Dataset
STFC RAL methane retrievals from IASI on board MetOp-A, version 1.0
Abstract
The Infrared Atmospheric Sounding Interferometer (IASI) methane dataset contains height-resolved and column-averaged volume mixing ratios of atmospheric methane (CH4). It also includes column-averaged water vapour (H2O), a scale factor for the HDO volume mixing ratio profile, surface temperature, effective cloud fraction, effective cloud-top pressure and scale factors for two systematic residual spectra which are jointly retrieved from the spectral range 1232.25-1290.00 cm-1 by the Rutherford Appleton Laboratory (RAL) IASI optimal estimation methane retrieval scheme. The dataset additionally contains selected a priori values and uncertainties adopted in the optimal estimation scheme and retrieval output diagnostics such as the retrieval cost and the averaging kernels.
This work was funded by the National Centre for Earth Observation (NCEO) under the UK Natural Environment Research Council (NERC) with additional funding from EUMETSAT.
Data were produced by the Science and Technology Facilities Council (STFC) Remote Sensing Group (RSG) at the Rutherford Appleton Laboratory (RAL).
This is version 1.0 of this dataset and is the first to be released.
Details
| Previous Info: |
No news update for this record
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| Previously used record identifiers: |
No related previous identifiers.
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| Access rules: |
Access to these data is available to any registered CEDA user. Please Login or Register for a CEDA account to gain access.
Use of these data is covered by the following licence(s): http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. |
| Data lineage: |
Data produced by the Rutherford Appleton Laboratory (RAL) Remote Sensing Group (RSG). The development of the Infrared Atmospheric Sounding Interferometer (IASI) offline thermal-IR methane retrieval was funded by the Natural Environment Research Council (NERC) through its National Centre for Earth Observation (NCEO) with additional funding from EUMETSAT. |
| Data Quality: |
See dataset associated documentation
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| File Format: |
Files are formatted in netCDF4.
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Process overview
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: Metop-A |
Computation Element: 1
| Title | STFC RAL IASI methane processor |
| Abstract | Retrieval of methane using the STFC RAL IASI methane processor. Full retrieval diagnostic information including averaging kernels, estimated error and retrieved cloud parameters is produced. |
| Input Description | None |
| Output Description | None |
| Software Reference | None |
| Output Description | None |
- units: 1e-6
- long_name: A priori column-averaged dry-air mole fraction of atmospheric methane (ppmv).
- var_id: ap_ch4_xvmr
- units: 1e-6
- long_name: A priori dry-air mole fraction of atmospheric methane (ppmv).
- var_id: ap_ch4_vmr
- units: 1e-6
- long_name: A priori error on retrieved dry-air mole fraction of atmospheric methane (ppmv).
- var_id: ap_ch4_vmr_err
- units: K
- long_name: A priori surface temperature (K).
- var_id: ap_surface_temperature
- units: 1e-6
- long_name: Averaging kernel for column-averaged mixing ratio (ppmv).
- var_id: ak_xvmr
- units: 1e-6
- long_name: Averaging kernel for profile mixing ratios (ppmv).
- var_id: ak_vmr
- units: 1e-6
- long_name: Column-averaged equivalent N2O (modelled).
- var_id: xn2o_eql
- var_id: day
- long_name: Day of the month (1-31).
- long_name: Errors on residual scale factors.
- var_id: rsf_err
- units: 1e-6
- long_name: Estimated error on retrieved methane profile (ppmv).
- var_id: ch4_vmr_err
- units: 1e-6
- long_name: Estimated error on the retrieved column-averaged mixing ratio (ppmv).
- var_id: ch4_xvmr_err
- var_id: pixel_number
- long_name: IASI detector pixel (0-3).
- var_id: month
- long_name: Month of the year (1-12).
- long_name: Number of scan line (0=start of orbit).
- var_id: scan_line
- long_name: Position within scan line (0-29).
- var_id: scan_position
- units: hPa
- long_name: Pressure levels of true state in provided averaging kernels.
- var_id: mod_plev
- units: hPa
- long_name: Pressures of retrieval levels (hPa) for which averaging kernels are provided.
- var_id: ret_plev_ak
- long_name: Retrieval cost function value.
- var_id: chim
- units: hPa
- long_name: Retrieval pressure levels (hPa).
- var_id: ret_plev
- units: 1e-6
- long_name: Retrieved column-averaged dry-air mole fraction of atmospheric methane (ppmv).
- var_id: ch4_xvmr
- units: 1e-6
- long_name: Retrieved column-averaged mole fraction of atmospheric water vapour in air (ppmv).
- var_id: h2o_xvmr
- units: 1e-6
- long_name: Retrieved dry-air mole fraction of atmospheric methane (ppmv).
- var_id: ch4_vmr
- units: 1
- var_id: cloud_fraction
- long_name: Retrieved effective cloud fraction.
- units: hPa
- long_name: Retrieved effective cloud-top pressure (hPa).
- var_id: cloud_pressure
- units: K
- standard_name: surface_temperature
- var_id: surface_temperature
- long_name: Retrieved surface temperature (K).
- long_name: Scale factors for the mean fit and across-track residual patterns.
- var_id: rsf
- units: degrees
- standard_name: sensor_zenith_angle
- long_name: Sensor zenith angle (degrees).
- var_id: vza
- units: degrees
- var_id: sza
- standard_name: solar_zenith_angle
- long_name: Solar zenith angle (degrees).
- units: km
- long_name: Spatially interpolated ECMWF surface altitude (km).
- var_id: ecmwf_alt
- long_name: Surface Temperature
- names: Surface Temperature
- units: hPa
- standard_name: surface_air_pressure
- var_id: surface_pressure
- long_name: Surface pressure (hPa) used in the retrieval.
- long_name: The average number of retrieval steps (number of calls to the forward model).
- var_id: nstep
- units: msec
- long_name: Time of day in msec since midnight (UTC).
- var_id: time_in_msec
- var_id: year
- long_name: Year.
Co-ordinate Variables
- units: degrees_north
- standard_name: latitude
- var_id: lat
- long_name: Latitude (degrees_north)
- units: degrees_east
- standard_name: longitude
- var_id: lon
- long_name: Longitude (degrees east).
Temporal Range
2007-05-31T23:00:00
2016-12-31T23:59:59
Geographic Extent
90.0000° |
||
-180.0000° |
180.0000° |
|
-90.0000° |