Interdecadal reversal in the relationship between Arctic sea ice and the Tibetan Plateau temperature over the past century

Abstract

Changes in Arctic sea ice have been shown to affect the climatic variability of the Tibetan Plateau (TP), but it remains unclear whether this Arctic-TP link has been stable over the past century. Using multiple reanalysis datasets (1900–2021), we found an interdecadal reversal in the relationship between winter Barents-Kara Sea ice concentration (BKSIC) and TP surface air temperature (TPSAT). In response to BKSIC loss, an out-of-phase pattern of “warm Arctic-cold TP” occurred during 1950–1975 (P1), while an in-phase pattern of “warm Arctic-warm TP” occurred during 1985–2021 (P2). The reversal of the BKSIC-TPSAT link is associated with changes in the position and strength of the subpolar and subtropical jet streams and quasi-stationary Rossby waves. During P1, the TPSAT was influenced by two distinct zonally oriented wave trains, associated with sea ice loss over the Greenland-Barents Kara Seas, the negative phase of the Atlantic Multidecadal Oscillation (AMO), and the positive phase of the Arctic Oscillation (AO). The north branch of the wave train propagates eastward along the intensified subpolar jet stream, while the south branch of the wave train originated from the North Atlantic and propagates eastward through the subtropical jet stream into the southern TP. In contrast, during P2, prominent BKSIC loss with positive AMO leads to a weakened subpolar jet stream, which favors the meridional propagation of the wave train into the southern TP. This study highlights the potential role of BKSIC in driving differing TP atmospheric thermal conditions in the context of distinct AMO phases.