Total HCHO column data record
Description
Total HCHO column data record provides long-term information about vertical column densities of formaldehyde in the atmosphere. It has been reprocessed with the latest algorithm version (see below).
Type
Data record
Satellites and instruments
GOME-2/Metop-A and GOME-2/Metop-B
Algorithm version
GDP 4.8
Time period
- 23/01/2007 - 16/11/2016 (GOME-2/Metop-A)
- 13/12/2012 - 16/11/2016 (GOME-2/Metop-B)
Theoretical basis
The retrieval of the product is based on GOME-2 (ir)radiance measurements in the wavelength region of 328.5-346 nm.
Processing
DLR generates vertical column products with Universal Processor for UV/VIS Atmospheric Spectrometers (UPAS), inside which the GOME Data Processor (GDP) operational algorithm is the baseline algorithm for the trace gas column retrievals from GOME-2. The latest GDP 4.8 uses an optimised DOAS (Differential Optical Absorption Spectroscopy) algorithm to determine the trace gas slant column. The DOAS slant column fitting is followed by Air Mass Factor (AMF) conversions to generate vertical columns.
Units and spatial resolution
HCHO columns are given as vertical column densities (molecules/cm2).
GOME-2/Metop-A has 24 forward-scan pixels with a nominal resolution of 40 km x 40 km, and 8 back-scan pixels with a nominal resolution of 120 km x 40 km.
GOME-2/Metop-B has 24 forward-scan pixels with a nominal resolution of 80 km x 40 km, and 8 back-scan pixels with a nominal resolution of 240 km x 40 km.
Both forward- and back-scan pixels are processed and written to the product.
Validation
This product has been validated by Belgian Institute for Space Aeronomy (BIRA-IASB). The validation is based on an end-to-end approach, that has been developed to evaluate independently all critical components of the level-1-to-2 retrieval chain, using correlative observations performed by ground-based and satellite instruments.Visit BIRA HCHO validation page for further information.
Archiving and dissemination
This product is archived at the DLR and available via data record access page.
File format
The product is delivered in HDF5 format, each file containing one satellite orbit (sunlit portion).
Documents
GOME-2 pages at DLR: ATMOS