The influence of ocean heat transport in the Barents Sea on the regional sea ice and the atmospheric static stability

M G Akperov,D D Bokuchava,I I Mokhov,W Dorn,V A Semenov,A Rinke,M A Dembitskaya

doi:10.15356/2076-6734-2019-4-417

Abstract

The influence of the oceanic heat inflow into the Barents Sea on the sea ice concentration and atmospheric characteristics, including the atmospheric static stability during winter months, is investigated on the basis of the results of ensemble simulations with the regional climate model HIRHAM/NAOSIM for the Arctic. The static stability of the atmosphere is the important indicator of the spatial and temporal variability of polar mesocyclones in the Arctic region. The results of the HIRHAM/NAOSIM regional climate model ensemble simulations (RCM) for the period from 1979 to 2016 were used for the analysis. The initial and lateral boundary conditions for RCM in the atmosphere were set in accordance with the ERA-Interim reanalysis data. An analysis of 10 ensemble simulations with identical boundary conditions and the same radiation forcing for the Arctic was performed. Various realizations of ensemble simulations with RCM were obtained by changing the initial conditions for integrating the oceanic block of the model. Different realizations of ensemble simulations with RCM are obtained by changing the initial conditions of the model oceanic block integration. The composites method was used for the analysis, i.e. the difference between the mean values for years with the maximum and minimum inflow of oceanic water into the Barents Sea. The statistical significance of the results (at a significance level of p < 0.05) was estimated using Student's t-test. In general, the regional climate model reproduces the seasonal changes in the inflow of the oceanic water and heat into the Barents Sea reasonably well. There is a strong relationship between the changes in the oceanic water and ocean heat inflow, sea ice concentration, and surface air temperature in the Barents Sea. Herewith, the increase in the oceanic water inflow into the Barents Sea in winter leads to a decrease in static stability, which contributes to changes in regional cyclonic activity. The decrease of the static stability is most pronounced in the southern part of the Barents Sea and also to the west of Svalbard.

Highlights

Ключевые слова: Баренцево море, изменения климата, морской лёд, полярные мезоциклоны, приток океанических вод, региональная модель климата, циклоны
Значимая роль притока тёплых океа нических вод в изменчивости приповерхностной температуры воздуха, площади морских льдов и региональной циркуляции в Баренцевом море отмечается во многих работах [2, 11, 18,19,20,21]
Данные ансамблевых расчётов с региональной климатической моделью показывают определя ющую роль вариаций притока океанических вод в Баренцево море в формировании изменчиво сти режима морских льдов и приповерхностной температуры воздуха

Summary

Introduction

Ключевые слова: Баренцево море, изменения климата, морской лёд, полярные мезоциклоны, приток океанических вод, региональная модель климата, циклоны. На основе результатов ансамблевых расчётов с использованием региональной климатической модели HIRHAM/NAOSIM для Арктики исследовано влияние притока океанических вод в Баренцево море на концентрацию морских льдов и характеристики атмосферы в зимние месяцы. Показана определяющая роль вариаций притока океанических вод в Баренцево море на режим морских льдов и приповерхностной температуры воздуха, а также статическую устойчивость атмосферы в зимний период.

Results

Conclusion