Assessment of Temperature and Humidity Changes Associated With the September 2009 Dust Storm in Australia

Thomas A. Jones, Sundar A. Christopher
2011 IEEE Geoscience and Remote Sensing Letters  
A historic dust storm affected the eastern portions of 5 Australia between 22 and 24 September 2009, causing significant 6 reductions in air quality and visibility. Using multiple satellite 7 remote sensing data sets and meteorological information, we assess 8 the distribution of dust aerosols and their potential effects on the 9 Earth-atmosphere system. Spaceborne active lidar data showed 10 that dust aerosols were located up to 2 km above the surface. 11 The thickness of the dust plume
more » ... e dust plume (0.55-µm aerosol optical thick-12 ness > 1.0) reduced surface visibility to below 2 km. Dew-point 13 depressions of 20 • C or more occurred after passage of the dust 14 plume, with decreases in surface temperature observed at some 15 locations. Between the surface and 2-km level, temperature data 16 show a cooling of ∼ 10 • C in the hours after passage of the 17 cold front along which dust aerosols had converged. However, 18 much of the temperature change that occurred is a result of cold 19 air advection behind the northward traveling plume. Radiative 20 transfer modeling suggests that only up to 1 • C per day of this Q1 21 cooling is due to the decrease in solar radiation reaching the 22 surface layer. Radiative transfer modeling also indicates a net 23 warming of up to 2 • C per day within and above the dust layer, 24 possibly offsetting some cooling aloft due to the cold front passage. 25 Modeling results indicate that expected aerosol radiative effects 26 to temperature are small compared to synoptic influences and are 27 unlikely to be sampled in observations under this scenario since 28 the magnitudes of these effects are quite small. 29
doi:10.1109/lgrs.2010.2063693 fatcat:kn57hxv3tneuxkafydiwoeqrgu