The Glacier‐Climate Interaction Over the Tibetan Plateau and Its Surroundings During the Last Glacial Maximum.

Glacier growth affects the local climate, and in turn, can either promote or prohibit its own growth. Such feedback has not been considered in modeling the glaciers of the Tibetan Plateau and its surroundings (TPS) during the Last Glacial Maximum (LGM; ∼28–23 ka). We find that the volume/area of the glaciers simulated by a coupled glacier‐climate model is 20%/10% less than that by a standalone glacier model forced with fixed climate fields; glaciers advance toward their western rims and yet decrease in the interior of TPS. Such changes in spatial patterns improve model‐data comparison. Moreover, the expansion of glaciers warms the winter surface temperature of the eastern TPS and decreases precipitation almost everywhere. These effects are primarily due to the added surface elevation, which blocks the water vapor brought by westerlies and south‐westerlies, reducing precipitation and increasing surface temperatures to the east and northeast of the newly grown glaciers. Plain Language Summary: Depending on their area and volume, glaciers could impact regional atmospheric circulations, temperatures, precipitation, surface properties, etc. Changes in these climate variables would in turn feedback on the glacier growth and retreat. The glacial area over the Tibetan Plateau and its surroundings (TPS) should be much broader during the Last Glacial Maximum (LGM) than today, but glacier‐climate feedback was largely ignored in previous numerical studies. We show that the feedback significantly alters the simulated glacier area and distribution in LGM glaciers, and helps improve model‐data comparison. When glaciers grow, the surface elevation increases, which intercepts water vapor. Hence, more glaciers will grow along the western rim of TPS and less over the interior when the glacier‐climate feedback is considered. In the meantime, the winter surface temperature of the eastern Tibetan Plateau increases by more than 2 K and the precipitation over most of TPS decreases. Key Points: Coupled modeling of the Last Glacial Maximum glaciers and climate over the Tibetan Plateau and its surroundings is necessaryThe elevated glaciers blocked water vapor transport, reduced precipitation over most of TPS, and increased winter temperature in eastern TPSThe coupled glacial modeling decreases glacial area, and with changes in spatial distribution better matches the reconstructions [ABSTRACT FROM AUTHOR]