Last Updated:
February 28, 2007
GCRIO Program Overview
Library
Our extensive collection of documents.
Privacy Policy |
 Archives of the
Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 12, NUMBER 5, MAY 1999OZONE DEPLETION
Item #d99may19
 “A Model-Derived Global Climatology of UV Irradiation at the
Earth’s Surface, A. A. Sabziparvar, K. P. Shine, and P. M. de F.
Forster, Photochemistry and Photobiology, 69 (2), 193-202
(1999).
A multistream radiative transfer model was used to calculate the
geographic distribution of the UV-A and UV-B dose rates at the surface of
the Earth. It used a multiyear climatology that included the effects of
ozone, clouds, surface pressure, surface albedo, temperature, and
aerosols. The results indicated that the most important factor in
determining the dose is the Sun’s position. Clouds reduce the dose
from a few percent under clear-sky conditions to 45% where midlatitude
depressions occur frequently.
Item #d99may20
“Present and Future Trends in the Atmospheric Burden of
Ozone-Depleting Halogens,” S. A. Montzka et al., Nature, 398,
690-694 (1999).
An analysis of atmospheric concentrations of ozone-depleting halogen
species showed a decline since 1994 across a large number of chemicals led
by the decline of trichloroethane, a cleaning solvent. Its decline has now
peaked. Any future declines in emissions of ozone-depleting compounds will
have to come from limitations on emissions of other chemicals, notably
Halon-1211 (CBrClF2), whose atmospheric concentration has remained
constant and is retarding the overall decline of ozone-depleting halogens.
Guide to Publishers
Index of Abbreviations
|
Library 