acars: Aircraft Communications Addressing and Reporting System

General Data Description

ACARS stands for the Aircraft Communications Addressing and Reporting System, which is managed by Aeronautical Radio, Inc. (ARINC). ACARS is used by airlines to transmit a variety of proprietary air-to-ground communications. FSL uses the term ACARS to designate automated weather reports from commercial aircraft. These data are routed by several cooperating airlines to FSL, who decode and quality control the data. The data stream includes AMDAR data from many European and Asian air carriers. The AMDAR data are subjected to the same quality control and other processing by FSL as the ACARS data.

All data available are included in the "gec" (Global Earth Coverage) data stream. Data covering only the areas around each site are also available.

Further information about these data can be found at the FSL ACARS web page.

Measurement Description

The following measurements are available for all data streams:
  • missing minutes of input data
  • minimum and maximum date/time covered in file
For each observation:
  • latitude and longitude (degrees)
  • pressure altitude (meters MSL)
  • time of observation
  • temperature (Kelvin)
  • wind direction (degrees)
  • wind speed (meter/sec)
  • heading (degrees)
  • mach number
  • water vapor mixing ratio
  • relative humidity
  • dew point (Kelvin)
  • eddy dissipation rate (m^(2/3) s^-1)
  • peak vertical acceleration (meters/sec/sec)
  • peak vertical gust (meters/sec)
  • quality control and error indicators

Temporal Coverage

Data are available at the ARM Archive from 9/22/1998 to 5/31/2008

This data is no longer being actively collected by ARM. For current data, users may go to the MADIS archive at

Data Availability at the ARM Archive:
nsaacarsX1.a1: 9/22/1998 to 5/31/2008
sgpacarsX1.a1: 9/22/1998 to 5/31/2008
twpacarsX1.a1: 9/22/1998 to 5/31/2008
gecacarsX1.a1: 9/22/1998 to 2/23/2003.

Area Covered

gecacarsX1.a1 Covers the area with Lat (-90, 90) and Lon(-180, 180)
nsaacarsX1.a1 Covers the area with Lat (65, 80) and Lon(-175, -130)
sgpacarsX1.a1 Covers the area with Lat (31.941,41.00) and Lon(-103.561,-91.585)
twpacarsX1.a1 Covers the area with Lat (-20,20) and Lon(110,-80)

Data Stream Inputs

These data streams are directly provided from FSL.

Notification Form Link

ACARS Notification Form

Data Source

Forecast Systems Laboratory

Data User Notes

Check for Data Quality Reports about these data at the DQR Browse Web Page


ACARSAircraft Communications Addressing and Reporting System
FSLForecast Systems Laboratory
GECGlobal Earth Coverage
NSANorth Slope of Alaska
SGPSouthern Great Plains
TWPTropical Western Pacific

Citable References

Automated Meteorological Reports from Commercial Aircraft by Bill Moninger, Rich Mamrosh, and Pat Pauley (June 2002). Bulletin of the American Meteorological Society.