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Floods in the Southern Alps of New Zealand: the importance of atmospheric rivers
Author(s) -
Kingston Daniel. G.,
Lavers David A.,
Hannah David M.
Publication year - 2016
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.10982
Subject(s) - hydrometeorology , orographic lift , extratropical cyclone , precipitation , climatology , atmospheric circulation , geopotential height , geopotential , orography , flash flood , flooding (psychology) , environmental science , overbank , geology , hydrology (agriculture) , flood myth , meteorology , geography , fluvial , psychology , paleontology , archaeology , structural basin , psychotherapist , geotechnical engineering
Extremely high precipitation occurs in the Southern Alps of New Zealand, associated with both orographic enhancement and synoptic‐scale weather processes. In this study, we test the hypothesis that atmospheric rivers (ARs) are a key driver of floods in the Southern Alps of New Zealand. Vertically integrated water vapour and horizontal water vapour transport, and atmospheric circulation, are investigated concurrently with major floods on the Waitaki River (a major South Island river). Analysis of the largest eight winter maximum floods between 1979 and 2012 indicates that all are associated with ARs. Geopotential height fields reveal that these ARs are located in slow eastward moving extratropical cyclones, with high pressure to the northeast of New Zealand. The confirmation of ARs as a contributor to Waitaki flooding indicates the need for their further exploration to better understand South Island hydrometeorological extremes. Copyright © 2016 John Wiley & Sons, Ltd.