A Dipole Pattern of Summer Precipitation over Mid-high Latitude Asia and Related Snow Cover Anomalies in the Preceding Spring

• Published in: Atmospheric and oceanic science letters = Daqi-he-haiyang-kexue-kuaibao Vol. 7; no. 4; pp. 364 - 368
• Main Authors: Jin-Ping, Han, Ge, Liu, Yu-Fei, Xin
• Format: Journal Article
• Language: English
• Published: Beijing Routledge 01.01.2014; KeAi Publishing Communications Ltd; Chinese Academy of Meteorological Sciences, Beijing 100081, China
• Subjects: Animal migration; Anomalies; Anticyclones; Atmospheric precipitations; climatic anomaly; Cyclones; dipole; Planetary waves; Precipitation; Rain; Rainfall; Snow; Snow cover; Spring; Summer; Wave energy; Asia; precipitation; snow cover; climatic anomaly; dipole
• ISSN: 1674-2834; 2376-6123
• DOI: 10.3878/j.issn.1674-2834.14.0012

A dipole pattern of summer precipitation over the mid-high latitudes of Asia, which is characterized by opposing summer precipitation variations between the Mongolian and Northeast China (MNC) region and the West Siberian Plain (WSP), is found to be clear and stable on both interdecadal and interannual scales during 1981-2011. Spring snow cover anomalies over a small region within the WSP and the Heilongjiang River (HR) region are closely related to the variation of this dipole mode during the subsequent summer, and they can therefore be considered as forecasting factors. Our statistical results imply a potential process explaining the relationship between the spring snow anomalies and the summer rainfall dipole. Corresponding to the snow anomalies, Rossby waves propagate along a path from the WSP region, via the Mongolian Plateau, to the Stanovoy Range during summer. At the same time, Rossby-wave energy divergences and convergences along this path maintain and reinforce an anomalous cyclone and anticyclone pairing over the Asian continent, which is significantly linked to opposite summer precipitation anomalies between the MNC and WSP regions. Numerical experiments are needed to further confirm the above conjecture and demonstrate the detailed physical mechanisms linking the spring snow cover anomalies and summer precipitation dipole.