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ESA Greenhouse Gases Climate Change Initiative (GHG_cci): Column-averaged CH4 from SCIAMACHY generated with the WFMD algorithm (CH4_SCI_WFMD), version 4.0

Update Frequency: Not Planned
Latest Data Update: 2017-07-20
Status: Completed
Online Status: ONLINE
Publication State: Published
Publication Date: 2018-03-19
Download Stats: last 12 months
Dataset Size: 3.21K Files | 3GB


The CH4_SCI_WFMD dataset comprises level 2, column-averaged dry-air mole fractions (mixing ratios) of methane (XCH4). It has been produced using data acquired from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on board the European Space Agency's (ESA's) environmental research satellite ENVISAT, as part of the ESA's Greenhouse Gases Climate Change Initiative (GHG_cci) project. This version of the data is version 4.0, and forms part of the Climate Research Data Package 4.

The Weighting Function Modified DOAS (WFMD) algorithm is a least-squares method based on scaling pre-selected atmospheric vertical profiles. A second product is also available, which has been generated from the SCIAMACHY data using the IMAP algorithm.

The data product is stored per day in separate NetCDF-files (NetCDF-4 classic model). The product files contain the key products and other information relevant for the use of the data e.g. the averaging kernels. Note that the results since November 2005 are considered to be of reduced quality in comparison to the earlier results because the extended-wavelength part (1590-1770 nm) of SCIAMACHY's channel 6, covering the methane 2v3 absorption band used for the methane retrieval, is subject to irreversible displacement damage induced by high energy solar protons, which occurs from time to time at individual detector pixels. Therefore several affected detector pixels had to be excluded for the time period since November 2005.

For further information on the product, including details of the WFMD algorithm and the SCIAMACHY instrument, please see the associated product user guide (PUG) or the Algorithm Theoretical Basis Documents.

Citable as:  ESA CCI GHG project team (2018): ESA Greenhouse Gases Climate Change Initiative (GHG_cci): Column-averaged CH4 from SCIAMACHY generated with the WFMD algorithm (CH4_SCI_WFMD), version 4.0. Centre for Environmental Data Analysis, date of citation.
Abbreviation: Not defined
Keywords: ESA, GHG, CCI, CH4, WFMD


Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence: When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

Data were processed by the ESA CCI GHG project team and supplied to CEDA as part of the ESA CCI Open Data Portal Project

File Format:
Data are in NetCDF format

Process overview

This dataset was generated by instruments deployed on platforms as listed below.

Instrument/Platform pairings

Envisat - SCIAMACHY Deployed on: Envisat

Mobile platform operations

Mobile Platform Operation 1 Mobile Platform Operation for: Envisat
Output Description


  • units: 1e-9
  • var_id: ch4_profile_apriori
  • long_name: a priori dry air mole fraction profile of atmospheric methane
  • units: m
  • standard_name: altitude
  • var_id: altitude
  • long_name: altitude
  • units: degree_north
  • long_name: corner latitudes
  • var_id: latitude_corners
  • units: degree_east
  • long_name: corner longitudes
  • var_id: longitude_corners
  • units: 1
  • long_name: ground scene number
  • var_id: scene_number
  • long_name: land mask
  • var_id: land_mask
  • units: 1
  • long_name: orbit number
  • var_id: orbit_number
  • units: hPa
  • long_name: pressure levels
  • var_id: pressure_levels
  • units: 1
  • long_name: pressure weight
  • var_id: pressure_weight
  • var_id: xch4_quality_flag
  • long_name: quality flag
  • units: degree
  • standard_name: sensor_zenith_angle
  • var_id: sensor_zenith_angle
  • long_name: sensor zenith angle
  • units: degree
  • long_name: solar zenith angle
  • var_id: solar_zenith_angle
  • standard_name: solar_zenith_angle
  • units: 1
  • long_name: state number
  • var_id: state_number
  • units: 1
  • long_name: surface albedo at 1560nm
  • var_id: surface_albedo_1560nm
  • units: 1
  • long_name: surface albedo at 1630nm
  • var_id: surface_albedo_1630nm
  • units: 1
  • long_name: surface albedo at 750nm
  • var_id: surface_albedo_750nm
  • var_id: h2o_column
  • units: g cm-2
  • long_name: vertical column of water vapour
  • units: 1
  • var_id: xch4_averaging_kernel
  • long_name: xch4 averaging kernel

Co-ordinate Variables

  • units: degree_north
  • standard_name: latitude
  • var_id: latitude
  • long_name: latitude
  • units: degree_east
  • standard_name: longitude
  • var_id: longitude
  • long_name: longitude
  • long_name: time
  • standard_name: time
  • var_id: time
Temporal Range
Start time:
End time:
Geographic Extent