2008-04-10 Intercontential Dust Transport Guest Lecture - Presentation Transcript
Global Distribution and Transport of Air Pollution Presented at The Haagen-Smit Symposium: From Los Angeles to Global Air Pollution Lake Arrowhead, April 9-12, 2001 Rudolf Husar CAPITA, Washington University , St. Louis
Background
Global-scale air pollution existed since…..
The difference is that now we can observe it!
Outline of Presentation
Major pollutant sources and emissions
Observation-based global chemical climatology of major gases and aerosols
Illustration of global-scale dust and smoke events
Opportunities and challenges of the the 21 st century
Industrial Sulfur Emission Density
The regional hot-spots for industrial sulfur emissions are in
E. North America,
Europe and
E. Asia
Long Term Trends
North America : roughly constant for the past century
Europe: Rise after WW II but leveled off since 1990
East Asia: Sharp rise since the 1960s.
Regional hot-spots for industrial sulfur emissions Eastern North America, Europe East Asia
Continental Surface Visibility (Human Observers)
NOAA NCDC Global Summary of the Day (SOD) 7000 Observations
Low Visibility High Visibility
Extinction coefficient (visibility) for SE Asia
The most intense and persistent regional haze is over India
During 1997 biomass fires in Indonesia caused unusually intense haze Sep, Oct, Nov Dec, Jan, Feb
The haze over N. America is modest compared to hazy regions of Africa, E. Asia and S. America
Extinction coefficient (visibility) for N. America Jun, Jul, Aug Dec, Jan, Feb
Haze over China SeaWiFS
Industrial haze covers most of Eastern China
Haze is confined to low-lying areas and valleys
The Asian Dust Event of April 1998 On April 19, 1998 a major dust storm occurred over the Gobi Desert The dust cloud was seen through SeaWiFS, TOMS, GMS, AVHRR satellites The dust transport was followed on-line by an an ad-hoc international group China Mongolia Korea
SeaWiFS/TOMS data for April 21 shows dust transport to the Pacific Japan
Trans-Pacific Dust Transport The dust cloud traversed the Pacific in 6 days at about 4 km altitude As the dust approached N. America, it subsided to the ground
Asian Dust Cloud over N. America On April 27, the dust cloud rolled into North America. The regional average PM10 increased to 65 g/m 3 In Washington State, PM10 exceeded 100 g/m 3 Reg. Avg. PM10 100 g/m 3 Hourly PM10
Fine Particle Dust Concentrations (IMPROVE) April 25, 1998 April 29, 1998 May 2, 1998 On April 25, the western U.S. was virtually dust-free. Highest concentration was an April 29. On May 2, the high levels moved (?) to the Colorado Plateau.
Summary of Global Air Pollution and Transport
The global sulfur emissions have shifted from N. America and Europe to East Asia.
The industrial ‘belt’, 30-60 deg N, is dominated by anthropogenic SO x , NO x and O 3 . This conforms to the conventional wisdom since the 1970s.
Recent satellite data show that NO x , HC and aerosols are dominated by biomass burning in the subtropics and the southern hemisphere. ??
The radiatively active global aerosol is dominated by smoke and dust, rather then by industrial sulfates as we have presumed.
Episodic trans-continental transport of dust and smoke (ozone?) can now be detected and modeled routinely.
Such extra-jurisdictional ‘pollution’ events cause significant episodic impact on the air quality of N. America.
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