Air and Waste Management Association Professional Development Course AIR-257: Satellite Detection of Aerosols Instructor: Rudolf Husar, Ph.D. Professor of Mechanical Engineering Washington University, St. Louis, MO October 25, 2004, 9:00 a.m. - 12:00 p.m. Asheville, NC Aerosol - Free Quebec Smoke Reflectance Quebec Smoke AOT
In April 1998, several unusually intense dust storms were generated over the Gobi Desert by springtime cold weather systems with over 20 m/s surface wind speed.
The dust cloud from the April 19 storm was swiftly transported across the Pacific reaching North America within 5 days. Part of the cloud subsided to the surface between British Columbia and CA while another part was observed aloft in layers up to 10 km.
During the peak on April 29 the dust increased PM concentrations 20-50 g/m 3 over the West Coast and the daily PM10 concentration approached the health standard.
The largest dust storms of the season occurred on April 15 and 19.
TOMS data indicate that the April 19, 1998 storm was the most intense dust event in the 1997-99 period.
April 15 Dust Cloud Over Asia SeaWiFS data with TOMS overlays (green lines)
SeaWiFS satellite data indicate that the dust storms on April 15 and 19 originated from the same region of Gobi Desert.
The dust sources are streaks of dust plumes originating from specific patches of land.
April 19 Dust Cloud Over Asia SeaWiFS data with TOMS overlays (green lines) After about 500 km of transport, the plumes tend to merge and the streaky plume structure disappears. On April 19, the visibility was reduced due to dust throughout central and eastern Mongolia, and the optical thickness increased from < 0.5 on April 18 to > 2 on April 19. April 19, ‘98
Impact of Dust on Spectral Reflectance Excess spectral reflectance of dust over the ocean Change of the spectral reflectance of soil with increasing dust. Note, the yellow coloration of white clouds viewed through a dust layer.
Figure 3. Dust transport over the Pacific Ocean between April 21-25. In the SeaWiFS images [Kuring, 1998], the dust appears as a yellow dye marking its own position at noon each day.
Dust Cloud Over North America GOES 10 S GOES 10 Geostationary satellite image By April 27 th , the dust cloud rolled into North America and split with one branch heading southward along the CA coast and the another branch continuing eastward across the Canadian Rockies.
Regional average PM10 levels reached 65 µg/m 3 compared to typical values of 10-25 µg/m 3
On April 29, the PM10 exceeded 100 µg/m 3 over parts of Washington and Oregon
IMPROVE Fine Particle Dust Concentrations April 25, 1998 April 29, 1998 May 2, 1998 On April 25, the western U.S. was virtually dust-free, but reached high concentrations by April 29. On May 2, the elevated dust concentrations moved over the Rocky Mountains and the Colorado Plateau
Fine Particle Dust Ten Year Trends Figure 8. Ten-year trend of fine particle dust concentration at three IMPROVE monitoring sites.
Vertical Profile of Dust Cloud Over North America The height of the dust layer on April 27 was between 6-10 km Lidar backscatter at JPL, Pasadena. Lidar profiles at Salt Lake City
The Asian Dust Events of April 1998 Prepared by: R. B. Husar, D. Tratt, B. A. Schichtel, S. R. Falke, F. Li D. Jaffe, S. Gassó, T. Gill, N. S. Laulainen, F. Lu. M Reheis, Y. Chun, D. Westpha, B. N. Holben, C. Geymard, I. McKendry, N. Kuring, G. C. Feldman, C. McClain, R. J. Frouin, J. Merrill, D. DuBois, F. Vignola, T. Murayama, S. Nickovic, W. E. Wilson, K. Sassen, N. Sugimoto Paper to be submitted to the JGR issue on dust December 27, 1999 http://capita.wustl.edu/Asia-FarEast/reports/JGR/AsianDustEpisodeApril1998Draft5.htm
A Draft Summary Based on Reports and Data on the Web
Rudolf B. Husar and Bret Schichtel
CAPITA, Dec 1998
Location of fires (red dots) on May 15, 1998, based on Defense Meteorological Satellite Program ( DMSP ) satellite data NOAA’s Operational Significant Event Imagery (OSEI) Throughout the spring of 1998, thousands of fires in Central America have been burning with twice the intensity of normal springtime fires. Forest Fires over Central America
Smoke from the Central American Fires Based on SeaWiFS and other satellite imagery, thick smoke has been lingering over southern Mexico, Guatemala and Honduras and adjacent oceans throughout the spring season.
TOMS Aerosol Index GOES 8 Visible Imagery May 12 May 14 May 15 May 16 Smoke passes over Eastern North America
Daily TOMS images of absorbing aerosol index May 2 May 3 May 5 May 6 May 4 May 7 May 8 May 9 May 10 May 11 May 12 May 13 May 14 May 15 May 16 May 17 May 18 May 19 May 20 May 21 May 22 May 23 May 24 May 25 May 26 May 27 May 28 May 29 May 30 May 31
Average Excess TOMS Index for Mar., Apr., May 1998 Excess TOMS absorbing aerosol index averaged for March, April, May 1998 compared to 1999. The insert depicts the 1998 smoke impact from a global perspective.
Surface Ozone Concentration Superposition of daily maximum ozone and aerosol extinction maps derived from surface visibility.
PM10 concentration over the Eastern U.S. during the smoke event The smoke drifted into the US and Canada and caused exceedances of the PM standard, health alerts, and impairment of air traffic due to thick haze.
SeaWiFS Surface Reflectance on Clear and Smoky Days Spectral reflectance data derived from the SeaWiFS sensor on May 15, 1998; b) Excess aerosol backscattering over water.
Goes 8 Visible Image HY-SPLIT Trajectories HY-SPLIT Plumes TOMS Aerosol Index Comparison of HYSPLIT Predictions of airmass transport to GOES 8 and TOMS imagery
TOMS : The Big Picture Absorbing Aerosol Index
July 5: The near-source, low level smoke is not detected by TOMS
July 5 July 6 July 7 July 8 July 9 July 6-7: Smoke plume signal is very intense over S. Ontario and NE US. July 8-9: Transport to the Atlantic. Where will the smoke reach Europe? How intense, will it be detectable? Would anyone run Hysplit, ATAD? July 10 July 11