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On the relationship between the Madden‐Julian Oscillation and 2 m air temperature over central Asia in boreal winter
Author(s) -
Zhou Yang,
Lu Youyu,
Yang Ben,
Jiang Jing,
Huang Anning,
Zhao Yong,
La Mengke,
Yang Qing
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd025651
Subject(s) - madden–julian oscillation , climatology , anticyclone , troposphere , boreal , northern hemisphere , central asia , environmental science , advection , atmospheric sciences , surface air temperature , forcing (mathematics) , geology , precipitation , geography , convection , meteorology , physical geography , physics , paleontology , thermodynamics
Abstract Linear regression is used to explore the relationship between the Madden‐Julian oscillation (MJO) and 2 m air temperature (T2M) over central Asia in boreal winter during 1979–2012. During MJO phases 3 and 4 (7 and 8), T2M anomalies exhibit a significantly strong, negative (positive) response to the MJO from the Arabian Sea to northwestern China. The anomalies of T2M are essentially influenced by surface net downward long ( L down ) and shortwave radiations, which are caused by the changes in total cloud cover (TCC) and low‐level tropospheric air temperature. The anomalies of L down that are caused by TCC account for 20–65% of total L down . The remaining anomalies of total L down are explained by low‐level air temperature changes. The 850 hPa air temperature (T850) tendency is mainly affected by the vertical motion over central Asia during MJO phases 1, 2, 4–6, and 8, as well as over northern India during phases 3 and 7. Over Saudi Arabia, Afghanistan, Pakistan, Kazakhstan, and northwestern China, the anomalies of T850 tendency are mainly explained by the temperature advection during phases 3 and 7. TCC and vertical motion are affected by the evolution of the MJO event. The cyclonic (anticyclonic) circulation related to the MJO over central Asia during phases 3 and 4 (7 and 8) causes the transport of cold (warm) air over central Asia. The MJO can be a useful intraseasonal signal to predict winter T2M over central Asia, where temperatures would be colder (warmer) than normal during MJO phases 3 and 4 (7 and 8).