TY - JOUR
T1 - Synoptic characteristics, atmospheric controls, and long-term changes of heat waves over the Indochina Peninsula
AU - Luo, Ming
AU - Lau, Ngar Cheung
N1 - Funding Information:
Acknowledgements This study is partially supported by the National Natural Science Foundation of China (no. 41401052). The appointment of NCL at The Chinese University of Hong Kong is partially supported by the AXA Research Fund. The appointment of ML at The Chinese University of Hong Kong is supported by the Postdoctoral Fellowship Scheme of the Faculty of Social Science (no. 3132220) and the Focused Innovations Scheme (no. 1907001).
Publisher Copyright:
© 2017, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - The characteristics of heat wave (HW) events over the Indochina Peninsula are studied using the Climate Forecast System Reanalysis data for 1979–2010. HWs in the dry and wet seasons of Indochina are considered separately, and their typical synoptic behavior is examined in detail. Our results show that HWs in both seasons are accompanied by suppressed precipitation, and the region lies under an anomalously dry, hot, and subsiding atmospheric column. Further diagnoses reveal that HWs in the dry and wet seasons are linked to the weakening of the East Asian winter monsoon (EAWM) and the South Asian summer monsoon (SASM) circulations, respectively. On the one hand, HWs in the dry season are coincident with high-temperature anomalies over East Asia and accompanied by an anomalous cyclone over eastern China. The anomalous southwesterly flow over East Asia indicates a weakening of the climatological northeasterly circulation associated with the EAWM. On the other hand, HWs in the wet season are coincident with hot and dry anomalies in South Asia (i.e., Indian subcontinent). The anomalous easterly flow in that region opposes the climatological westerly regime of the SASM. Moreover, we found that the statistics for the frequency, duration, and amplitude of HWs for both seasons exhibit prominent intensifying trends, and the intensifying trends in the wet season are mostly about two to three times stronger than the dry season. These intensifying HWs activities are likely attributable to the weakening trend of monsoon circulations in recent decades.
AB - The characteristics of heat wave (HW) events over the Indochina Peninsula are studied using the Climate Forecast System Reanalysis data for 1979–2010. HWs in the dry and wet seasons of Indochina are considered separately, and their typical synoptic behavior is examined in detail. Our results show that HWs in both seasons are accompanied by suppressed precipitation, and the region lies under an anomalously dry, hot, and subsiding atmospheric column. Further diagnoses reveal that HWs in the dry and wet seasons are linked to the weakening of the East Asian winter monsoon (EAWM) and the South Asian summer monsoon (SASM) circulations, respectively. On the one hand, HWs in the dry season are coincident with high-temperature anomalies over East Asia and accompanied by an anomalous cyclone over eastern China. The anomalous southwesterly flow over East Asia indicates a weakening of the climatological northeasterly circulation associated with the EAWM. On the other hand, HWs in the wet season are coincident with hot and dry anomalies in South Asia (i.e., Indian subcontinent). The anomalous easterly flow in that region opposes the climatological westerly regime of the SASM. Moreover, we found that the statistics for the frequency, duration, and amplitude of HWs for both seasons exhibit prominent intensifying trends, and the intensifying trends in the wet season are mostly about two to three times stronger than the dry season. These intensifying HWs activities are likely attributable to the weakening trend of monsoon circulations in recent decades.
KW - Climate change
KW - East Asian winter monsoon
KW - Heat waves
KW - Indochina Peninsula
KW - South Asian summer monsoon
KW - Synoptic characteristics
UR - http://www.scopus.com/inward/record.url?scp=85037695601&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85037695601&partnerID=8YFLogxK
U2 - 10.1007/s00382-017-4038-6
DO - 10.1007/s00382-017-4038-6
M3 - Article
AN - SCOPUS:85037695601
SN - 0930-7575
VL - 51
SP - 2707
EP - 2723
JO - Climate Dynamics
JF - Climate Dynamics
IS - 7-8
ER -