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#
Dataset identifier: esacci.GHG.satellite-orbit-frequency.L2.CH4.SCIAMACHY.Envisat.IMAP.v7-2.r1
Data store: cciodp
How to open this dataset in AVL JupyterLab
cciodp_store = new_data_store('cciodp')
ds = cciodp_store.open_data('esacci.GHG.satellite-orbit-frequency.L2.CH4.SCIAMACHY.Envisat.IMAP.v7-2.r1')
Bounding box map#
cciodp_store = new_data_store('cciodp')
ds = cciodp_store.open_data('esacci.GHG.satellite-orbit-frequency.L2.CH4.SCIAMACHY.Envisat.IMAP.v7-2.r1')
Map tiles and data from OpenStreetMap, under the ODbL.
Basic information#
| Parameter | Value |
|---|---|
| Bounding box longitude (°) | -180.0 to 180.0 |
| Bounding box latitude (°) | -90.0 to 90.0 |
| Time range | 2003-01-08 to 2012-04-08 |
Click here for full dataset metadata.
Variable list#
Click on a variable name to jump to the variable’s full metadata.
| Variable | Long name | Units |
|---|---|---|
| solar_zenith_angle | Solar zenith angle | degrees |
| sensor_zenith_angle | Sensor zenith angle | degrees |
| pressure_levels | pressure levels | hPa |
| pressure_weight | pressure weights | 1 |
| xch4_raw | column-average dry-air mole fraction of atmospheric methane (ppb), includes tentative bias correction using H2O columns | 1e-9 |
| xch4 | column-average dry-air mole fraction of atmospheric methane (ppb) | 1e-9 |
| h2o_ecmwf | ECMWF H2O vertical column density | cm-2 |
| xch4_prior | prior column-average dry-air mole fraction of atmospheric methane (ppb) | 1e-9 |
| xco2_prior | prior column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker 2011 | 1e-6 |
| xco2_retrieved | column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) as used in XCH4 proxy | 1e-6 |
| xch4_uncertainty | 1-sigma uncertainty of the retrieved column-average dry-air mole fraction of atmospheric methane | 1e-9 |
| xch4_averaging_kernel | normalized column averaging kernel | 1 |
| ch4_profile_apriori | a priori profile of dry-air mole fraction of atmospheric methane (ppb) | 1e-9 |
| xch4_quality_flag | Retrieval quality flag | 1 |
| dry_airmass_layer | Dry airmass per layer | m-2 |
| surface_elevation | Height | m |
| surface_temperature | Surface temperature | Kelvin |
| chi2_ch4 | Chi-squared | 1 |
| chi2_co2 | Chi-squared | 1 |
| xco2_macc | column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from MACC(downloaded August 2016 from portal) | 1e-6 |
| xco2_CT2015 | column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker2015 | 1e-6 |
| xch4_v71 | column-average dry-air mole fraction of atmospheric methane (ppm) from the last version IMAP v71 (CT2011 used and older bias correction) | 1e-9 |
Full variable metadata#
solar_zenith_angle#
| Field | Value |
|---|---|
| standard_name | solar_zenith_angle |
| long_name | Solar zenith angle |
| units | degrees |
| comment | Solar zenith angle is the angle between the line of sight to the sun and the local vertical |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
sensor_zenith_angle#
| Field | Value |
|---|---|
| standard_name | sensor_zenith_angle |
| long_name | Sensor zenith angle |
| units | degrees |
| comment | Sensor zenith angle is the angle between the line of sight to the sensor and the local vertical |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
pressure_levels#
| Field | Value |
|---|---|
| long_name | pressure levels |
| comment | Pressure levels define the boundaries of the averaging kernel and mole fraction profile layers. Surface pressure is represented by the 1st element, i.e., profiles are ordered from surface to top of atmosphere. |
| units | hPa |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 39963 |
| shape | 3633, 11 |
| chunk_sizes | 3633, 11 |
| file_chunk_sizes | 3633, 11 |
| data_type | float32 |
| dimensions | sounding_dim, level_dim |
| file_dimensions | sounding_dim, level_dim |
pressure_weight#
| Field | Value |
|---|---|
| long_name | pressure weights |
| units | 1 |
| comment | Pressure weights are the layer dependent weights needed to apply the averaging kernels. |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 36330 |
