Snow–precipitation coupling and related atmospheric feedbacks over North America

• Published in: Atmospheric Science Letters
• Main Authors: Diro, Gulilat Tefera, Sushama, Laxmi
• Other Authors: Natural Sciences and Engineering Research Council of Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Canada; North Atlantic; North Atlantic oscillation
• Online Access: http://dx.doi.org/10.1002/asl.831; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fasl.831; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/asl.831

Understanding snow–precipitation coupling mechanisms is of great importance both from theoretical and operational considerations. Here, carefully designed climate model experiments, with and without interactive snow, are conducted to study snow–precipitation coupling mechanisms over North America. Coupling hotspots are identified over southern Canada during December and over the central United States during January. The hotspot over southern Canada involves a positive snow–atmosphere feedback mechanism, whereby snow modifies the large‐scale atmospheric features, which resembles the positive phase of North Atlantic Oscillation. This favors storm activity and enhanced snow over the region. The coupling over the central United States during January, on the other hand, is tied to the albedo effect of snow, which leads to cooling of the lower atmosphere, which in turn determines the precipitation phase, favoring snow formation over rain. The results from this study, in general, are informative for sub‐seasonal to seasonal prediction of winter precipitation for the studied regions.