Science Applications for GIFTS:: >Hyperspectral data from satellite-based sounders will
have an impact on a wide variety of atmospheric products.
GIFTS Interferogram Example:: A technologically advanced focal plane array provides a
128 x 128 field of view (fov) imaging capability. Each of the pixels yields an
interferogram, which can be transformed into spectra across the infrared measurement
range. The high spatial (4 km) resolution provides more cloud-free measurements.
GIFTS Spectrum Example:: The high spectral resolution provides information about
individual absorption lines. Current operational sounders measure across broad areas of
the spectrum, losing the detail needed to obtain important details about the vertical
profiles of atmospheric gasses.
GIFTS IR Measurements and Products::The GIFTS makes high spectral resolution
measurements across two regions of the Infrared portion of the electromagnetic spectrum.
This coverage includes transparent (window) regions of the atmosphere and regions
where constituent gasses are absorbing and emitting radiation. Temperature and moisture
profiles can be calculated by applying the high spectral resolution measurements in
absorption bands of CO2 and H2O. Created by combining multispectral observations,
derived products have many applications ranging from fire and aerosol detection to the
characterization of cloud properties to measurements of surface temperature over the land
and sea.
GIFTS Improvements over the GOES Sounding System::The high spectral resolution
yields many more individual observations than current broadband instruments. The
emission characteristics at high spectral resolution also yield information from a thinner
layer of the atmosphere, resulting in increased vertical resolution of the products.
Temp and Water Vapor Sounding::The great increase in the number of measurements
plus the increased vertical resolution result in significantly improved accuracy of the
vertical profiles of temperature and moisture, and their derived products, similar in
information content to a radiosonde. This improved accuracy will greatly improve short
term nowcasts and forecasts of sub-synoptic scale events. With these measurements
available every 15 minutes, the result is a true mesoscale observation system from space.
GIFTS Temperature Profile Example::GIFTS temperature and moisture profiles will have
detailed vertical resolution. Combined with the 4 km spatial resolution and the 15 minute
temporal resolution, GIFTS can monitor the evolving atmosphere in detail never before
captured, allowing for improved nowcasts and forecasts.
GIFTS Winds from Water Vapor Retrieval Tracking::Temperature and moisture profiles
from high spectral resolution measurements are interpolated to atmospheric levels. From
the time rate of change of water vapor mixing ratio at a given gridpoint, motion vectors
will yield accurate winds with accurate height assignments. Consequently, this approach
allows wind information at multiple levels and all gridpoints instead of having winds at
one or two levels and located only where tracers are found. More accurate winds greatly
increases our knowledge of the atmospheric dynamics.
GIFTS - Water Vapor Airborne Validation::The SSEC Scanning-HIS and the NASA
Langley NAST-I aircraft instruments have served as prototypes for GIFTS. These
prototypes demonstrated significant improvements in accuracy and facilitated the
development of high spectral resolution datasets.
Wind Measurement::This animation of NAST-I retrieved water vapor information depicts
the detail available from high spectral resolution measurements. The ER-2 aircraft flew a
racetrack flight pattern to cover the same region of the Earth and its atmosphere every 35
minutes. The animation was created from these scans. Southwesterly flow regimes are
present at 800 and 700mb will easterlies are present at 500 and 200mb. Significant
mesoscale detail is visible in the water vapor features.
Water Vapor Flux::A numerical model generated observation of water vapor as will be
observed within a 3 x 3 array of GIFTS “cubes” (i.e., field of regard). The animation
was generated for a region along the Louisiana/Texas Gulf coast for January 7, 2002.
The model generated temperature and moisture fields were converted to radiance
observations as would by the GIFTS at any instance of time. Moisture profiles were then
retrieved from the radiance fields. Shown is a ten minute interval animation of the
moisture “observed” by the GIFTS over a three hour period. The moisture flux can be
used to identify where storms will develop and the winds inferred from the moisture flux
can be used to obtain predictions of the storm motion.
Summary::GIFTS measurements will greatly improve weather nowcasting and
forecasting, as well as provide more detailed information for scientific studies. Its
applications will save lives with improved forecasts of severe weather, including severe
thunderstorms, hurricanes and mid latitude cyclones. Improved forecasts will greatly
benefit the economy by inspiring better agricultural planning and industrial practices.
GIFTS will also benefit climate research with improved detection of trace gases,
including greenhouse gasses, and aerosols.