Total Ozone Mapping Spectrometer (TOMS)
Information updated on March 16, 2006, 3:32 pm GMT
General Data Description
Global data derived from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Earth Probe satellite, consisting of daily values of aerosol index, ozone and reflectivity remapped into a regular 1x1.25 deg grid. Users of these data should acknowledge the support of the NASA Goddard Ozone Processing Team.Data Stream Names
- toms - Total Ozone Mapping Experiment Spectrometer
netCDF File Header Description (Data Object Design File)
Measurement Description
OZONE
Ozone measurements are given in Dobson units and are integers with 3 significant figures. A Dobson Unit represents the physical thickness of the ozone layer if it were brought to the Earth's surface. A value of 300 Dobson units equals three millimeters or 1/10th of an inch. Missing values denote flagged data, i.e. data that could not be collected due to lack of sunlight or other problems.
AEROSOL INDEX
The data are an aerosol index formed directly from the measured radiances in two TOMS channels. Positive values generally represent absorbing aerosols (dust and smoke) while negative values represent nonabsorbing aerosols. The identification is not perfect because of geophysical reasons (e.g., aerosol too low to the ground).
REFLECTIVITY
The solar irradiance reflected up to a spacecraft from the surface of the Earth can be used to calculate reflectivity. Reflectivity calculated for specific bandwidths is needed for the calculation of total column ozone from TOMS instrument. Reflected radiation can come from two surfaces, the ground, and the tops of clouds. Reflectivity is determined from the measurements at 380 nm, or 360 nm in the case of Earth Probe. Clouds are clearly defined and recognizable in images produced using TOMS reflectivity data. Data are in percent.
Temporal Coverage
This data stream is replaced by gecomiX1.a1. See the Ozone Monitoring Instrument documentation
Area Covered
Data Stream Inputs
gectomsozoneX1.00
gectomsreflX1.00
Notification Form Link
Related Links
Contacts
- ARM Mentor Richard Wagener
- ARM Software Developer Laurie Gregory
Data Source
- Institution TOMS web page
Data User Notes
Check the Data Quality Reports for these data at The PIFCARDQR Web site DQR040920.2 discusses the changes to version 8 of the TOMS algorithm and questions whether data prior to September 2004 should be replaced with data based on the new algorith.
Beginning September 2004, the data are based on the version 8 TOMS algorithm. See Version 8 reference
Acronyms
GEC Global Earth Coverage TOMS Total Ozone Mapping Spectrometer
Citable References
Torres O., P.K. Bhartia, J.R. Herman and Z. Ahmad, Derivation of aerosol properties from satellite measurements of backscattered ultraviolet radiation. Theoretical Basis, J. Geophys. Res., 103, 17099-17110, 1998