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Climate Variability Impacts on Global Extreme Wave Heights: Seasonal Assessment Using Satellite Data and ERA5 Reanalysis
Author(s) -
Patra Anindita,
Min SeungKi,
Seong MinGyu
Publication year - 2020
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2020jc016754
Subject(s) - teleconnection , climatology , antarctic oscillation , pacific decadal oscillation , significant wave height , storm , el niño southern oscillation , zonal and meridional , latitude , geology , environmental science , oceanography , wind wave , geodesy
This study examines the influences of major climate variability modes on global extreme significant wave height (SWH) during 1992–2016 using merged satellite altimeter records and ERA5 reanalysis data set. El Niño‐Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), North Pacific Oscillation (NPO), and Southern Annular mode (SAM) are considered during December–February (DJF), March–May (MAM), June–August (JJA), and September–November (SON). A nonstationary generalized extreme value analysis is applied to seasonal maxima of SWH (Hmax) to identify the regions with significant impacts of climate variability. In addition to major impacts over the northeastern North Pacific (NP) and Maritime Continent during DJF, signature of ENSO in Hmax is observed over the southeast South Pacific during all seasons associated with the Pacific South America pattern and over the western NP during JJA and SON through the El Niño‐East Asian teleconnection mechanism. Notable contribution of NAO to North Atlantic Hmax, resulting from north‐south movement of storm track, is observed during DJF and MAM. Increased Hmax is concentrated around the northeast NP during the positive phase of NPO during DJF, which accompanies Aleutian low strengthening and suggests possible combined influence with ENSO. SAM influences on Hmax are characterized by a zonal pattern in the Southern mid‐ and high latitudes around the year, with seasonally distinct zonal extent and meridional shifts. Overall, the satellite and reanalysis data exhibit consistent results. Hmax responses are generally in accord with extreme wind and sea‐level pressure gradient amplitude, supporting the wind‐driven extreme wave mechanisms.