Climate variability

Study analyzes how the Arctic drives Eurasian climate variability

In recent years, a cooling trend in Eurasia and a warming trend in the Arctic have been observed by various sources. The presence of a cause and effect relationship in this scheme has been much debated for a long time.

Schematic view of multisphere interactions. Image Credit: Yongkun, Xie

A study published in the journal Climatic dynamics, by scientists from the Institute of Atmospheric Physics of the Chinese Academy of Sciences and Lanzhou University, provides some clues on the matter. Their results indicate that the Arctic climate is considered to be one of the factors driving the entire decadal trend and variability in Eurasian temperature.

Scientists have found a view of dynamic and thermodynamic coupling in how the Arctic drives Eurasian climate variability and basic multi-sphere interactions. In addition, a comparison was made between the cases on several time scales, ie the global trend, the inter-annual and decadal variability.

In summer, key factors in multi-sphere interactions are sea ice, superficial solar radiation, and absorption of heat below the surface of the oceans. In winter, key factors are sea ice, area sensible heat, diabatic heating of the atmosphere, interaction between arctic and mid-latitudes, and large-scale distribution.

Dr. Yongkun Xie, Study Lead Author, Collaborative Innovation Center for Western Ecological Security, Lanzhou University

The story starts from summer when the absorption of solar radiation by the underground ocean above the sea ice loss region (Barents-Kara Sea) is enhanced. Then the energy is rejected to the air by sensible heat in winter via vertical diffusion, resulting in local circulation anomaly and increased warming.

The powerful background baroclinicity of the air at mid-high latitudes further stimulates the interactions that occur between the atmospheric circulation and the sensible heat of the sea surface, and ultimately produces the anticyclonic circulation over the Arctic-Eurasian sector and warm arctic-cold Eurasia (downstream of Arctic warming enhancement).

The Complete Mechanics of Summer Earthsurface and subsurface ocean with winter atmosphere suggests Arctic driving role.

Yimin Liu, corresponding author of the study and professor, Institute of Atmospheric Physics, Chinese Academy of Sciences

Several previous studies have reached conclusions by generalizing interannual variability to global trends, and have therefore given rise to much debate. The study could explain this dispute by indicating that the situation of the interannual variability is very complicated compared to the decadal variability and the overall trend. This is due to the persistence of the impact of summer sea ice on winter climate variation, which is small compared to interannual variability.

This work was financially supported by the National Natural Science Foundation of China.

Journal reference:

Xie, Y. et al. (2021) A dynamic and thermodynamic coupling view of the links between Eurasian cooling and Arctic warming. Climatic dynamics.