Sea and its decadal changes since 1990 are estimated from satellite altimetry data. The data set of significant wave heights (SWHs) from all existing nine satellites, cleaned and cross-validated against in situ measurements, shows overall a very consistent picture. A comparison with visual observations shows a good correspondence with correlation coefficients of 0.6–0.8. The annual mean SWH reveals a tentative increase of 0.005 m yr−1, but higher quantiles behave in a cyclic manner with a timescale of 10–15 years. Changes in the basin-wide average SWH have a strong meridional pattern: an increase in the central and western parts of the sea and a decrease in the east. This pattern is likely caused by a rotation of wind directions rather than by an increase in the wind speed.

Short summary
We discuss for the first time changes in the wave climate in the Baltic Sea over the last 2 decades derived from satellite altimetry data spanning over 26 years. We found in the study that there are variations in the wave climate of the Baltic Sea, which can be interpreted as being caused predominantly by a rotation of wind direction rather than increased wind speed, implying that associated variations in the airflow direction can be a dominant driver of regional climate changes.
Final-revised paper