Impact of Atlantic multidecadal variability on anomalous temperature regimes formation in the Northern Eurasia

Abstract

The impact of Atlantic multidecadal variability (AMV) on anomalous regional temperature regimes formation in the Northern Eurasia during the year is investigated. We study the influence of AMO on the formation of the anomalous regional regimes of near-surface temperature for different seasons. To estimate AMV contribution, we analyzed numerical simulations with the atmospheric general circulation model (ECHAM5) coupled to the thermodynamic model of the upper mixed ocean layer using anomalous ocean heat convergence fluxes associated with the AMV. The results of the model experiment showed that AMV-related anomalous heat fluxes have a significant impact not only on changes in mean temperature, but also they can lead to an increase in the occurrence of regimes with anomalously low and high near-surface temperature deviations. It is found that anomalous heat fluxes may lead to an increase by more than two times of the probability of anomalously low temperatures in winter and spring with increasing mean temperature. An increase by 2-3 times of anomalously hot summer temperatures and anomalously low near-surface autumn temperatures in the Northern Eurasia is also observed.