Springtime Aerosols over Eastern Asia
Springtime Aerosols over Eastern Asia
31 March 2007
31 March 2007, marked opening ceremonies for the first GreenChina Day, established to increase awareness of the need for environmentalprotection. As reported by ShanghaiDaily.com, however, the ceremony in Beijingsaw an unwelcome guest: Gobi Desert dust.Roughly 2,000 kilometers south of the capital city, air quality also suffered,in this case from fires in Southeast Asia.
The Ozone Monitoring Instrument (OMI) flying onboard the Aura satellite measures the thickness of light-absorbing aerosolstinysolid or liquid particles suspended in the atmosphere. OMI captured these imageson March 30 (top) and March 31 (bottom). The images superimpose a color-codedscale of aerosol thickness onto a natural-color image of eastern Asia, the Seaof Japan, and the western Pacific Ocean. These images track the eastwardmovement of aerosols into the Beijing region, and show aerosols blowing eastwardout of Southeast Asia, dissipating as they travel. Red areas indicate whereaerosols are thickest or where aerosols float over reflective clouds, which tendto make the aerosol concentration appear more intense than it actually is.
Aerosols south of 30 degrees latitude likely result from smoke from biomassburning. To the north, aerosols probably result from dust. In both cases, thetime of year plays a role. Southeast Asian farmers often prepare for the growingseason by setting agricultural fires each spring. Accidental fires also springup readily at this time of year. Meanwhile, Gobi Desert dust storms generallypeak in the spring then gradually decline throughout the summer. The March 31dust storm that blanketed Beijing marked the first such storm of 2007.
(source: EarthObservatory)
