Premium
Global Scaling of Rainfall With Dewpoint Temperature Reveals Considerable Ocean‐Land Difference
Author(s) -
Ali Haider,
Peleg Nadav,
Fowler Hayley J.
Publication year - 2021
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 - 10.1029/2021gl093798
Subject(s) - environmental science , scaling , climatology , tropics , latitude , atmospheric sciences , global warming , climate change , geology , oceanography , geometry , mathematics , geodesy , fishery , biology
Short‐duration rainfall extremes are expected to intensify with warming at around 7%/K, following the Clausius‐Clapeyron (CC) relation, causing concomitant increases in flash floods. Observed hourly rainfall extremes show consistent CC‐scaling with dewpoint temperature across all land regions. Here, we use two global climate reanalysis products (ERA5 and MERRA‐2) to examine consistency in scaling with observations, in ungauged regions and over the oceans. We find that reanalyzes underestimate observed scaling, but ERA5 provides better estimates than MERRA‐2. Scaling rates at high latitudes and midlatitudes are similar to observations, at CC, while over the tropics mixed negative‐ and super‐CC scaling rates are seen. We show underestimation of scaling rates over the tropics is related to deficiencies in simulations of extreme rainfall over orographically complex and convection dominated regions. Importantly, both reanalyzes indicate scaling rates over the ocean are substantially higher than over land, with implications for extreme weather events originating over the ocean.