Winter Weather Research
Research activities related to winter weather are designed to improve the nowcast and forecast of winter weather conditions that impact aviation operations (e.g., deicing of aircraft, runway clearing, sanding, and plowing, and air traffic operations) at airports. These activities have focused on development of a machine to produce snow in a reliable and repeatable fashion in order to test deicing fluids; development of a hotplate snowgauge; evaluation of snowgauges; operation of a ground-based winter test facility at the Marshall field site; and support for operational Weather Support for Deicing Decision Makers (WSDDM) systems at several U.S. airports. Current sources of funding are the FAA Aviation Weather Research Program (AWRP), FAA Technical Center, NSF, and the City of Denver.
FY06 Accomplishments:
The most important accomplishment was the development of an All-Weather Check Time system. "Check Time" is a UCAR-patented technology for ground deicing that provides users with an aircraft independent wall clock time that indicates when an applied aircraft deicing fluid is close to failure based on the current minute by minute snowfall rate and temperature. This work builds on an earlier Snow Check Time system which was tested at Denver International Airport and shown to provide value to users. The new All-Weather Check Time system adds three additional sensors which allow the system to provide Check Times for all precipitation types, including ice pellets, snow pellets, freezing rain and drizzle. Other accomplishments by the winter weather team include the successful demonstration of an improved snowband forecasting system that uses a nudging approach to assimilate NEXRAD radar data into a forecast. A successful demonstration of the snow machine's ability to perform deicing fluid testing at a temperature close to 0 ºC, a difficult temperature range at which to conduct testing, was also performed.
FY07 Plans:
The All-Weather Check Time system will be demonstrated at Pittsburgh International Airport in conjunction with Integrated Deicing System (IDS), the company which deices USAIRWAYS aircraft. As part of this test, real-time holdover times will be provided via radio transmission to the USAIRWAYS Check Airman to obtain feedback on the operational impact of this system. Pittsburgh was chosen for this demonstration in order to obtain data on ice pellets as well as freezing rain. Ice pellets have been recognized by the deicing industry as an important weather type that has had significant operational impacts on aviation but has not, to date, been reported with sufficient accuracy. As a result, holdover times for ice pellets have not yet been established. The inclusion of a GEONOR snowgauge in the All-Weather Check Time system will allow determination of the mass accumulation rate of ice pellets in real-time. Observers at the site will verify the presence of ice pellets and other precipitation types. Results will be reported at the May SAE Ground Deicing meeting in San Diego.