Atmospheric Freezing Level Height Changes

ABSTRACT Previous studies have found that the freezing level height (FLH) increases under the background of global warming, with negative effects on the global cryosphere, especially over mountain regions. In this study, with observation and model simulations, global FLH changes are updated to 2023. It is found that there are relatively smaller positive FLH trends and changes over the Tropics, but higher FLH changes over the extra‐Tropics with maximum FLH rises over high latitudes in the northern hemisphere. The temporal FLH variations are largely driven by the variability of tropical sea surface temperature. Comparison with glacier mass balance records indicates that these observed FLH changes over Arctic and high mountain stations have led to significant glacier mass losses, with accelerated losses in recent decades. Based on model simulations, tropical middle to high troposphere temperature shows maximum increases over the last several decades of the 21st century.