Winter Icing and Storms Project (WISP)

WISP is a multi-investigator program, including atmospheric scientists from NASA Langley Research Center, dedicated to the investigation of meteorological conditions that produce hazardous icing to aircraft. To a large extent, this entails forecasting and detecting regions of supercooled liquid water in the storms.

One of NASAs Earth Science Applications projects called ASAP or Advanced Satellite Aviation-weather Products is collaborating with WISP. NASA's Earth Science Enterprise recently identified aviation safety as one of 12 national applications to address that demonstrate science for society. The ASAP project is one way Langley supports this aviation safety effort. Langley's aeronautics heritage and excellence in atmospheric research provides the perfect environment for ASAP. Projects such as WISP provide ASAP an opportunity to validate its algorithms before they transition to operations.

ASAP is a collaborative effort with the FAA Aviation Weather Research Program (AWRP) to integrate satellite imagery and sounding data into aviation-related weather products resulting in increased forecast accuracy. The concept is being proven through the enhancement of current aviation-weather products by using existing Geostationary Operational Environmental Satellite (GOES) data and processing techniques to address known aviation hazards such as in-flight icing, atmospheric convection, and turbulence. This work will prepare the AWRP product development teams for the next generation of weather data from high-resolution, hyperspectral geostationary satellites. The results will, for example, enable pilots to identify developing weather systems several hours before clouds appear.

The FAA and NASA's Aviation Safety Program have identified weather as a factor in 30 percent of aviation accidents in the United States at a cost of three billion dollars annually. General aviation suffers the most from weather-related accidents and is a strong supporter of this program.

Aircraft are particularly vulnerable to supercooled water droplets because they convert to ice very quickly when they come in contact with other ice crystals in the cloud, or a cool surface such as that of an airplane wing. With the aid of the Ground-based Remote Icing Detection System (GRIDS), researchers can monitor clouds in the vicinity of airports and provide automated warnings of icing conditions aloft.

The GRIDS radar employs radar polarization techniques to recognize regions of acloud that are predominantly composed of water droplets and distinguish them from cloud regions that are predominantly ice crystals. These identifying radar polarization "signatures" rely on the information about particle shape that is contained in the depolarization ratio measured by the radar. Observed depolarization ratios are matched to the theoretical values expected from various cloud particle types to make the identification. Based on several years of research, signatures of numerous crystal types and droplets have been verified by in situ cloud sampling by aircraft.

The microwave radiometer permits the measurement of the total amount of liquid in the cloud as well as an estimate of the average temperature of the liquid. The radiometer provides independent confirmation of the presence of liquid (which is especially helpful when there is both liquid and ice present simultaneously in the atmosphere). GRIDS ingests temperature profiles from the Rapid Update Cycle (RUC) model from the National Oceanic and Atmospheric Administration's (NOAA) National Center for Environmental Prediction.

Contacts:

John Murray
NASA Langley Research Center
John.J.Murray@nasa.gov

Paul Stough
NASA Langley Research Center
H.P.Stough@nasa.gov

Science Goals:

• Provide detailed, near real-time forecasting and diagnosis of atmospheric conditions that could lead to hazardous icing of aircraft.
• Integrate satellite imagery and sounding data into aviation-related weather products resulting in increased forecast accuracy.
• Further develop and test the effectiveness of GRIDS, especially in the detection of supercooled water droplets.
• Learn how to deliver more accurate weather information to pilots with increased lead times.
• Gather data for the next generation of AWRP projects, including high-resolution, hyperspectral geostationary satellites.

Partners:

NASA Langley researchers will work in close collaboration with scientists from the NOAA Environmental Technology Laboratory, NOAA National Center for Environmental Prediction, the FAAs Aviation Weather Research Program (AWRP) and the National Center for Atmospheric Research (NCAR).

When:

February 15 - March 31 2004

Where:

Scientists will provide detailed, near real-time forecasting and diagnosis of atmospheric conditions as needed across northern and eastern Colorado, including the Denver area.

Links:

NASAs ASAP Program:

http://asd-www.larc.nasa.gov/new_AtSC/asap.html

For information about FAA Aviation Weather Research Program:

http://www2.faa.gov/aua/awr/

For more information about GRIDS:

http://www.etl.noaa.gov/technology/grids/

For information about NOAA Environmental Technology Laboratory:

http://www.etl.noaa.gov/

For information about NOAA National Center for Environmental Prediction:

http://wwwt.ncep.noaa.gov/

For information about NCAR:

http://www.ncar.ucar.edu/ncar/

For information about NASAs Aviation Safety Program:

http://www.aero-space.nasa.gov/goals/safety.htm

For information about NASAs Earth Science Enterprise:

http://www.earth.nasa.gov/