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The Impact of Rain on Ocean Surface Waves and Currents
Author(s) -
Laxague Nathan J. M.,
Zappa Christopher J.
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 - 10.1029/2020gl087287
Subject(s) - current (fluid) , atmosphere (unit) , atmospheric sciences , momentum (technical analysis) , gravity wave , wind wave , geology , forcing (mathematics) , gravity current , ocean current , drag , precipitation , flux (metallurgy) , infragravity wave , environmental science , geophysics , climatology , wave propagation , meteorology , internal wave , mechanics , physics , oceanography , mechanical wave , longitudinal wave , materials science , finance , quantum mechanics , economics , metallurgy
Precipitation is an important component of the interaction between Earth's atmosphere and oceans, modifying air‐sea fluxes of momentum, heat, and gas. It has been hypothesized that rain's suppression of ocean surface gravity waves and centimeter‐scale wave enhancement should alter the nature of air‐sea momentum flux, resulting in increased near‐surface current. Here, we use field observations to describe this impact and measure the very near‐surface current response to rainfall. During heavy rain, surface‐roughening ring waves were generated and longer gravity waves were suppressed; immediately following, the magnitude of the near‐surface current increased in response to wind forcing but died as the rain subsided and long waves recovered. These first‐of‐their‐kind field observations indicate that rain reduces ocean wave form drag in favor of tangential stress, resulting in the acceleration of current near the sea surface.