A. L. Hoffman, C. E. Forest, and W. Li
Journal of Geophysical Research, D: Atmospheres (16 September 2014)
Exploring the impact of sea surface temperature (SST) anomaly patterns on local climate in major dust source regions helps clarify our understanding of variability in the global dust cycle. In contrast to previous work, this research focuses explicitly on the influence of SST anomalies on dust emissions and attempts to explain the mechanisms by which SST anomalies affect seasonal dust emissions. This study investigates the seasonal sensitivity of mineral aerosol emissions to SST anomaly patterns from the Bodele Depression, West Africa, Sahel, Kalahari Desert, Arabian Desert, and Lake Eyre basin. The global teleconnection operator, which relates regional climate responses to SST anomaly patterns, is estimated for relevant variables in an ensemble of the National Center for Atmospheric Research Community Atmosphere Model version 5 forced by randomly perturbed climatological SST fields. Variability in dust emissions from major dust sources is linked to tropical SST anomalies, particularly in the Indian and western Pacific Oceans. Teleconnections excited by remote SST anomalies typically impact dust emissions via changes in near-surface wind speeds and friction velocity. However, SST-driven impacts on the threshold friction velocity can be of the same order of magnitude as changes in the friction velocity, suggesting the impact of SST anomalies on precipitation and soil moisture is also significant. Identifying SST anomaly patterns as a component of internal variability in regional dust emissions helps characterize human influences on the dust cycle as well as improve predictions of climate, nutrient cycles, and human environments.
keywords: mineral aerosols; regional climate change; teleconnections; SST variability; dust; regional climate sensitivity; 0305 Aerosols and particles; 1637 Regional climate change; 1620 Climate dynamics; 3339 Ocean/atmosphere interactions; 3305 Climate change and variability