Three-Dimensional, Time-Dependent, Computer Simulations of the
Global Transport of the Kuwaiti Smoke by Wind, Its Removal
by Precipitation, and Its Effects on Climate



The Los Alamos general circulation model (GCM) was used to simulate the 
3D global distribution and evolution of the smoke from the burning oil
fields in Kuwait.  An assumed constant injection rate of 6.1 x 10^10
grams of soot per day having a visible absorption coefficient of 10
meters^2/gram and an infrared extinction coefficient of 1 meters^2/gram
(D. Engi & B. Zak 1991, Sandia National Laboratory).  Also assumed was
that this smoke is injected up to 3 km above the surface before the
model-predicted winds transports it and the model predicted precipitation
removes it.  This scenario ran several times on CRAY computers in the
Central Computing Facility, each
for 30 simulated days, some starting in January conditions, others in June.

It was found that, after 30 days, about 15% of the total soot that was
injected still remained in the atmosphere, in both seasons.  
The amount of soot in the
atmosphere at any given time depends on the local weather conditions
(simulated in the model).  Transient excursions of the smoke plume over
India and the central Soviet Union were observed in the simulations,
but the severe effects of the smoke were confined primarily to within
1000-2000 kilometers of Kuwait.  The attenuation of sunlight, averaged
over the last 20 days of the 30-day simulation, was 50% over Kuwait
and about 4% in the vicinity of India.  Although some heating of smoke
by sunlight does occur, more so in June then in January, very little smoke
is lofted into the stratosphere.  After about a week, the steady injection
of smoke is approximately balanced by the removal of smoke by rain, so
that about 3 x 10^11 grams of smoke remains in the atmosphere, mainly
over the Middle East.  Absorption of sunlight by the smoke causes the lower
atmosphere within about 1000 km of Kuwait to be heated by a few degrees
centigrade and the surface in this region to be cooled by several degrees.
The model results suggest that the smoke has little effect on the global 
climate.


Acknowledgement:  G.A. Glatzmaier, R.C. Malone, LANL