S5P_L2_NO2
Variables
The table below lists the variables that are present in the HARP product that results from an ingestion of S5P_L2_NO2 data.
| field name | type | dimensions | unit | description |
|---|---|---|---|---|
| scan_subindex | int16 | {time} | pixel index (0-based) within the scanline | |
| datetime_start | double | {time} | [seconds since 2010-01-01] | start time of the measurement |
| datetime_length | double | [s] | duration of the measurement | |
| orbit_index | int32 | absolute orbit number | ||
| validity | int32 | {time} | processing quality flag | |
| latitude | float | {time} | [degree_north] | latitude of the ground pixel center (WGS84) |
| longitude | float | {time} | [degree_east] | longitude of the ground pixel center (WGS84) |
| latitude_bounds | float | {time, 4} | [degree_north] | latitudes of the ground pixel corners (WGS84) |
| longitude_bounds | float | {time, 4} | [degree_east] | longitudes of the ground pixel corners (WGS84) |
| sensor_latitude | float | {time} | [degree_north] | latitude of the geodetic sub-satellite point (WGS84) |
| sensor_longitude | float | {time} | [degree_east] | longitude of the goedetic sub-satellite point (WGS84) |
| sensor_altitude | float | {time} | [m] | altitude of the satellite with respect to the geodetic sub-satellite point (WGS84) |
| solar_zenith_angle | float | {time} | [degree] | zenith angle of the Sun at the ground pixel location (WGS84); angle measured away from the vertical |
| solar_azimuth_angle | float | {time} | [degree] | azimuth angle of the Sun at the ground pixel location (WGS84); angle measured East-of-North |
| sensor_zenith_angle | float | {time} | [degree] | zenith angle of the satellite at the ground pixel location (WGS84); angle measured away from the vertical |
| sensor_azimuth_angle | float | {time} | [degree] | azimuth angle of the satellite at the ground pixel location (WGS84); angle measured East-of-North |
| pressure_bounds | double | {time, vertical, 2} | [Pa] | pressure boundaries |
| tropospheric_NO2_column_number_density | float | {time} | [mol/m^2] | tropospheric vertical column of NO2 |
| tropospheric_NO2_column_number_density_uncertainty | float | {time} | [mol/m^2] | uncertainty of the tropospheric vertical column of NO2 (standard error) |
| tropospheric_NO2_column_number_density_validity | int8 | {time} | continuous quality descriptor, varying between 0 (no data) and 1 (full quality data) | |
| tropospheric_NO2_column_number_density_amf | float | {time} | [] | tropospheric air mass factor, computed by integrating the altitude dependent air mass factor over the atmospheric layers from the surface up to and including the layer with the tropopause |
| tropospheric_NO2_column_number_density_avk | float | {time, vertical} | [] | averaging kernel for the tropospheric vertical column number density of NO2 |
| NO2_column_number_density | float | {time} | [mol/m^2] | total vertical column of NO2 (ratio of the slant column density of NO2 and the total air mass factor) |
| NO2_column_number_density_uncertainty | float | {time} | [mol/m^2] | uncertainty of the total vertical column of NO2 (standard error) |
| NO2_column_number_density_amf | float | {time} | [] | total air mass factor, computed by integrating the altitude dependent air mass factor over the atmospheric layers from the surface to top-of-atmosphere |
| NO2_column_number_density_avk | float | {time, vertical} | [] | averaging kernel for the air mass factor correction, describing the NO2 profile sensitivity of the vertical column density |
| stratospheric_NO2_column_number_density | float | {time} | [mol/m^2] | stratospheric vertical column of NO2 |
| stratospheric_NO2_column_number_density_uncertainty | float | {time} | [mol/m^2] | uncertainty of the stratospheric vertical column of NO2 (standard error) |
| stratospheric_NO2_column_number_density_amf | float | {time} | [] | stratospheric air mass factor |
| stratospheric_NO2_column_number_density_avk | float | {time, vertical} | [] | averaging kernel for the stratospheric vertical column number density of NO2 |
| NO2_slant_column_number_density | float | {time} | [mol/m^2] | slant column of NO2 |
| NO2_slant_column_number_density_uncertainty | float | {time} | [mol/m^2] | uncertainty of the slant column of NO2 |
| cloud_fraction | float | {time} | [] | cloud fraction for NO2 fitting window |
| absorbing_aerosol_index | float | {time} | [] | aerosol index |
| cloud_albedo | float | {time} | [] | cloud albedo |
| cloud_pressure | float | {time} | [Pa] | cloud pressure |
| surface_albedo | float | {time} | [] | surface albedo |
| surface_altitude | float | {time} | [m] | surface altitude |
| surface_altitude_uncertainty | float | {time} | [m] | surface altitude precision |
| surface_pressure | float | {time} | [Pa] | surface pressure |
| snow_ice_type | int8 | {time} | surface snow/ice type; enumeration values: snow_free_land (0), sea_ice (1), permanent_ice (2), snow (3), ocean (4) | |
| sea_ice_fraction | float | {time} | [] | sea-ice concentration (as a fraction) |
| tropopause_pressure | double | {time} | [Pa] | tropopause pressure |
| index | int32 | {time} | zero-based index of the sample within the source product |
Ingestion options
The table below lists the available ingestion options for S5P_L2_NO2 products.
