TAMDAR, the Rapid Update Cycle, and the Great Lakes Fleet Experiment

More than 60 TAMDAR sensors (see accompanying paper by Daniels et al.) have recently been deployed on turboprop aircraft operated by Mesaba Airlines (d. b. a. Northwest Airlink). This fleet of aircraft provides high vertical resolution sounding data at regional airports in the Midwestern United States, and generally provides high temporal resolution data at lower altitudes than is the case with currently available automated weather data from commercial jetliners. The sensors, developed jointly by NASA and AirDat LLC of Raleigh, NC, measure temperature, relative humidity, winds aloft, turbulence, and icing, and report these to the ground in real-time. The sensors will remain on the aircraft for at least 6 months.

NOAA’s Forecast Systems Laboratory (FSL) and National Weather Service will evaluate these data by performing several tasks.

• FSL will make TAMDAR data available to NWS weather forecaters on the FSL aircraft data web site and as AWIPS-displayable data files through its Meteorological Assimilation Data Ingest System (MADIS).
• NWS field forecasters will document and study those situations in which the TAMDAR data improves their understanding of weather situations and results in improved forecasts.
• To characterize wind, temperature, and humidity uncertainties, FSL will compare the TAMDAR data with those from other sensors such as radars, wind profilers, radiosondes, other aircraft, and automated surface stations.
• To begin to characterize turbulence and icing uncertainties, FSL will compare TAMDAR reports with relevant voice pilot reports.
• FSL will ingest the TAMDAR data into a retrospective test version of the RUC model and will study and document the effect these data have on model performance.

Because the Fleet Experiment started in late summer 2004, this will be a report on current, preliminary findings.