High-resolution ozone profile data record
Description
The high-resolution ozone profile data record provides an ozone profile from the GOME-2 nadir scanning mode, the full error covariance matrix, the retrieval noise covariance matrix, the a priori profile, the averaging kernels and the retrieved auxiliary parameters, like surface or cloud albedo. Also included are: geo-location, the specific spectral windows used and retrieval diagnostics, like the number of iterations and spectral fit indicators. DOI: 10.15770/EUM_SAF_AC_0037
Type
Data record
Satellites and instruments
GOME-2/Metop-A and GOME-2/Metop-B
Algorithm version
2.00
Time period
- 23/01/2007 - 31/12/2018 (GOME-2/Metop-A)
- 12/12/2012 - 31/12/2018 (GOME-2/Metop-B)
Theoretical basis
Global Ozone Monitoring Experiment-2 (GOME-2) measures the radiance spectrum of sunlight scattered from the atmosphere in the (UV) wavelength region 260-330 nm. The absorption of ozone decreases with increasing wavelength. This differential absorption makes it possible to derive the vertical distribution of ozone in the atmosphere from the measured UV spectrum.
Processing
At KNMI, Ozone ProfilE Retrieval Algorithm (OPERA) iteratively finds the vertical ozone profile best matching the GOME-2 reflectance using optimal estimation. The forward model is based on LidortA and uses an externally prescribed instrument response slit function. The a priori ozone climatology is (currently) based on McPeters/Labow/Logan. The surface pressure and the vertical temperature profile come from operational ECMWF forecasts. Special adaptations have been made to handle spikes in the measured radiance spectrum in the South Atlantic Anomaly.
Units and spatial resolution
The vertical ozone profiles are given as partial ozone columns in Dobson Units (DU) in 40 layers from the surface up to 0.001 hPa. The ground pixel size corresponds to the footprint of the Band-1b integration time: 40 km × 80 km (23/01/2007 – 16/07/2013) and 40 km × 40 km (16/07/2013 – 31/12/2018) for Metop-A and 40 km × 80 km for Metop-B.
Validation
This product is validated by DWD (Germany) and KMI (Belgium). The validations are based on detailed comparisons of the operational retrieved profiles from GOME-2 satellite data with ground-based measurements (balloon soundings, lidar and microwave radiometer measurements). Visit AC SAF ozone profiles validation website for further information.
Archiving and dissemination
This product is archived at the FMI and available via data record access page.
File format and size
This product is delivered in NetCDF-4 format, each file containing one satellite orbit (sunlit portion). The size of a single product file is about 370 MB.