Rain‐aerosol relationships influenced by wind speed

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 10 m 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 +0.99 mm d −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 915 hPa can also result in the positive relationships; however, its role is smaller than that of wind speed.