Observations from the Global AMDAR Program

1. Observations From the Global AMDAR Program Presentation to WMO TECO-20054-7 May 2005by Jeff SticklandTechnical Coordinator, WMO AMDAR Panel

2. AMDAR = Aircraft Meteorological Data Relay AMDAR is: • A fully automated upper air observing system; • Uses existing aircraft and airline infrastructure including: • standard installed high quality sensors for wind, temperature and turbulence plus height (pressure), time and position; System Description • Collects high quality upper air observations of wind speed and direction, temperature, and sometimes turbulence and humidity; • From many existing commercial aircraft; • In collaboration with national domestic and international airlines; • onboard avionics and communications hardware and software; • Airlines normally use the international communications system called AircraftCommunications and Reporting System (ACARS). Global servicesare provided by 2 companies – ARINC and SITA.

3. FITTED WITH EXISTING SENSORS + AVIONICS HARDWARE + AVIONICS SOFTWARE + COMMUNICATIONS AMDAR SOFTWARE = + System Description (cont.) • airline ground-based data processing systems; • No new hardware is required on the aircraft; • The only additional requirement to make AMDAR work is special AMDAR software installed in the aircraft avionics or communications hardware; • Humidity sensors are being developed and will be added in the future to SOME aircraft; TYPICAL AMDAR INSTALLATION

5. Why is AMDAR Data Needed? • To provide a cost effective source of upper air observations to support national, regional and global basic meteorological operations and research; • AMDAR data can be used in most meteorological applications that use upper air data obtained from conventional observing systems. Vertical profiles of temperature and wind are often the most valuable: • Examples in operational bench forecasting for the short to medium term include- Severe weather forecast and warning services; Public weather forecast and warning services; Aviation weather services (enroute and terminal area forecasts supporting airlines, air traffic control and airport operations; Marine and industrial applications; Environmental monitoring and warning applications; Climate studies, etc.

6. To meet the NWP community’s requirement for greater quantities and improved coverage of relevant upper air data; • For forecast verification; • To help provide a more comprehensive assessment of the atmosphere for local modelling research, local forecasting, etc; • To provide data from data sparse areas around the world to improve local forecasts and to contribute to the WMO World Weather Watch Global Observing System • OperationalCost compared to radiosonde is 1%

7. BASIC Data Data Requirements Desirable Horizontal Spatial and Temporal Density: 1 profile on 250 km grid at 3 hourly intervals

8. Data Requirements (cont.) Additional Data

9. Mandatory and Optional Reported Elements Element Mandatory/Optional Requires Additional Onboard Processing Aircraft identifier M Phase of flight M Latitude M Longitude M Day & time of observation M Pressure altitude M Static air temperature M Wind direction M Wind speed M Maximum wind M Roll & pitch angle flag M * Humidity O * Turbulence O * Icing O *

11. 24 Hour Global Coverage 13 April 2005 Courtesy NOAA FSL

12. 24 Hour AMDAR Profiles 13 April 2005 Courtesy NOAA FSL

13. E-AMDAR Temperature Quality Frequency distribution of the mean temperature difference (OBS–Background) KNMI QEV Report - April - June 2001

14. E-AMDAR Wind Speed Quality Frequency distribution of the mean wind speed difference (OBS–Background) KNMI QEV Report - April - June 2001

15. WVSSII on N407 Versus Sonde at Mexico City, 12:53, 28 March 2005

16. LIT WVSS-2 vs. Raob Comparison

17. SDF WVSS-2 Comparisons 31 MAR 05 Comparisons of 4 WVSS-2 aircraft on descent into SDF. Between 06z and 08z the profiles changed markedly as a line of thunderstorms approached and moved through, along with cold front passage. 2 Ascents are also included. Things stabilized by around 10z.