TY - JOUR
T1 - Summer heat extremes in northern continents linked to developing ENSO events
AU - Luo, Ming
AU - Lau, Ngar Cheung
N1 - Funding Information:
Original content from this work may be used under the terms of the . Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Guangdong Pearl River Talents Program 2017GC010634 National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809 41401052 41871029 yes � 2020 The Author(s). Published by IOP Publishing Ltd Creative Commons Attribution 4.0 license
Publisher Copyright:
© 2020 The Author(s). Published by IOP Publishing Ltd.
PY - 2020/7
Y1 - 2020/7
N2 - Understanding the variations of extreme weather/climate events is important to improve the seasonal forecast skill of such harmful events. Previous studies have linked boreal summer hot extremes to decaying El Nĩo-Southern Oscillation (ENSO) events at the interannual scale, but how these hot extreme episodes respond to developing ENSO events remains unclear. Using observational analyses, we demonstrate strong linkages between developing ENSO and extreme heat events in northern continents. In particular, heat extremes in North America, Eastern Europe-Central Asia and Northeast Asia tend to be more frequent during La Nĩa developing summers and less frequent during El Nĩo developing phases. Associated atmospheric changes reveal that developing ENSO events feature a circumglobal teleconnection (CGT) pattern over the mid-latitudes. In the La Nĩa developing summer, this CGT pattern exhibits enhanced geopotential height and anomalous anticyclones over North Pacific, North America, Eastern Europe-Central Asia and Northeastern Asia, and the jet stream generally shifts northward. The atmospheric circulation changes lead to more persistent weather conditions that favor extreme heat events in mid-latitudes. Conversely, opposite changes associated with developing El Nĩo can inhibit heat extremes in the above locations. The responses of heat extremes to different types (i.e., conventional Eastern Pacific and Modoki Central Pacific) and durations (1 and 2 year) of ENSO events are also discussed.
AB - Understanding the variations of extreme weather/climate events is important to improve the seasonal forecast skill of such harmful events. Previous studies have linked boreal summer hot extremes to decaying El Nĩo-Southern Oscillation (ENSO) events at the interannual scale, but how these hot extreme episodes respond to developing ENSO events remains unclear. Using observational analyses, we demonstrate strong linkages between developing ENSO and extreme heat events in northern continents. In particular, heat extremes in North America, Eastern Europe-Central Asia and Northeast Asia tend to be more frequent during La Nĩa developing summers and less frequent during El Nĩo developing phases. Associated atmospheric changes reveal that developing ENSO events feature a circumglobal teleconnection (CGT) pattern over the mid-latitudes. In the La Nĩa developing summer, this CGT pattern exhibits enhanced geopotential height and anomalous anticyclones over North Pacific, North America, Eastern Europe-Central Asia and Northeastern Asia, and the jet stream generally shifts northward. The atmospheric circulation changes lead to more persistent weather conditions that favor extreme heat events in mid-latitudes. Conversely, opposite changes associated with developing El Nĩo can inhibit heat extremes in the above locations. The responses of heat extremes to different types (i.e., conventional Eastern Pacific and Modoki Central Pacific) and durations (1 and 2 year) of ENSO events are also discussed.
KW - El Niño-Southern Oscillation
KW - circumglobal teleconnection
KW - interannual variability
KW - jet stream
KW - summer heat extremes
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U2 - 10.1088/1748-9326/ab7d07
DO - 10.1088/1748-9326/ab7d07
M3 - Article
AN - SCOPUS:85082525930
SN - 1748-9318
VL - 15
JO - Environmental Research Letters
JF - Environmental Research Letters
IS - 7
M1 - 074042
ER -