Rain-aerosol relationships influenced by wind speed

TitleRain-aerosol relationships influenced by wind speed
Publication TypeJournal Article
Year of Publication2016
AuthorsYang Y., Russell LM, Lou S.J, Liu Y., Singh B., Ghan SJ
JournalGeophysical Research Letters
Date Published2016/03
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000373109800059
Keywordsaerosol; AOD; Cloud microphysics; community atmosphere model; convective clouds; general-circulation model; invigoration; optical depth; parameterization; pollution; precipitation; rain; satellite; wind

Aerosol optical depth (AOD) has been shown to correlate with precipitation rate (R) in recent studies. The R-AOD relationships over oceans are examined in this study using 150-year simulations with the Community Earth System Model. Through partial correlation analysis, with the influence of 10m wind speed removed, R-AOD relationships exert a change from positive to negative over the midlatitude oceans, indicating that wind speed makes a large contribution to the relationships by changing the sea-salt emissions. A simulation with prescribed sea-salt emissions shows that wind speed leads to increasing R by +0.99mmd(-1) averaged globally, offsetting 64% of the wet scavenging-induced decrease between polluted and clean conditions, defined according to percentiles of AOD. These demonstrate that wind speed is one of the major drivers of R-AOD relationships. Relative humidity at 915hPa can also result in the positive relationships; however, its role is smaller than that of wind speed.

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