Rain-Aerosol Relationships Influenced by Wind Speed

TitleRain-Aerosol Relationships Influenced by Wind Speed
Publication TypeJournal Article
Year of Publication2016
AuthorsYang, Yang, Russell Lynn M., Lou Sijia, Liu Ying, Singh Balwinder, and Ghan Steven J.
JournalGeophysical Research Letters
Abstract / Summary

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 CESM 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 mid-latitude 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 lead to increasing R by +0.99 mm day-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.

URLhttp://onlinelibrary.wiley.com/wol1/doi/10.1002/2016GL067770/abstract
DOI10.1002/2016GL067770
Journal: Geophysical Research Letters
Year of Publication: 2016

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 CESM 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 mid-latitude 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 lead to increasing R by +0.99 mm day-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.

DOI: 10.1002/2016GL067770
Citation:
Yang, Y, LM Russell, S Lou, Y Liu, B Singh, and SJ Ghan.  2016.  "Rain-Aerosol Relationships Influenced by Wind Speed."  Geophysical Research Letters.  https://doi.org/10.1002/2016GL067770.