Intraseasonal Oscillation Intensity Variations of the Atmospheric Heat Source over the Tibetan Plateau and Their Relationship with Summer Precipitation

• DOI: 10.1175/jcli-d-24-0216.1
• Publication Date: 2025-01-08T13:17:26Z
• Authors: Zhu Zhu; Meirong Wang; Jun Wang; Anmin Duan; Boqi Liu; Zhongshui Yu
• Keywords: Intensity; Atmospheric Circulation; Oscillation (cell signaling); Low-pressure area; Madden–Julian oscillation

Abstract This study investigates intraseasonal oscillation intensity (ISOI) variations of the atmospheric heat source over Tibetan Plateau (TP) during 1979–2020 and their relationship with local summer precipitation. Our analysis reveals that 10–20-day predominates TP, followed by 20–30-day oscillation. ISOI both periodicities exhibit significant interannual decadal variations, notable weakening trends, particularly southern TP. Further indicates a strong between north-south reversed in precipitation across Mechanically, correlates decreased water vapor transport from Bay Bengal Arabian Sea into reduction, combined upper-lower circulation anomalies, leads to downdraft TP reduced here. Conversely, when weakens, diminishes while accumulating northeastern Together, an anti-clockwise meridional occurs northern causing increased Dynamic diagnostics further identifies negative temperature advection changes non-adiabatic heating (dQ/dt) are crucial for weakens. In contrast, involves horizontal relative vorticity middle upper levels, along dQ/dt lower which contributes Meanwhile, updraft is predominantly linked vorticity.