Issue 10 Volume 41 May 16, 2003

developing nations and large-scale biomass fires add to the global pollution burden. Ozone and aerosols are two components
of pollution that contribute to radiative forcing of the earth s climate. In turn, as climate changes, rates of chemical and
microphysical reactions may be perturbed. Considering the earth as a coupled chemical-microphysical-climate system poses
challenges for models and observations alike. These issues were the topic of a Workshop held in May 2002 at NASA GSFC
s Laboratory for Atmospheres. Highlights of the Workshop are summarized in this article.
Author
Global Air Pollution; Atmospheric Chemistry; Climatology; Meteorology
20030032334 Instituto Nacional de Pesquisas Espacias, Sao Jose dos Campos, Brazil
Rainfall Climate Variability Dynamics Over South America
Parraga, Guillermo Oswaldo Obregon; 2003; 198 pp.; In Portuguese; Original contains color illustrations
Report No.(s): INPE-8604-TDI/789; Copyright; Avail: CASI; A09, Hardcopy
Intraseasonal time-scales of climate variability over Brazil, and interannual and larger time-scales climate variability over
South America were studied using daily (1979-1990) and monthly (1951-1990) mean rainfall data and several statistical
methods. The results show that the seasonal and interannual rainfall variability over South America have intrinsic regional
features with prominent and persistent annual cycle. The semiannual cycle is predominant over northern Amazon (high
persistence) and Southern Brazil (low persistence). The seasonal mean rainfall distribution is strongly related to the statistics
of probabilities in all seasons. With respect to intraseasonal variability over Brazil, it was found that there are two dominant
oscillations with periods of 20 and 40 days with distinct characteristics. The 20 day oscillation shows greater dependence on
baroclinic waves, while the 40 day seems to be more related to the global scale oscillations and apparently interacts with
greater intensity with the tropical atmosphere. Regarding the interannual variability, it is observed that precipitation over South
America is modulated by El Nino/South Oscillation (ENSO). However, this modulation is present in the distinct periods, 3.7
and 5 years. The 5 years oscillation is predominant over equatorial regions, while the 3.7 years oscillation is predominant over
Southern Brazil. Both are modulated by Tropical Atlantic, but with different intensities. The linear trends and climate change
over South America show coherent space temporal distributions. Negative trends of the annual precipitation over the
maximum rainfall area, related to the climatological region of the South Atlantic Convergence Zone (SACZ), and positive
trends over Southern Brazil were observed. These patterns are results of the intense negative tendency occurred in summer
over the maximum rainfall area and during spring season over Southern Brazil. The trends seem to be associated with the
observed climate change in the mid 70’s, which is related to the sea surface temperature change, mainly in the Pacific Ocean.
This abrupt climate change affected almost the whole South America, except Northeast Brazil, where precipitation shows high
interannual variability and apparent quasi-decadal variability.
Author
Climate Change; Brazil; South America; Rain; Periodic Variations
20030032344 NASA Goddard Space Flight Center, Greenbelt, MD, USA
SHADOZ (Southern Hemisphere Additional Ozonesondes): A Tropical Ozonesonde-Radiosonde Network for the
Atmospheric Community
Thompson, Anne M.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Schmidlin, Francis J.; [2003]; 27 pp.; In English; Original
contains color illustrations
Report No.(s): Paper 1455; Copyright; Avail: CASI; A03, Hardcopy
A lack of sounding data has limited the accuracy of ozone satellite retrievals in the tropics and our understanding of
chemical-dynamical interactions in a region strongly influenced by natural variability and anthropogenic activity. In 1998,
NASA s Goddard Space Flight Center, NOAA’s Climate Monitoring and Diagnostics Laboratory (CMDL) and a team of
international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap
in tropical ozone soundings. SHADOZ augments launches at selected sites and provides a public archive of ozonesonde and
radiosonde data from twelve tropical and subtropical stations at http://croc.gsfc.nasa.gov/shadoz. Instrumentation, data and a
summary of the first scientific findings from SHADOZ are presented.
Author
Radiosondes; Ozone; Southern Hemisphere; Tropical Regions
20030032366 NASA Goddard Space Flight Center, Greenbelt, MD, USA
Preliminary Analysis and Simulations of July 23rd Extended Anvil Case
Lin, R.-F.; Demoz, B.; McGill, M.; Heymsfield, G.; Sassen, K.; Bui, P.; Heymsfield, A.; Halverson, J.; Rickenbach, T.; Poellot,
M.; Lare, A.; [2003]; 1 pp.; In English; CRYSTAL Science Team, 24-28 Feb. 2003, Salt Lake City, UT, USA; No Copyright;
Avail: Other Sources; Abstract Only
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