A study of the impact of dust on tropical storms using satellite measurements

Dust plays an important role in aerosol direct radiative forcing (IPCC 2007). As an important source of ice nuclei, dust may also play important role in aerosol indirect forcing (Demott et al., 2010). Recent CALIPSO observations suggest that dust can catalyze the freezing of supercooled cloud droplets, trigger precipitation processes and thus affect cloud life cycle (Hu et al., 2010; Creamean, 2013). Spatial and temporal statistics of CALIPSO observations indicate strong anti-correlation of the occurence of dusts and supercooled liquid water clouds (Hu et al., 2010).

Combined CALIPSO/CloudSat measurements suggest that dust can also alter the duration and intensity of convective rainfall within tropical storm (Min et al., 2009). Dust can also change cloud water path and thus change cloud albedo (Huang et al., 2006). Dust absorbs solar radiation and thus changes global radiative cooling of the atmosphere (Huang et al., 2009), while global radiative cooling of the atmosphere plays an important role in water cycle (Stephens and Hu, 2010).

Long range transport of dust has been documented in many publications. Lidar measurements from space provide unique 3D dust aerosol information to help aerosol transport models improve their simulations of dust transport processes (Liu et al., 2008; Uno et al., 2009; Creamean et al., 2013). In this study, we use 8 years of collocated satellite measurements (CALIPSO, CloudSat, AMSR-E, CERES and MODIS) to study the impact of dust on the tropical systems. CALIPSO lidar data will provide accurate classification of dusts, water clouds and ice clouds. Collocated CALIPSO, CloudSat and AMSR-E data will be used for studying the relation among dust presence, cloud thermodynamic phase and precipitation. Collocated CALIPSO, MODIS and CERES observation will be used for studying impact of dust on the radiative energy budget.