Premium
The climatological relationship between tropical cyclones in the southwest pacific and the Madden–Julian Oscillation
Author(s) -
Diamond H. J.,
Renwick J. A.
Publication year - 2015
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.4012
Subject(s) - madden–julian oscillation , climatology , extratropical cyclone , tropical cyclone , cyclogenesis , tropical cyclogenesis , environmental science , oscillation (cell signaling) , atmospheric sciences , geology , cyclone (programming language) , geography , convection , meteorology , biology , field programmable gate array , computer science , computer hardware , genetics
The focus of this study is the climatological relationship between southwest Pacific Tropical Cyclone ( TC ) activity and the Madden–Julian Oscillation ( MJO ) on the interannual time‐scale. It investigates TC seasonal characteristics (e.g. cyclogenesis, track morphology, ex‐tropical transition, and intensity) as modulated by the phase and intensity of the MJO . The approach is novel as in addition to the focus on the intraseasonal variability of TCs there is also a focus on the interannual variability of TCs even though the MJO is an intraseasonal phenomenon. Links between the MJO , the Southern Annular Mode ( SAM ) and TC variability are also investigated. Using the MJO phases defined by Wheeler and Hendon (2004), southwest Pacific TC frequency exhibited a statistically significant decrease during MJO phases 2 and 3, and an increase during phases 6 and 7; and during the positive phase of the SAM , an increased frequency of TCs undergoing extratropical transition was observed. In summary, the results show a clear intraseasonal climatological relationship between specific phases of the MJO with respect to a decreased (increased) frequency of TCs during the paired MJO phases 2–3 (6–7); as well as the existence of a statistically significant relationship between the MJO and SAM with respect to the extratropical transition ( ETT ) of TCs . During positive phases of the SAM , coincident with weak interannual MJO phases 4–5 and 6–7, there are statistically significant greater frequency percentages of TCs undergoing ETT .