| shape | 3633, 10 |
| chunk_sizes | 3633, 10 |
| file_chunk_sizes | 3633, 10 |
| data_type | float32 |
| dimensions | sounding_dim, layer_dim |
| file_dimensions | sounding_dim, layer_dim |
xch4_raw#
| Field | Value |
|---|---|
| long_name | column-average dry-air mole fraction of atmospheric methane (ppb), includes tentative bias correction using H2O columns |
| units | 1e-9 |
| comment | original (non-corrected) column-average dry-air mole fraction of atmospheric methane (XCH4) in ppp |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xch4#
| Field | Value |
|---|---|
| comment | Bias-corrected retrieved column-average dry-air mole fraction of atmospheric methane (XCH4) in ppp |
| long_name | column-average dry-air mole fraction of atmospheric methane (ppb) |
| units | 1e-9 |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
h2o_ecmwf#
| Field | Value |
|---|---|
| comment | ECMWF H2O vertical column density(from ECMWF) |
| units | cm-2 |
| long_name | ECMWF H2O vertical column density |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xch4_prior#
| Field | Value |
|---|---|
| long_name | prior column-average dry-air mole fraction of atmospheric methane (ppb) |
| units | 1e-9 |
| comment | a priori column-average dry-air mole fraction of atmospheric carbon methane (XCH4) in ppp |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xco2_prior#
| Field | Value |
|---|---|
| long_name | prior column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker 2011 |
| units | 1e-6 |
| comment | a priori column-average dry-air mole fraction of atmospheric carbon dioxide (XCO2) in ppm (to be used to replace the XCO2 rescaling factor if warranted) |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xco2_retrieved#
| Field | Value |
|---|---|
| long_name | column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) as used in XCH4 proxy |
| comment | retrieved column-average dry-air mole fraction of atmospheric carbon dioxide (XCO2) in ppm (not to be used for XCO2 interpretation, just for rescaling XCH4!) |
| least_significant_digit | 6 |
| units | 1e-6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xch4_uncertainty#
| Field | Value |
|---|---|
| long_name | 1-sigma uncertainty of the retrieved column-average dry-air mole fraction of atmospheric methane |
| units | 1e-9 |
| comment | detector noise-driven 1-sigma uncertainty of the retrieved column-average dry-air mole fraction of atmospheric methane (XCH4) in ppb |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xch4_averaging_kernel#
| Field | Value |
|---|---|
| long_name | normalized column averaging kernel |
| units | 1 |
| comment | The normalized column-averaging kernel represents the sensitivity of the retrieved XCH4 to the atmospheric methane mole fraction depending on pressure (height). All values represent layer averages within the corresponding pressure levels. Values near one are ideal and indicate that the influence of the a priori is minimal. Profiles are ordered from surface to top of atmosphere. |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 36330 |
| shape | 3633, 10 |
| chunk_sizes | 3633, 10 |
| file_chunk_sizes | 3633, 10 |
| data_type | float32 |
| dimensions | sounding_dim, layer_dim |
| file_dimensions | sounding_dim, layer_dim |
ch4_profile_apriori#
| Field | Value |
|---|---|
| long_name | a priori profile of dry-air mole fraction of atmospheric methane (ppb) |
| units | 1e-9 |
| comment | a priori profile of dry-air mole fraction of atmospheric methane (XCH4) in ppp |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 36330 |
| shape | 3633, 10 |
| chunk_sizes | 3633, 10 |
| file_chunk_sizes | 3633, 10 |
| data_type | float32 |
| dimensions | sounding_dim, layer_dim |
| file_dimensions | sounding_dim, layer_dim |
xch4_quality_flag#
| Field | Value |
|---|---|
| comment | 0=good, 1=bad |
| long_name | Retrieval quality flag |
| least_significant_digit | 6 |
| units | 1 |
| orig_data_type | int32 |
