Dominant controls of cold-season precipitation variability over the high mountains of Asia

A robust understanding of the sub-seasonal cold season (November-March) precipitation variability over the High Mountains of Asia (HMA) is lacking. Here, we identify dynamic and thermodynamic pathways through which natural modes of climate variability establish their teleconnections over the HMA. First, we identify evaporative sources that contribute to the cold season precipitation over the HMA and surrounding areas. The predominant moisture contribution comes from the mid-latitude regions, including the Mediterranean/Caspian Seas and Mediterranean land. Second, we establish that several tropical and extratropical forcings display a sub-seasonally fluctuating influence on precipitation distribution over the region during the cold season. Many of them varyingly interact, so their impacts cannot be explained independently or at seasonal timescales. Lastly, a single set of evaporative sources is not identifiable as the key determinant in propagating a remote teleconnection because the sources of moisture anomalies depend on the pattern of sub-seasonally varying dynamical forcing in the atmosphere.

Automated summary

This study explores the variability of cold season precipitation in the High Mountains of Asia (HMA) and identifies the factors that influence it. The results indicate that the mid-latitude regions are the main sources of moisture, and various tropical and extratropical forcings have sub-seasonal impacts on precipitation distribution in the region. The sources of moisture anomalies depend on the pattern of sub-seasonally varying dynamical forcing in the atmosphere.