Observations From the Global AMDAR Programme Presentation to WMO TECO December 2006 by Michael Berechree Technical Coordinator, WMO AMDAR Panel

System Description Aircraft Meteorological DAta RelayAMDAR = AMDAR is: A fully automated upper air observing system; High quality upper air observations of wind speed and direction, temperature, and sometimes turbulence and humidity; Available from many existing commercial, private and military aircraft;

System Description = FITTED WITH EXISTING SENSORS + AVIONICS HARDWARE + AVIONICS SOFTWARE + COMMUNICATIONS AMDAR SOFTWARE + AMDAR uses existing aircraft and airline infrastructure: Wind, temperature and turbulence plus height (pressure), time and position; Onboard avionics and communications hardware and software; and Aircraft Communications And Reporting System (ACARS). Global services are provided by ARINC and SITA.

System Description

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

Additional Data Data Requirements

Mandatory and Optional Reported Elements ElementMandatory/OptionalRequires Additional (M/O)Onboard Processing Aircraft identifierM Phase of flightM LatitudeM LongitudeM Day & time of observationM Pressure altitudeM Static air temperatureM Wind directionM Wind speedM Maximum windM Roll & pitch angle flagMYES HumidityOYES TurbulenceOYES IcingOYES

AMDAR data have similar accuracy to that of radiosonde data and can be used in the same manner. A typical AMDAR vertical sounding of temperature and wind produces a profile that is typically less than 1% of the cost of a radiosonde profile. 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; and For forecast verification; To meet the NWP community’s requirement for greater quantities and improved coverage of relevant upper air data; Why is AMDAR Data Needed?

AMDAR is particularly useful for now-casting situations where conditions are changing rapidly and are therefore of special use to the aviation industry. Such applications include:  Surface and upper air forecasts of wind and temperature;  Thunderstorm genesis, location and severity;  Wind-shear location and intensity e.g. dangerous low-level jets;  Low cloud and fog formation, location and duration;  Turbulence location and intensity; and

Why is AMDAR Data Needed? AMDAR data significantly improved NWP wind forecasts. For example, 3-hour wind forecast error was reduced by 40% with an overall improvement of 11%; 12-hour wind forecasts of winds improved by 5%; Impacts of these improved wind forecasts are better en-route and terminal management of aircraft and therefore leads to subsequent financial savings gained by the airlines; and

The benefits of AMDAR data are global and large for forecasts out to 48 hour. Why is AMDAR Data Needed?

The benefits of AMDAR data are global and large for forecasts out to 48 hour. Why is AMDAR Data Needed?

Over 200,000 high quality observations per day being exchanged on the GTS Over 2,800 reporting aircraft world wide Growth in AMDAR data

Courtesy NOAA ESRL/GSD 24 Hour AMDAR Coverage 30 November 2006

Courtesy NOAA ESRL/GSD 24 Hour AMDAR Profiles 30 November 2006

Distribution map of the average number of aircraft reports decoded per 24- hour periods in 10 deg. lat-lon boxes. Courtesy Environment Canada. Data Availability

Courtesy NOAA ESRL/GSD AMDAR Temperature and Wind Profiles

High quality AMDAR data is suitable for use in all operational meteorological applications. Quality of observations received from each reporting aircraft is routinely monitored by regional and global centres. The NCEP is the WMO designated lead centre for monitoring aircraft observations. Data quality of data from most large jet transports is high while the quality of similar data derived from many smaller regional and commuter aircraft is often not suitable for meteorological use. Data quality from CRJ passenger aircraft (bias based on Numerical Model output) - Courtesy: Meteorological Service of Canada Monthly mean temperature bias of all European aircraft that reported in September Data Quality

Frequency distribution of the mean temperature difference (OBS–Background) KNMI QEV Report – January – March 2004

Data Quality Frequency distribution of the mean wind speed difference (OBS–Background) KNMI QEV Report – January – March 2004

AMDAR Humidity Measurement Air Sampler 24 cm SEB Cylindrical Sampling Tube Sensor System SEB (System Electronics Box) Air Sampler Hoses (Heated and Non-Heated) for Interconnection Air Sampler - SEB SpectraSensors, WVSS-II Near-Infrared Absorption Spectrometer Based on Tunable Diode LaserHeated Inlet HoseOutput: Water Vapor Mass Mixing Ratio

SEB FWD Hose, Heated Hose, Non- Heated Skin Air Sampler Frame Air Sampler AMDAR Humidity Measurement

AMDAR data as per ARINC 620v4 Supplement 5 SEBSEB Probe Hoses 28 VDC ARINC bus 429 ATC AMDAR AOC Air Traffic Service Unit VHF HF SATCOM Flight Management System Aircraft Interface Host Platform Hardware ATC Weather AOC WVSS-II Step 1 Step 2 Airbus Solution for AMDAR

AMDAR Humidity Measurement Recent comparison of WVSS-2 Water Vapour Profile and Radiosonde profile, November 2006 Courtesy NOAA ESRL/GSD

AMDAR Humidity Measurement Relative Humidity differences between WVSS-II and Radiosondes for 2-week test period Tests have shown that WVSS-II water vapour data: - are comparable to radiosonde moisture data; - can be easily obtained in otherwise data sparse areas; - profiles are observed at airports where aviation forecasters need them the most; and - costs are substantially less than traditional moisture profiles from radiosondes.

The AMDAR Panel can help with organising regional or national AMDAR programmes by: Working with the NMHS to evaluate the potential for developing a national AMDAR program; Assisting with technical support and training; Providing technical material and manuals needed to establish a National or Regional AMDAR program; and Working with the NMHS and the airline to create the necessary documents and infrastructure agreements. For More Information: Developing Regional or National AMDAR Programmes

Distribution map of the average number of aircraft reports decoded per 24- hour periods in 10 deg. lat-lon boxes. Courtesy Environment Canada. Data Availability