| fill_value | 9223372036854775807 |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | int64 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
dry_airmass_layer#
| Field | Value |
|---|---|
| long_name | Dry airmass per layer |
| units | m-2 |
| comments | The dry airmass per layer, units are molecules cm-2 |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 36330 |
| shape | 3633, 10 |
| chunk_sizes | 3633, 10 |
| file_chunk_sizes | 3633, 10 |
| data_type | float32 |
| dimensions | sounding_dim, layer_dim |
| file_dimensions | sounding_dim, layer_dim |
surface_elevation#
| Field | Value |
|---|---|
| standard_name | height |
| long_name | Height |
| units | m |
| comments | Height is the vertical distance above the surface |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
surface_temperature#
| Field | Value |
|---|---|
| least_significant_digit | 6 |
| long_name | Surface temperature |
| units | Kelvin |
| comment | Surface temperature within SCIAMACHY ground-pixel (from ECMWF) |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
chi2_ch4#
| Field | Value |
|---|---|
| long_name | Chi-squared |
| units | 1 |
| comments | Chi_squared value of the sounding (CH4 fit) |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
chi2_co2#
| Field | Value |
|---|---|
| long_name | Chi-squared |
| units | 1 |
| comments | Chi_squared value of the sounding (CH4 fit) |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xco2_macc#
| Field | Value |
|---|---|
| least_significant_digit | 6 |
| long_name | column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from MACC(downloaded August 2016 from portal) |
| units | 1e-6 |
| comment | column-average dry-air mole fraction of atmospheric carbon dioxide (XCO2) in ppm (cans be used to replace the XCO2 rescaling factor if warranted) |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xco2_CT2015#
| Field | Value |
|---|---|
| long_name | column-average dry-air mole fraction of atmospheric carbon dioxide (ppm) from CarbonTracker2015 |
| comment | column-average dry-air mole fraction of atmospheric carbon dioxide (XCO2) in ppm from CT2015 (the one used for XCH4 re-scaling) |
| least_significant_digit | 6 |
| units | 1e-6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
xch4_v71#
| Field | Value |
|---|---|
| long_name | column-average dry-air mole fraction of atmospheric methane (ppm) from the last version IMAP v71 (CT2011 used and older bias correction) |
| units | 1e-9 |
| comment | column-average dry-air mole fraction of atmospheric methane (ppm) from the last version (CT2011 used and older bias correction) |
| least_significant_digit | 6 |
| orig_data_type | float32 |
| fill_value | None |
| size | 3633 |
| shape | 3633 |
| chunk_sizes | 3633 |
| file_chunk_sizes | 3633 |
| data_type | float32 |
| dimensions | sounding_dim |
| file_dimensions | sounding_dim |
Full dataset metadata#
| Field | Value |
|---|---|
| comment | These data were produced at SRON Netherlands Institute for Space Research in the frame of the ESA GHG CCI project |
| product_version | v7-2 |
| references | http://www.esa-ghg-cii.org/; http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50332/abstract; http://onlinelibrary.wiley.com/doi/10.1029/2011GL047888/abstract |
| title | ESA Greenhouse Gases Climate Change Initiative (GHG_cci): Column-averaged CH4 from SCIAMACHY generated with the IMAP-DOAS algorithm (CH4_SCI_IMAP), v7.2 |
| project | Climate Change Initiative - European Space Agency |
| source | SCIAMACHY L1B version v70 |
| history | 15.05.2014 - product generated with IMAP v72 |
| ecv | GHG |
| institute | Netherlands Institute for Space Research |
| processing_level | L2 |
| product_string | IMAP |
| data_type | CH4 |
| sensor_id | SCIAMACHY |
| platform_id | Envisat |
| 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. |
| publication_date | 2018-03-19T21:16:29 |
| uuid | 8f5623a85d2e4b9b8ab5313f65a7c994 |
| catalog_url | https://catalogue.ceda.ac.uk/uuid/8f5623a85d2e4b9b8ab5313f65a7c994 |
| cci_project | GHG |