Observations From the Global AMDAR Program Presentation to WMO TECO-2005 4-7 May 2005 by

Observations From the Global AMDAR Program

Presentation to

WMO TECO-2005 4-7 May 2005

by

Jeff SticklandTechnical Coordinator, WMO AMDAR Panel

System Description

Aircraft Meteorological Data RelayAMDAR =

AMDAR is:

• A fully automated upper air observing system;

• 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;

– standard installed high quality sensors for wind, temperature and turbulence plus height (pressure), time and position;

• Uses existing aircraft and airline infrastructure including:

– onboard avionics and communications hardware and software;

– Airlines normally use the international communications system called Aircraft Communications and Reporting System (ACARS). Global services are provided by 2 companies – ARINC and SITA.

System Description (cont.)

• Humidity sensors are being developed and will be added in the future to SOME aircraft;

– airline ground-based data processing systems;

• The only additional requirement to make AMDAR work is special AMDAR software installed in the aircraft avionics or communications hardware;

• No new hardware is required on the aircraft;

TYPICAL AMDAR INSTALLATION

=

FITTED WITH EXISTING SENSORS

+ AVIONICS HARDWARE

+ AVIONICS SOFTWARE

+ COMMUNICATIONS

AMDAR SOFTWARE+

AMDAR System StructureAMDAR System Structure Operational, Reporting, Monitoring & Feedback Operational, Reporting, Monitoring & Feedback

GTS

NMS

QEv Centre

Ground-basedData Processing

System(s)

RegionalData Optimising

Centre

FlightControl

SITA/ARINCNetwork

AirlinesUplinkingSystems

Co-ordinator

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.

Operational Cost compared to radiosonde is 1%

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

To help provide a more comprehensive assessment of the atmosphere for local modelling research, local forecasting, etc;

For forecast verification;

To meet the NWP community’s requirement for greater quantities and improved coverage of relevant upper air data;

Data RequirementsDesirable Horizontal Spatial and Temporal Density:

1 profile on 250 km grid at 3 hourly intervals

Element Unit Range Outputresolution

Desiredaccuracy

PressureAltitude

Foot (ft) -1000 to 50000 10 100(1)

Static AirTemperature

oC -99 to 99 0.1 0.5(2)

WindDirection

O from true N 1 to 360 1 Note (2,3)

Wind Speed Knot (kt) 0 to 800 1 Note (2,3)Latitude Degree:minute 90:00S to 90:00N 1.0min Note (4)Longitude Degree:minute 180:00E to

180:00W1.0min Note (4)

Time (UTC) Hour:Minute:Second

00:00:00 to23:59:59

1 min 1s

Notes:

(1) required to preserve temperature accuracy(2) WMO requirement for NWP in troposphere(3) 2ms-1 (4kt) vector error(4) 5Nm equivalent (specified for ASDAR)

BASIC Data

Element Unit Range Output

resolution Desired accuracy

Maximum wind kt 0 to 800 1 4 Turbulence (g) g (4) -3 to 6 0.1 0.15(1) Turbulence(DEVG) ms-1 0 to 20 0.25 0.5(1) Turbulence(EDR) m2/3s-1 0 to 1 0.05 0.1(1) Humidity(RH) % 0 to 100 1 5(2) Humidity (dew pt) oC -99 to +49 0.1 Note 5 Humidity(mixing ratio)

gram/kg 0 to 100 0.001 1:103

(measurement)(3) Notes: (1) Determined by output categories required (2) WMO requirement for NWP in troposphere (3) To meet stratospheric humidity requirement (4) Acceleration due to gravity. ‘Zero’ reference on aircraft is usually +1. (5) Equivalent to 5% RH error.

Additional Data

Data Requirements (cont.)

Mandatory and Optional Reported Elements

Element Mandatory/Optional Requires AdditionalOnboard Processing

Aircraft identifier MPhase of flight MLatitude MLongitude MDay & time of observation MPressure altitude MStatic air temperature MWind direction MWind speed MMaximum wind MRoll & pitch angle flag M *Humidity O *Turbulence O *Icing O *

24 Hour Global Coverage

13 April 2005

Courtesy NOAA FSL

24 Hour AMDAR Profiles

13 April 2005

Courtesy NOAA FSL

E-AMDAR Temperature Quality

Frequency distribution of the mean temperature difference (OBS–Background)

KNMI QEV Report - April - June 2001

E-AMDAR Wind Speed Quality

Frequency distribution of the mean wind speed difference (OBS–

Background) KNMI QEV Report - April - June 2001

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

LIT WVSS-2 vs. Raob Comparison

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.

