Open AccessInfluence of stratospheric sudden warming on the tropical intraseasonal convection
Author(s) -
Feiyang Wang,
Yuanyuan Han,
Shiyan Zhang,
Ruhua Zhang
Publication year - 2020
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/ab98b5
Subject(s) - extratropical cyclone , madden–julian oscillation , climatology , stratosphere , northern hemisphere , convection , environmental science , atmospheric sciences , troposphere , sudden stratospheric warming , geology , meteorology , geography , polar vortex
Madden–Julian oscillation (MJO), the dominant mode of intraseasonal variability in the tropical troposphere, has recently been shown to have a great impact on Northern Hemisphere (NH) extratropical stratosphere. But the influence of the variability in the extratropical stratosphere on MJO is seldom reported. In this study, the influence of major, mid–winter NH stratospheric sudden warmings (SSWs) on the MJO is investigated using meteorological reanalysis datasets. Our analysis reveals that SSWs also exert considerable influence on tropical intraseasonal convection. The occurrences of MJO phases 6 and 7 significantly increase during around 20 d after the onset of SSWs, corresponding to enhanced convective activity over the equatorial Central and Western Pacific. Then in the following days, the coherent eastward propagation of tropical intraseasonal convection resembles the periodic variation in a typical MJO. These results suggest that the extratropical stratosphere affects the organized tropical intraseasonal convection, and variability of the tropical intraseasonal convection related to MJO can be better grasped by taking extratropical stratospheric variability into account. Considering the complex interaction between MJO and extratropical stratosphere, further work on comprehensive understanding of the relationship between SSWs and MJO is required in future studies.