Extremely Strong Winds and Weather Patterns over Arctic seas

Abstract

Strong wind is the main cause of storm sea waves. In order to minimize risks and damages from this phenomenon in the future, precise projections of future climate conditions are necessary. Extremely high wind speed events in the 20th - 21st centuries over Arctic seas were investigated using ERA-Interim reanalysis data (1981-2010) and CMIP5 models ensemble (RCP8.5 scenario, 2005-2100). Two different approaches were applied to investigate extreme wind events. The first one is traditional and involves direct analysis of wind speed data. It was used for the entire area of the Arctic seas. The second approach is based on an assumption that local and mesoscale extreme weather events are connected with large-scale synoptic processes. As it was shown in previous studies for the Black, Caspian and Baltic seas, it is possible to make climate projection of sea storm waves indirectly, studying the heterogeneity of sea level atmospheric pressure (SLP) fields that are the main factors of strong wind speed and wind waves. In this case, it is not necessary to run long-term simulations with a sea wave model to predict storm activity for the future climate. It is possible to analyze projections of storm SLP fields that are predicted by climate models much better than the wind speed required for a wave model. This method was implemented for the high wind speed events over the Barents Sea. Four major types of SLP fields accompanying high wind speed were revealed for the modern climate. It was shown that the frequency of their occurrence is expected to increase by the end of the 21st century.

Keywords

• wind speed extremes
• global warming
• arctic
• weather patterns
• oceanatmosphere interaction