Variation in Dipole Blocking Associated with Arctic Warming in Winter: Potential Contributions to Cold and Extremely Cold Events over Eurasia

Chun Liu,Wei Song,Yuefeng Li

doi:10.3390/atmos10050249

Abstract

In this study, the barotropic mode of thermal forcing responsible for the difference in temperature between the Arctic and midlatitude regions was simplified by the nonlinear Schrӧdinger equation with disturbance terms using multiscale perturbation methods. The impact of Arctic warming on dipole blocking, which results in temperature anomalies over the midlatitudes of Eurasia, was studied using the direct perturbation theory for solitons. The results showed: (1) if only nonlinear effects exist between waves and zonal flows, a dipole blocking structure can present in the westerly air flows; (2) the temperature gradient between midlatitude warming and Arctic cooling inhibits the development of dipole blocking structures; and (3) Arctic warming is theoretically more conducive to intensifying the strength of dipole blocking and meridional activities over Eurasia and is more likely to cause the southward invasion of cold air from the Arctic, thereby inducing regionally cold and even extremely cold events in the mid- and low latitudes of Eurasia, including eastern China.

Highlights

Cold weather and climate events have occurred in many regions throughout the northern hemisphere over the past few decades, including the United States, China, and Europe.These events have been accompanied by strong storms, snowstorms, and record-breaking freezing rain and snow events
Two questions need to be addressed in relation to these extreme weather and climate events in midlatitudes: (1) Are these extremely cold midlatitude events during the northern hemisphere winter related to Arctic warming; (2) If a relationship does exist between these cold events and Arctic warming, what are the weather and climate processes and dynamic mechanisms that cause these extreme cold events in midlatitudes?
We simplified the barotropic modes of thermal forcing for the difference in temperature between the Arctic and midlatitude regions as a nonlinear Schrödinger equation with perturbation terms using the multiscale perturbation method

Summary

Introduction

Cold weather and climate events have occurred in many regions throughout the northern hemisphere over the past few decades, including the United States, China, and Europe. Yan et al [18,19] to analyze the effect of the thermal forcing term on solitary waves We combined these results with the topology of solitons to discuss the effect of Arctic warming on dipole blocking and its contribution to negative temperature anomalies over the mid-to-low-latitude regions of Eurasia in winter. Recent studies have found that Arctic warming can cause a stronger meridional circulation and a weaker westerly jet Under such circumstances, blocking can occur frequently in the northern hemisphere, including Europe and Asia, resulting in a higher frequency of cold air outbreaks. Eurasian temperatures, was studied via a direct approach to the perturbation theory

Schrödinger Equation in the Quasi-Geostrophic Model with Thermal Forcing

Dipole Blocking Structure without Thermal Forcing

Impact of Thermal Forcing on the Schrödinger Equation for Solitons

Impact of Arctic Warming on Dipole Blocking

Discussion and Conclusions