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Distinguishing Variability Regimes of Hawaiian Summer Rainfall: Quasi‐Biennial and Interdecadal Oscillations
Author(s) -
Luo Xiao,
Wang Bin,
Frazier Abby G.,
Giambelluca Thomas W.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl091260
Subject(s) - climatology , anticyclone , rossby wave , precipitation , pacific decadal oscillation , environmental science , sea surface temperature , madden–julian oscillation , tropical cyclone , typhoon , teleconnection , cyclogenesis , el niño southern oscillation , atmospheric sciences , cyclone (programming language) , geology , geography , meteorology , convection , field programmable gate array , computer science , computer hardware
Abstract Summer precipitation in Hawai'i accounts for 40% of the annual total and provides important water sources. However, our knowledge about its variability remains limited. Here we show that statewide Hawai'i summer rainfall (HSR) variability exhibits two distinct regimes: quasi‐biennial (QB, ~2 years) and interdecadal (~30–40 years). The QB variation is linked to alternating occurrences of the Western North Pacific (WNP) cyclone and anticyclone in successive years, which is modulated by the intrinsic El Niño–Southern Oscillation biennial variability and involves a positive feedback between atmospheric Rossby waves and underlying sea surface temperature (SST) anomalies. The interdecadal variation of HSR is largely modulated by the Pacific Decadal Oscillation through affecting upstream low‐level humidity that affects topographic rainfall. HSR shows weak long‐term drying trend during 1920–2019. This first description of the major physical drivers of summer rainfall variability provides key information for seasonal rainfall prediction in Hawai'i.