|Title||Interannual to decadal climate variability of sea salt aerosols in the coupled climate model CESM1.0|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Xu L, Pierce DW, Russell LM, Miller AJ, Somerville RCJ, Twohy CH, Ghan SJ, Singh B, Yoon J-H, Rasch PJ|
|Journal||Journal of Geophysical Research-Atmospheres|
This study examines multiyear climate variability associated with sea salt aerosols and their contribution to the variability of shortwave cloud forcing (SWCF) using a 150 year simulation for preindustrial conditions of the Community Earth System Model version 1.0. The results suggest that changes in sea salt and related cloud and radiative properties on interannual timescales are dominated by the El Nino-Southern Oscillation cycle. Sea salt variability on longer (interdecadal) timescales is associated with low-frequency variability in the Pacific Ocean similar to the Interdecadal Pacific Oscillation but does not show a statistically significant spectral peak. A multivariate regression suggests that sea salt aerosol variability may contribute to SWCF variability in the tropical Pacific, explaining up to 20-30% of the variance in that region. Elsewhere, there is only a small sea salt aerosol influence on SWCF through modifying cloud droplet number and liquid water path that contributes to the change of cloud effective radius and cloud optical depth (and hence cloud albedo), producing a multiyear aerosol-cloud-wind interaction.
"The results show that at interannual timescales, global patterns of sea salt, and related cloud and radiative properties are primarily responding to the ENSO cycle, with the largest spatial patterns of coherent variability found primarily in the tropical Pacific. This is true even though the greatest sea salt atmospheric burdens are found in the Southern Ocean. The relationship between ENSO and the total burden of sea salt aerosols arises primarily through the modulation of surface emissions of sea salt via ENSO's effects on wind speed."