In the heart of Central Asia, the Kunlun Mountains form a crucial natural barrier on the northern Qinghai-Tibet Plateau. Their rainfall feeds the oases and rivers of the arid Tarim Basin, making it a lifeline for the region. While scientists have long documented the area's basic climate patterns, one key question has remained: What drives the large year-to-year fluctuations in summer rainfall?

A team led by researchers from the Institute of Atmospheric Physics of the Chinese Academy of Sciences has found an answer — the North Atlantic Ocean. Their findings were recently published in the journal Climate Dynamics.

The study reveals that an abnormal dipole pattern in North Atlantic sea surface temperatures influences summer precipitation on the northern slope of the Qinghai-Tibet Plateau through atmospheric teleconnection processes.

Summer rainfall accounts for most of the annual precipitation in the region, and its variability is largely shaped by horizontal water vapor convergence — particularly driven by anomalous southerly winds.

The researchers explain that the North Atlantic sea surface temperature dipole affects tropospheric circulation through abnormal heat fluxes, generating Rossby waves that travel eastward along the "Western Europe–northern Central Asia" pathway. These waves create anticyclonic circulation and unusual southerly winds over the Kunlun Mountains and surrounding areas, enhancing water vapor transport and ultimately altering rainfall patterns.

This discovery establishes a new framework for understanding rainfall variability by linking remote ocean–atmosphere interactions to local hydrological processes. The findings could improve climate risk management in the region, the researchers noted.