Influence of Asian Mountains on Arctic Pressure System and the Stratospheric Ozone

The majority of Asian mountain region is made up of the Tibetan Plateau (TP), often referred to as the “Third Pole”. The TP, characterized by its high elevation, is a critical and sensitive region for climate change, experiencing a warming trend at a rate twice that of the global average. Its significance extends beyond local climate impacts, exerting a profound influence in shaping global climate dynamics. While its influence on the Asian is well-documented, its impact on the remote Arctic region has remained unclear. By conducting orographically sensitive experiments using the Whole Atmosphere Community Climate Model Version 6, we shed light on the intricate relationship between the TP and Arctic climate variability. The results reveal that the Asian topography significantly influences Arctic pressure anomalies by modulating the Aleutian Low–Icelandic Low seesaw teleconnection. Furthermore, the topography facilitates the stratosphere-troposphere coupling, leading to the change of the stratospheric polar vortex in its strength and position. In addition to the impact on atmospheric circulation, the response of the Arctic ozone levels to the removal of the Asian mountain is also investigated. It is demonstrated that the topography significantly enhances the Arctic stratospheric ozone during winter, with a notable increase of 15% in the lower Arctic stratosphere. This increase is attributed to the intensified residual mean circulation transport, which is primarily influenced by the robust strengthening of planetary waves induced by Asian topography. The enhancement of planetary waves results in a weakened polar vortex, further promoting ozone accumulation in the Arctic region, ultimately influencing the dynamics and chemistry of the Arctic stratosphere. Overall, this research underlines the significant role of the Asian topography in driving Arctic climate variability and stratospheric ozone dynamics, providing valuable insights into the mechanisms underlying paleoclimatic evolution and atmospheric circulation.