Weather forecasters in the middle of the United States are making better local predictions for pilots and others thanks to an airborne sensor being tested by NASA's Aviation Safety Program.
A team, led by researchers at NASA's Langley Research Center in Hampton, Va., designed, built and equipped dozens of Mesaba Airlines aircraft with the Tropospheric Airborne Meteorological Data Report (TAMDAR) instrument. Mesaba is a Northwest Airlink affiliate headquartered in Minneapolis, Minn., that flies primarily shorter commuter routes.
The sensor allows aircraft to automatically sense and report atmospheric conditions. Observations are sent by satellite to a data center on the ground that processes and distributes up-to-date weather information to forecasters, pilots and those who brief pilots.
"Initial research shows TAMDAR makes a 10 to 20 percent improvement in forecast error in numerical models," said Taumi Daniels, TAMDAR project leader. "And that's just with temperature." The sensor also measures humidity, pressure, winds, icing and turbulence with the help of location, time and altitude provided by built-in Global Positioning System technology.
The instrument, which is very compact and weighs only one-and-a-half pounds, has been flying on 63 Mesaba planes for more than a year as part of a Great Lakes Fleet Experiment. The team tested the sensor in an operational environment for the first time to help determine the value of airborne observations on aviation forecasts.
Large airliners fly above most weather and collect limited atmospheric data. When equipped with the sensor, regional aircraft, which typically fly below 25,000 feet often in the weather, can provide more information to forecasters and the aviation community.
The information the team collects can also benefit all weather forecasts and weather forecasting models because it increases the number of observations in the lower atmosphere. Currently there are only 70 weather balloon sites in the continental United States that are used to collect temperature, wind and moisture data from twice-daily atmospheric soundings. The Great Lakes Fleet Experiment added 800 more daily atmospheric soundings.
"Meteorologists here at the National Weather Service have found TAMDAR to be useful in forecasting severe thunderstorms, dense fog, precipitation types of winter storms and low-level wind shear," said Richard Mamrosh, National Weather Service meteorologist in Green Bay, Wis. "In summertime its best use is in determining if and when thunderstorms might develop. In wintertime it really helps in determining whether a storm will bring sleet, freezing rain or snow."
Private industry, meteorologists, researchers and scientists at weather forecast offices are part of the partnership that analyzes the data. The partners include NASA; AirDat L.L.C, Morrisville, N.C.; the Federal Aviation Administration; the National Oceanic and Atmospheric Administration; the National Center for Atmospheric Research, Boulder, Colo.; Massachusetts Institute of Technology Lincoln Laboratory, Lexington, Mass.; Meteorological Service of Canada, Montreal; UK MET Office, London; and Meteorological Network of Europe, Toulouse, France.
The NASA Aviation Safety Program is part of NASA's Aeronautics Research Mission Directorate. The focus of the program is on the way vehicles are designed, built, operated, and maintained. Scientists and engineers in this program are developing principles, guidelines, concepts, tools, methods, and technologies to address four areas: aircraft aging and durability, integrated intelligent flight deck technologies, integrated vehicle health management, and integrated resilient aircraft control.
For more information on NASA's Aeronautics Research Mission Directorate please check the Internet at:
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