Study on the Formation of Cold Air Damming and Its Synoptic Impacts

Cold air damming (CAD) is a mesoscale weather phenomenon caused by low-level cold air blocked by terrain. In the Northern Hemisphere, CAD usually occurs on the eastern side of mountains, resulting in increased cloud cover, decrease in temperature, and changes in precipitation types and distribution. CAD develops throughout the year, and often causes freezing rain in cold season, and severe convective weather such as thunderstorm, wind and hail in warm seasons. The reshaping of geostrophic adjustment under the terrain effect is the dynamic basics of CAD formation, but the thermal factors such as cold advection, adiabatic and non-adiabatic cooling are also crucial to the formation and development of CAD. Although mesoscale numerical models have significantly improved the predictability of CAD events, these models still tend to underestimate their impacts and duration. Even the rapidly updated high-resolution mesoscale models still undervalue the effects of solar shading. Therefore, CAD prediction has always been a difficult worldwide problem for researchers and forecasters. This paper mainly reviews the CAD research history from spatial-temporal distribution, synoptic impacts, formation mechanism and prediction. There is an absence of research on the most significant CAD on the eastern Tibetan Plateau.