A new satellite-based global climatology of dust aerosol optical depth

December 5, 2019

CW3E graduate student Kara Voss, with her advisor and co-author Amato Evan, recently published a paper in the Journal of Applied Meteorology and Climatology entitled, “A new satellite-based global climatology of dust aerosol optical depth” (Voss & Evan 2019). This paper describes and validates a new set of daily satellite observation-derived estimates of dust between 2001 and 2018. These new estimates compare well with ground-based estimates of dust over the southwestern U.S. and the Barbados. The daily estimates were then used to assess broad characteristics of the global dust cycle, including seasonality (Fig 1, below). This paper also investigates regional trends in dust between 2001 and 2018. It was found that dust has decreased over Asia and increased significantly over the Sahara, Middle East, and parts of Eastern Europe. Previous literature has indicated a link between trans-Pacific dust and precipitation over California during atmospheric rivers (ARs). Dust has the potential to enhance precipitation, as it is able to form ice in clouds at much warmer temperatures than ice would form without dust. However, limited observations of dust over the Pacific have made investigation of this process difficult. This set of estimates provides a new tool for investigating the relationship between dust and ARs.

Figure 1: Figure 10 from Voss and Evan (2019): a-d) Seasonal mean dust aerosol optical depth from the MODIS Terra averaged over the period from 2001 to 2018 and e-h) seasonal mean dust aerosol optical depth from AVHRR over the period from 1981 to 2018. The long-term global mean 1-sigma uncertainty over the ocean for each season and dataset is featured in the bottom left-hand corner of each panel.

Voss, K.K., and A. Evan, 2019: A new satellite-based global climatology of dust aerosol optical depth. J. Appl. Meteor. Climatol., 0, https://doi.org/10.1175/JAMC-D-19-0194.1.