Connection between Eurasian and North Atlantic climate anomalies and natural variations in the Atlantic thermohaline circulation based on long-term model calculations

Abstract

We obtained estimates of the correlation between regional characteristics of the climate in Eurasia and the North Atlantic and the Atlantic thermohaline circulation (ATHC) based on the results of calculations using the ocean‐atmosphere global climate model (OAGCM) without external forcing (reference numerical experiment) for the period of 500 yr. The regions of statistically significant correlation between the ATHC variations in a few decades with the anomalies of surface air temperature, pressure at sea level, and precipitation in different seasons were distinguished. The most significant correlation was found in the winter period. A correlation was also found between the ATHC and the intensity of the Iceland minimum of the atmospheric action center (AC) [1], which has a strong influence on the weather conditions in Europe. The Atlantic thermohaline circulation, which shows a large-scale North Atlantic meridional overturning circulation (NAMOC) and represents a part of the global 3D oceanic current (conveyor belt) [2, 3], plays an important role in heat transfer to high latitudes of the Northern Hemisphere. The intensity of the ATHC shows strong long-period fluctuations accompanied by anomalies in the ocean surface temperature (OST) in the North Atlantic [4] and variations in the area of the Arctic ice cover [5]. This fact evidences the existence of