In-situ aircraft data from the MOZAIC Database:data set description

Data set source
Information on available Data
Data Processing
Data format
Data selection page

Ozone, water vapour and temperature from Airbus aircraft over the FASTEX domain (20N-90N ; 140W-40E)

Data set source:

These data were provided by the 'Measurement of OZone by Airbus In-service airCraft' (MOZAIC) program.
Contact: Dr Alain Marenco, MOZAIC Programme Coordinator, Laboratoire d'Aerologie 14 Avenue Edouard Belin, 31400 Toulouse Cedex, France.

The MOZAIC system has been developed for automatic ozone, water vapour and temperature measurements during in service flights aboard A340 aircraft. MOZAIC is an European cooperation between the 'Laboratoire d'Aerologie' of CNRS (Centre National de la Recherche Scientifique) and Airbus Industrie. Several organizations participate to this project : the KFA (Kennforschungsanstalt) Julich and the Max Planck Institut (MPI) Mains in Deutschland, Meteo France, the Cambridge University in England and the Tenerife University in Portugal.

For more information on the MOZAIC Program and the MOZAIC Data Base, see the MOZAIC site .

Information on available data in the FASTEX Central Archive

  • Available since :11 DEC 1998 - Last Updated: 11 DEC 1998
  • Time Coverage (YYYYMMDD): between 19970101 and 19970301
  • Geographic Coverage (decimal degrees): latitude between 20 and 72, longitude between -123 and 40
  • Number of observations: 122500 (about 2000 messages a day)
    Daily detailed information is available .

  • Data Processing

    Files are in three parts:
    1. Ascending part:
      The averaged values with altitude interval of about 150 m.
    2. Crusing altitude:
      The averaged values with a gap of 1 minute.
    3. Descending profile:
      Averages values with altitude interval of about 150 m.

    Here is the way the files are built:

    1. All along the flight, two tests are done on altitude and time. We read each record which gives values: H1, for the altitude, and T1 for the time.(normaly every 4 seconds), then we read the following records and do the test:
      if (|H1-H| >= 150 meters or |T1-T| >= 60 seconds) then
      we make the averages of the i values of the interval
      and so on.

      The box size is 150 m height x 60 seconds time
      Then the profiles are built with mean values on intervals of either 150 meters or 60 seconds.

    2. With regard to the RH validity:
    3. RH=0 no data, these values are excluded for the calculation of the averaged values.
    4. RH=1,2,3 these values are taken in account for the calculation of the average.
    5. RH=1 measurement ok
    6. RH=2 Below detection limit of RH
    7. RH=3 Data have limited reliability
    8. If no measure is available, the averaged humidity takes the default value -999.9.
      Remarks :
    1. "baro altitude" is the geopotential height computed from the pressure measurement using the ICAO standard atmospheric profile. "baro altitude" data contain the same information as "pressure" data
    2. "radio altitude" is the altitude above surface and is switched on only during take-off and landing phases.
    3. Wind direction is the direction from which the wind is blowing. Origin is North. The direction increases clockwise. As a result, wind blowing from North has direction 0 degree, wind blowing from East has direction 90 degrees.
    4. static temperatures : "A340 stat. temp." is provided by the aircraft computer. "static temp." is computed from the MOZAIC sensors.
    5. H2O Relative Humidity (with respect to liquid water) is derived from the output of the capacitive sensor, the pressure and temperature conditions in the measuring cell (Rosemount housing) together with static pressure and temperature conditions. H2O mass mixing ratio is computed from the Relative humidity, the static temperature and pressure. It therefore does not contain any new piece of information.
    6. H2O mixing ratio is computed from the Goff-Gratch formula.

    Data format

    ASCII Files including these parameters:
    position (lat,long,altitude), date and time, air temperature, wind speed and direction, ozone mixing ratio, Relative humidity.

  • 1 st line: Coded for the three groups participating in the file processing. The version number should be increased by 0.1, when a modified file is put in the data base.
    DD:day; MM:month; YY:year.
  • 2 nd line: Information on the flight.
    flight: MXXXXXXX on yy-mm-dd NL=XX from -> to NL=XX
    XX number of lines in the file
  • The format (fortran 77 ANSI norm) is:
         +   1x,i7,1x,f6.2,2(1x,f7.2),1x,f7.2,1x,f7.2,1x,i5,1x,f5.1,
         +   1x,f6.1,1x,i2,1x,i3,1x,f7.3)
    The fields in the record are:
    Data UnitFormatPrecision Default value
    latitude deg/frac f6.2 0.01 -99.99
    longitude deg/frac f7.2 0.01 -999.99
    date yymmdd i6.6 0 999999
    time hhmmss i6.6 0 999999
    baro altitude m f8.1 0.3 -99999.9
    radio altitude m f7.1 0.1 -9999.9
    pressure Pa i7 10 -999999
    A340. stat. temp. degC f6.2 0.25 -99.99
    A340.air.speed m/s f7.2 0.01 -999.99
    A340.ground.speed m/s f7.2 0.01 -999.99
    wind direction deg/frac f7.2 0.1 -999.99
    wind speed m/s f7.2 0.01 -999.99
    ozone mixing ratio ppbv i5 1 -9999
    static temp. degC f5.1 0.1 -99.9
    Relative humidity % f6.1 0.1 -999.9
    RH validity 0,1,2,3 i2 0 -9
    RH accuracy % i3 - -99
    H2O mixing ratio g/kg f7.3 0.01 -99.999
    Latitudes, between -90.00 and 90.00 deg.
    Longitudes, between -180.00 and 180.00 deg.
    H2O mixing ratio is a computed field.


    Marenco Alain et al.(1998): Measurement of ozone and water vapor by Airbus in-service aircraft: The MOZAIC airborne program, An overview. Journal of Geophysical research -Atmospheres , MOZAIC Special Section October 98
    MOZAIC site:
    Updated: 14 Dec 1998

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