Dataset
ESA Greenhouse Gases Climate Change Initiative (GHG_cci): Column-averaged CH4 from SCIAMACHY generated with the IMAP-DOAS algorithm (CH4_SCI_IMAP), v7.2
Abstract
The CH4_SCI_IMAP dataset is comprised of level 2, column-averaged dry-air mole fractions (mixing ratios) of methane (CH4). It has been produced using data acquired from the SWIR spectra (channel 6) of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on board the European Space Agency's (ESA's) environmental research satellite ENVISAT using the IMAP-DOAS algorithm. It has been generated as part of ESA Greenhouse Gases Climate Change Initiative (GHG_cci) project. This version of the dataset is v7.2 and forms part of the Climate Research Data Package 4.
The IMAP-DOAS algorithm has been developed at the University of Heidelberg and SRON, and has been applied here to the SCIAMACHY data. This procedure and the algorithms validity are thoroughly described in Frankenberg et al (2011). A second product is also available which has been generated using the Weighting Function Modified DOAS (WFM-DOAS) algorithm.
The data product is stored per orbit in a single NetCDF4 file. Retrieval results are provided for the individual SCIAMACHY spatial footprints, no averaging having been applied. The product file contains the key products and information relevant to using the data, such as the vertical layering and averaging kernels. For further details on the product, including the IMAP algorithm and the SCIAMACHY instrument, please see the associated product user guide (PUG) or the Algorithm Theoretical Basis Document.
Details
| Previous Info: |
2018-03-19 Users are encouraged to register their interest in this project at: http://cci.esa.int/content/sign-ecv-mailing-list 2018-03-19 Users are encouraged to register their interest in this project at: http://cci.esa.int/content/sign-ecv-mailing-list |
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| Previously used record identifiers: |
No related previous identifiers.
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| 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: https://artefacts.ceda.ac.uk/licences/specific_licences/esacci_ghg_terms_and_conditions.pdf. 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
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Related Documents
Process overview
Instrument/Platform pairings
| Envisat - SCIAMACHY | Deployed on: Envisat |
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: Envisat |
| Output Description | None |
- units: 1e-9
- long_name: 1-sigma uncertainty of the retrieved column-average dry-air mole fraction of atmospheric methane
- var_id: xch4_uncertainty
- names: 1-sigma uncertainty of the retrieved column-average dry-air mole fraction of atmospheric methane
- units: 1
- long_name: Chi-squared
- var_id: chi2_co2
- names: Chi-squared
- units: m-2
- long_name: Dry airmass per layer
- var_id: dry_airmass_layer
- names: Dry airmass per layer
- units: cm-2
- long_name: ECMWF H2O vertical column density
- var_id: h2o_ecmwf
- names: ECMWF H2O vertical column density
- units: m
- standard_name: height
- long_name: Height
- var_id: surface_elevation
- names: height, Height
- units: 1
- var_id: xch4_quality_flag
- long_name: Retrieval quality flag
- names: Retrieval quality flag
- units: degrees
- long_name: Sensor zenith angle
- standard_name: sensor_zenith_angle
- var_id: sensor_zenith_angle
- names: Sensor zenith angle, sensor_zenith_angle
- units: degrees
- long_name: Solar zenith angle
- var_id: solar_zenith_angle
- standard_name: solar_zenith_angle
- names: Solar zenith angle, solar_zenith_angle
- units: Kelvin
- var_id: surface_temperature
- long_name: Surface temperature
- names: Surface temperature
- units: 1e-9
- var_id: ch4_profile_apriori
- long_name: a priori profile of dry-air mole fraction of atmospheric methane (ppb)
- names: a priori profile of dry-air mole fraction of atmospheric methane (ppb)
- units: 1e-6
- long_name: column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) as used in XCH4 proxy
- var_id: xco2_retrieved
- names: column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) as used in XCH4 proxy
- units: 1e-6
- long_name: column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker2015
- var_id: xco2_CT2015
- names: column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker2015
- units: 1e-6
- long_name: column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from MACC(downloaded August 2016 from portal)
- var_id: xco2_macc
- names: column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from MACC(downloaded August 2016 from portal)
- units: 1e-9
- var_id: xch4
- long_name: column-average dry-air mole fraction of atmospheric methane (ppb)
- names: column-average dry-air mole fraction of atmospheric methane (ppb)
- units: 1e-9
- long_name: column-average dry-air mole fraction of atmospheric methane (ppb), includes tentative bias correction using H2O columns
- var_id: xch4_raw
- names: column-average dry-air mole fraction of atmospheric methane (ppb), includes tentative bias correction using H2O columns
- units: 1e-9
- long_name: column-average dry-air mole fraction of atmospheric methane (ppm) from the last version IMAP v71 (CT2011 used and older bias correction)
- var_id: xch4_v71
- names: column-average dry-air mole fraction of atmospheric methane (ppm) from the last version IMAP v71 (CT2011 used and older bias correction)
- units: 1
- long_name: normalized column averaging kernel
- var_id: xch4_averaging_kernel
- names: normalized column averaging kernel
- units: hPa
- long_name: pressure levels
- var_id: pressure_levels
- names: pressure levels
- units: 1
- long_name: pressure weights
- var_id: pressure_weight
- names: pressure weights
- units: 1e-6
- long_name: prior column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker 2011
- var_id: xco2_prior
- names: prior column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker 2011
- units: 1e-9
- long_name: prior column-average dry-air mole fraction of atmospheric methane (ppb)
- var_id: xch4_prior
- names: prior column-average dry-air mole fraction of atmospheric methane (ppb)
Co-ordinate Variables
- units: degrees_north
- standard_name: latitude
- var_id: latitude
- long_name: latitude
- names: latitude
- units: degrees_east
- standard_name: longitude
- var_id: longitude
- long_name: longitude
- names: longitude
- long_name: time
- standard_name: time
- var_id: time
- names: time
Temporal Range
2003-01-08T00:00:00
2012-04-08T22:59:59
Geographic Extent
90.0000° |
||
-180.0000° |
180.0000° |
|
-90.0000° |