Observations From the Global AMDAR Programme

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Observations From the Global AMDAR
Programme Presentation to WMO TECO-2006 4-6
December 2006 by Michael BerechreeTechnical
Coordinator, WMO AMDAR Panel
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System Description

• 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

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System Description

• 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.

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System Description
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Data Requirements
Desirable Horizontal Spatial and Temporal
Density 1 profile on 250 km grid at 3 hourly
intervals
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Data Requirements
Additional Data
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Mandatory and Optional Reported Elements
Element Mandatory/Optional Requires
Additional (M/O) 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 YES Hum
idity O YES Turbulence O YES Icin
g O YES
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Why is AMDAR Data Needed?

• To meet the NWP communitys requirement for
  greater quantities and improved coverage of
  relevant upper air data

• For forecast verification

• 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

• 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.

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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

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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
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• 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

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Why is AMDAR Data Needed?
The benefits of AMDAR data are global and large
for forecasts out to 48 hour.
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Why is AMDAR Data Needed?
The benefits of AMDAR data are global and large
for forecasts out to 48 hour.
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Growth in AMDAR data
Over 200,000 high quality observations per day
being exchanged on the GTS Over 2,800 reporting
aircraft world wide
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24 Hour AMDAR Coverage 30 November 2006
Courtesy NOAA ESRL/GSD
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24 Hour AMDAR Profiles 30 November 2006
Courtesy NOAA ESRL/GSD
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Data Availability
Distribution map of the average number of
aircraft reports decoded per 24-hour periods in
10 deg. lat-lon boxes. Courtesy Environment
Canada.
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AMDAR Temperature and Wind Profiles
Courtesy NOAA ESRL/GSD
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Data Quality

• 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 2006.
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Data Quality
Frequency distribution of the mean temperature
difference (OBSBackground) KNMI QEV Report
January March 2004
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Data Quality
Frequency distribution of the mean wind speed
difference (OBSBackground) KNMI QEV Report
January March 2004
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AMDAR Humidity Measurement
SpectraSensors, WVSS-II Near-Infrared
Absorption Spectrometer Based on Tunable Diode
Laser Heated Inlet Hose Output Water
Vapor Mass Mixing Ratio
Air Sampler
Cylindrical Sampling Tube
24 cm
SEB
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AMDAR Humidity Measurement
FWD
Skin
SEB
Hose, Non-Heated
Hose, Heated
Air Sampler
Air Sampler
Frame
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Airbus Solution for AMDAR
AMDAR data as per ARINC 620v4 Supplement 5
28 VDC
SEB
ARINC bus 429
Hoses
Probe
AOC
AOC
ATC
ATC
Step 2
AMDAR
Weather
WVSS-II
VHF HF SATCOM
Flight Management System
Aircraft Interface Host Platform
Hardware
Step 1
Air Traffic Service Unit
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AMDAR Humidity Measurement
Recent comparison of WVSS-2 Water Vapour Profile
and Radiosonde profile, November 2006
Courtesy NOAA ESRL/GSD
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AMDAR Humidity Measurement
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.
Relative Humidity differences between WVSS-II and
Radiosondes for 2-week test period
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Developing Regional or National AMDAR Programmes

• 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 http//www.wmo.int/web/aom/a
  mprog/amprog.html/

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