TY - JOUR
T1 - Robust Enhancement of Tropical Convective Activity by the 2019 Antarctic Sudden Stratospheric Warming
AU - Noguchi, S.
AU - Kuroda, Y.
AU - Kodera, K.
AU - Watanabe, S.
N1 - Funding Information:
This work was supported by CREST, Japan Science and Technology Agency (JPMJCR1663) and Grants‐in‐Aid for Scientific Research (19K14798) from the Japan Society for the Promotion of Science. S. Noguchi would like to thank members of the Cloud‐Resolving Model Development and Application Group at JAMSTEC for helpful conversations. Special thanks are extended to P. Haynes and one anonymous reviewer for their thoughtful comments.
Publisher Copyright:
©2020. The Authors.
PY - 2020/8/16
Y1 - 2020/8/16
N2 - Tropical tropospheric responses to a sudden stratospheric warming (SSW) event that occurred over Antarctica in September 2019 have been investigated by conducting a series of ensemble forecast experiments. Comparative examinations between the normal forecast and the partially nudged forecast, whose stratospheric circulation is constrained to a reanalysis, reveal a significant enhancement/suppression in the convective activity (upwelling/downwelling) over the northern/southern part of the tropics. Such an acceleration of the Hadley circulation is set up by thermal structural changes in the upper troposphere and lower stratosphere. The tropical cooling caused by the enhanced Brewer-Dobson circulation destabilizes the environment there and stimulates deep cumulus convections. In this case, the southern area of the Asian monsoon region is particularly sensitive. Although details of the triggered response depend on the adopted cumulus parameterization scheme, a boosting tendency of the convective upwelling via the SSW is robust.
AB - Tropical tropospheric responses to a sudden stratospheric warming (SSW) event that occurred over Antarctica in September 2019 have been investigated by conducting a series of ensemble forecast experiments. Comparative examinations between the normal forecast and the partially nudged forecast, whose stratospheric circulation is constrained to a reanalysis, reveal a significant enhancement/suppression in the convective activity (upwelling/downwelling) over the northern/southern part of the tropics. Such an acceleration of the Hadley circulation is set up by thermal structural changes in the upper troposphere and lower stratosphere. The tropical cooling caused by the enhanced Brewer-Dobson circulation destabilizes the environment there and stimulates deep cumulus convections. In this case, the southern area of the Asian monsoon region is particularly sensitive. Although details of the triggered response depend on the adopted cumulus parameterization scheme, a boosting tendency of the convective upwelling via the SSW is robust.
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U2 - 10.1029/2020GL088743
DO - 10.1029/2020GL088743
M3 - Article
AN - SCOPUS:85089370697
VL - 47
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 15
M1 - e2020GL088743
ER -