Investigation of the Barents Sea Upper Layer Response to the Polar Low in 1975

Abstract

The present paper is focused on reproducing the extreme polar low observed over the Barents Sea in early January 1975, on the metocean hindcast data and on analyzing the upper sea layer response to the cyclone passage. Methods and Results. All the calculations are carried out based on the Marine and Atmospheric Research System for simulating hydrometeorological characteristics of the western seas in the Russian Arctic (the Barents, White, Pechora and Kara seas). The main components of this system are the regional non-hydrostatic model of atmospheric circulation WRF (spatial resolution is 15 km) and the physically complete three-dimensional σ-model of marine circulation INMOM (spatial resolution is 2.7 km). The atmospheric reanalysis data and the results of previous studies are used. The polar low produced a severe impact on the central and eastern parts of the Barents Sea, namely, being strongly influenced by the storm winds, the near-surface current velocities changed significantly. During a storm period in these parts of the Barents Sea, the drift component prevails over the tidal one. The tidal component prevails in the shallow southern part of the Barents Sea even during the most extreme storm period. It is shown that a polar low can lead to increase of the sea surface temperature in the Barents Sea by more than 1°С. Conclusion. The sea surface temperature positive anomaly is formed by the dynamic processes associated with vertical mixing, upwelling in the western and central parts of the Barents Sea, the Ekman drift and downwelling near the Novaya Zemlya coast. Contribution of the sea-atmosphere heat exchange to formation of the surface temperature positive anomalies is negligible. On the contrary, in the southern part of the Barents Sea and in the Pechora Sea, a significant surface temperature decrease (by almost 1.5°С) is observed during a polar low passing. This is a result of the sea upper layer cooling due to the heat transfer from the sea surface to the atmosphere.

Sea surface temperature changes due to polar lows over the Nordic Seas

“…Также в работе (Isachsen et al, 2013) представлены измерения спутникового пассивного микроволнового радиометра Advanced Microwave Scanning Radiometer -Earth Observing System (AMSR-E) для одного случая полярного циклона, после прохождения которого в основной области воздействия циклона температура поверхности океана уменьшилась приблизительно на 1 °С, а в небольшом регионе увеличилась на 1 °С. Подобный результат получен и в работе (Diansky et al, 2019), где проведено численное моделирование интенсивного полярного циклона в январе 1975 г. и отклика верхнего слоя Баренцева моря на его прохождение и обнаружено уменьшение температуры поверхности в южной части моря почти на 1.5 °С и увеличение более чем на 1 °С в центральной и западной частях.…”