On Asian Dust Storm in China by Combining Daytime and Nighttime Terra and Aqua MODIS Data

A method to monitor one Asian dust storm occurred on April 28,2005 by means of four daytime and nighttime MODIS images that are boarded on Terra and Aqua platform is presented.Screening is important for dust storm detection.For daytime Terra and Aqua MODIS data,cloud screening is obtained by using visible and near infrared reflectance,single thermal infrared bright temperature threshold,and the difference of bright temperatures.In the evening TIR bands are only used to remove cloud effects.Then three thermal infrared(TIR),8.5 μm,11 μm,and 12 μm are used,and a tri-spectral technique presented by Ackerman(1997) to extract dust storm areas.It is found that combining brightness temperature differences BT8.5-BT11 with negative BT11-BT12 can detect dust storm.The dust storm areas can be separated from cloud and non-dust areas both on land and on the ocean.Furthermore,dust storm motion can be analyzed by these four scenes MODIS data within 24 h.The result is reasonable by validation with RGB composition method and meteorology data.The study also shows that MODIS data has great potential in dust storm research.