From the Atlantic to Asia: How an ocean thousands of miles away dictates rainfall on the Tibetan Plateau

Deep in the heart of Central Asia, the Kunlun Mountains form a vital barrier on the northern Tibetan Plateau. Their rainfall is a lifeline, feeding the oases and rivers of the arid Tarim Basin. While scientists have mapped the region’s basic climate patterns, one question remained: what drives the large year-to-year swings in summer rainfall here?

The answer, according to a new study in Climate Dynamics, originates from an unexpected source: the North Atlantic Ocean.

The research reveals that the anomalous dipole pattern of sea surface temperature in the North Atlantic affects the summer precipitation on the northern slope of the Tibetan Plateau through atmospheric teleconnection processes.

“On the northern slope of the Tibetan Plateau, annual rainfall is dominated by summer precipitation, with interannual variability accounting for most of the changes,” said first author Shijie Tang, a PhD student at the Institute of Atmospheric Physics, Chinese Academy of Sciences. “We found that horizontal water vapor convergence—particularly associated with anomalous southerly winds—plays the leading role in regulating summer rainfall variability on the northern slope of the Tibetan Plateau.”

Further analysis reveals that the North Atlantic sea surface temperature dipole influences tropospheric circulation through anomalous heat fluxes, triggering Rossby waves that propagate eastward along the “Western Europe–northern Central Asia” pathway. These waves induce anticyclonic circulation and anomalous southerly winds over the Kunlun Mountains and surrounding areas, thereby enhancing water vapor transport and ultimately altering summer rainfall patterns.

Corresponding author Tianjun Zhou noted that the research provides a new framework for understanding rainfall variability by connecting remote ocean-atmosphere interactions to local water processes, significantly improving the potential for climate risk management in the region.