Mixing ratio (g/kg) for 3 aircraft on ascent with 62 minutes of each other 3/11/05) Criteria Range of Height N453 N411 N402 {range of (1000’s ft) (feet) (0941Z) (1006Z) (1043Z) mixing ratio} h < 1 760 – 960 4.3 4.8 4.4 – 4.3 [ 0.5 ] 1 < h < 2 1010 – 1940 4.3 – 4.1 4.7 – 4.3 4.2 – 3.8 [ 0.9 ] 2 < h < 3 2120 – 2950 3.8 – 3.2 4.1 – 3.8 3.7 – 3.6 [ 0.9 ] 3 < h < 3.7 3120 – 3630 3.0 3.6 – 3.2 3.5 – 3.4 [ 0.5 ] 4.5 < h < 5.1 4530 – 5070 2.8 3.0 3.3 [ 0.5 ] 6.0 < h < 7.0 6070 – 6490 2.8 2.6 2.5 [ 0.3 ] 7.1 < h < 8.3 7170 – 8230 2.6 – 2.3 2.4 2.4 – 2.1 [ 0.5 ] 9.4 < h < 10.8 9400 – 10740 1.6 1.4 1.6 – 1.4 [ 0.2 ] 11.2 < h < 12 1122 0 – 11930 1.4 1.3 1.3 [ 0.1 ] 12.1 < h < 13 12140 – 12930 1.1 .84 – .75 1.3 – 1.2 [ 0.55 ] 14 < h < 18 14110 – 17970 .88 - .49 .61 - .38 .82 - .41 [ 0.5 ] 22.0 < h < 26 22440 – 26000 .30 - .28 .04 - .03 .22 - .20 [ 0.27 ]

Relative Humidity (RH) for 3 aircraft on ascent with 62 minutes of each other 3/11/05) Criteria Range of Height N453 N411 N402 {range of RH} (1000’s ft) (feet) (0941Z) (1006Z) (1043Z) (%) h < 1 760 – 960 85.2 - 84.1 95.1 84.9 – 81.2 [ 13.9 ] 1 < h < 2 1010 – 1940 83.2 – 81.9 89.1 – 79.1 80.3 – 79.8 [ 9.3 ] 2 < h < 3 2120 – 2950 77.1 – 70.7 76.8 – 73.4 87.5 - 78.4 [ 16.8 ] 3 < h < 3.7 3120 – 3630 71. 0 – 67.9 77.8 – 71.3 91.9 - 88.1 [ 24.0 ] 4.5 < h < 5.1 4530 – 5070 83.9 83.6 – 78.4 101.6 [ 23.2 ] 6.0 < h < 7.0 6070 – 6490 91.9 82.8 88.0 [ 9.1 ] 7.1 < h < 8.3 7170 – 8230 100.5 – 97.7 88.6 97.7 – 95.7 [ 11.9 ] 9.4 < h < 10.8 9400 – 10740 87.9 – 76.7 67.4 87.1 – 80.2 [ 20.5 ] 11.2 < h < 12 1122 0 – 11930 107.8 – 95.7 89.4 – 82.8 82.6 – 74.0 [ 33.8 ] 12.1 < h < 13 12140 – 12930 77.2 47.8 – 45.5 88.3 – 84.7 [ 40.5 ] 14 < h < 18 14110 – 17970 76.8 – 61.5 48.4 – 39.8 83.0 – 64.7 [ 34.6 ] 22.0 < h < 26 22440 – 26000 98.2 – 82.3 7.1 – 6.0 67.2 – 52.0 [ 92.2 ]

Dew point for 3 aircraft on ascent with 62 minutes of each other 3/11/05) Criteria Range of Height N453 N411 N402 {range of (1000’s ft) (feet) (0941Z) (1006Z) (1043Z) mixing ratio} h < 1 760 – 960 1.5 to 1.4 3.0 1.8 to 1.4 [ 1.6 ] 1 < h < 2 1010 – 1940 1.2 to 0.2 2.6 to 0.9 0.8 to -0.8 [ 3.4 ] 2 < h < 3 2120 – 2950 -0.9 to -3.6 0.1 to -1.2 -1.6 to -2.0 [ 3.7 ] 3 < h < 3.7 3120 – 3630 -4.6 to -4.8 -2.1 to -3.9 -2.5 to -3.1 [ 2.7 ] 4.5 < h < 5.1 4530 – 5070 -6.4 -5.2 to -5.5 -4.0 [ 2.4 ] 6.0 < h < 7.0 6070 – 6490 -6.4 -8.0 -8.4 [ 2.4 ] 7.1 < h < 8.3 7170 – 8230 -8.4 to -10.4 -9.6 -9.4 to -11.5 [ 3.1 ] 9.4 < h < 10.8 9400 – 10740 -15.4 to -15.9 -17.3 -15.6 to -17.6 [ 2.2 ] 11.2 < h < 12 1122 0 – 11930 -17.9 to -18.1 -18.7 to -18.9 -18.8 to -19.0 [ 1.1 ] 12.1 < h < 13 12140 – 12930 -21.3 -24.1 to -25.7 -19.1 to -20.4 [ 5.0 ] 14 < h < 18 14110 – 17970 -24.5 to -32.3 -28.6 to -34.7 -25.2 to -34.1 [ 10.2 ] 22.0 < h < 26 22440 – 26000 -39.4 to -40.5 -56.6 to -58.2 -42.1 to -44.3 [ 18.8 ]