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The following are some of
the USGCRP's major accomplishments related to the global water cycle during Fiscal Year 2001.
 Completed almost four years of rainfall measurements by the Tropical
Rainfall Measuring Mission (TRMM), which, combined with other satellite and
surface-based observations, has provided a greatly improved global tropical
rainfall climatology. TRMM also has provided the data for preparation of accurate
maps of the diurnal cycle of precipitation, contributing to a new benchmark
for documenting tropical precipitation. In parallel, TRMM data provide a more
accurate basis for verifying global precipitation weather forecasts, a goal
of the U.S. Weather Research Program.
Completed the first year of analysis of global measurements of
the radiative properties of clouds and aerosols taken by EOS Terra. These observations,
together with those of EOS Aqua (launch scheduled for late 2001/early 2002)
will reduce uncertainty in the determination of cloud/aerosol radiative forcing
and feedback processes involved in the heating and cooling of the Earth's surface
and atmosphere.
Developed improved representations for modeling of the land surface,
including topographic variability, soil physics, and snowpack physics. These
improvements will contribute to more accurate seasonal predictions of changes
in weather patterns associated with El Niño cycles, and resulting changes in
land surface hydrology.
Completed the second precisely controlled mapping of most of Antarctica
in a mode that will enable the calculation of surface flow rates. High-resolution
data from LANDSAT-7 and EOS Terra showed the early beginnings of a crack in
an Antarctic ice flow. The crack, found to be 25 km long and 400-500 meters
wide in January 2001, was growing at about 13 meters a day. This is the first
observation of the beginning of the formation of massive icebergs.
Provided the means for accurate, continuous measurements of water
vapor vertical profiles from field campaigns at one of the Atmospheric Radiation
Measurement (ARM) program sites. These new measurements provide an improved
understanding of the variability of atmospheric water vapor at all altitudes
of interest to climate and weather-prediction modelers.
Differentiated the chemical characteristics in spring snow melt
between cool morning periods and warmer periods later in the day. Increased
understanding of these processes will improve estimates of the impacts of global
change on water quality in streams and rivers carrying snowmelt water.
Analyses of data acquired with commercial aircraft have demonstrated
the ubiquity, globally and throughout the year, of air that circulates widely
in relatively thin layers in the troposphere (present in layers averaging about
1 km thick at altitudes from 2 to 12 km). The existence of these layers, which
can be characterized by their water vapor and ozone content, has important implications
for understanding the large-scale atmospheric circulation when the radiative
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Research Elements & Cross-cutting Activities