| option name | legal values | description |
|---|---|---|
| total_column | summed, total | whether to use nitrogendioxide_total_column (which is derived from the total slant column diveded by the total amf) or nitrogendioxide_summed_total_column (which is the sum of the retrieved tropospheric and statospheric columns); option values are ‘summed’ (default) and ‘total’ |
| cloud_fraction | radiance | whether to ingest the cloud fraction (default) or the radiance cloud fraction (cloud_fraction=radiance) |
Mapping description
The table below details where and how each variable was retrieved from the input product.
| field name | mapping description | |
|---|---|---|
| scan_subindex | description | the scanline and pixel dimensions are collapsed into a temporal dimension; the index of the pixel within the scanline is computed as the index on the temporal dimension modulo the number of scanlines |
| datetime_start | path | /PRODUCT/time, /PRODUCT/delta_time[] |
| description | time converted from milliseconds since a reference time (given as seconds since 2010-01-01) to seconds since 2010-01-01 (using 86400 seconds per day); the time associated with a scanline is repeated for each pixel in the scanline | |
| datetime_length | path | /@time_coverage_resolution |
| description | the measurement length is parsed assuming the ISO 8601 ‘PT%(interval_seconds)fS’ format | |
| orbit_index | path | /@orbit |
| validity | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/processing_quality_flags[] |
| description | the uint32 data is cast to int32 | |
| latitude | path | /PRODUCT/latitude[] |
| longitude | path | /PRODUCT/longitude[] |
| latitude_bounds | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/latitude_bounds[] |
| longitude_bounds | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/longitude_bounds[] |
| sensor_latitude | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/satellite_latitude[] |
| description | the satellite latitude associated with a scanline is repeated for each pixel in the scanline | |
| sensor_longitude | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/satellite_longitude[] |
| description | the satellite longitude associated with a scanline is repeated for each pixel in the scanline | |
| sensor_altitude | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/satellite_altitude[] |
| description | the satellite altitude associated with a scanline is repeated for each pixel in the scanline | |
| solar_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_zenith_angle[] |
| solar_azimuth_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_azimuth_angle[] |
| sensor_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_zenith_angle[] |
| sensor_azimuth_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_azimuth_angle[] |
| pressure_bounds | path | /PRODUCT/tm5_constant_a[], /PRODUCT/tm5_constant_b[], /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_pressure[] |
| description | pressure in Pa at level k is derived from surface pressure in Pa as: tm5_constant_a[k] + tm5_constant_b[k] * surface_pressure[]; the top of atmosphere pressure is clamped to 1e-3 Pa | |
| tropospheric_NO2_column_number_density | path | /PRODUCT/nitrogendioxide_tropospheric_column[] |
| tropospheric_NO2_column_number_density_uncertainty | path | /PRODUCT/nitrogendioxide_tropospheric_column_precision[] |
| tropospheric_NO2_column_number_density_validity | path | /PRODUCT/qa_value |
| tropospheric_NO2_column_number_density_amf | path | /PRODUCT/air_mass_factor_troposphere[] |
| tropospheric_NO2_column_number_density_avk | path | /PRODUCT/averaging_kernel[], /PRODUCT/air_mass_factor_total[], /PRODUCT/air_mass_factor_troposphere[], /PRODUCT/tm5_tropopause_layer_index[] |
| description | averaging_kernel[layer] = if layer <= tm5_tropopause_layer_index then averaging_kernel[layer] * air_mass_factor_total / air_mass_factor_troposphere else 0 | |
| NO2_column_number_density | condition | total_column=summed or total_column unset |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/nitrogendioxide_summed_total_column[] | |
| condition | total_column=total | |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/nitrogendioxide_total_column[] | |
| NO2_column_number_density_uncertainty | condition | total_column=summed or total_column unset |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/nitrogendioxide_summed_total_column_precision[] | |
| condition | total_column=total | |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/nitrogendioxide_total_column_precision[] | |
| NO2_column_number_density_amf | path | /PRODUCT/air_mass_factor_total[] |
| NO2_column_number_density_avk | path | /PRODUCT/averaging_kernel[] |
| stratospheric_NO2_column_number_density | path | /PRODUCT/nitrogendioxide_tropospheric_column[] |
| stratospheric_NO2_column_number_density_uncertainty | path | /PRODUCT/nitrogendioxide_tropospheric_column_precision[] |
| stratospheric_NO2_column_number_density_amf | path | /PRODUCT/air_mass_factor_troposphere[] |
| stratospheric_NO2_column_number_density_avk | path | /PRODUCT/averaging_kernel[], /PRODUCT/air_mass_factor_total[], /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/air_mass_factor_stratosphere[], /PRODUCT/tm5_tropopause_layer_index[] |
| description | averaging_kernel[layer] = if layer > tm5_tropopause_layer_index then averaging_kernel[layer] * air_mass_factor_total / air_mass_factor_stratosphere else 0 | |
| NO2_slant_column_number_density | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/nitrogendioxide_slant_column_density[] |
| NO2_slant_column_number_density_uncertainty | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/nitrogendioxide_slant_column_density_precision[] |
| cloud_fraction | condition | cloud_fraction unset |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/cloud_fraction_crb_nitrogendioxide_window[] | |
| condition | cloud_fraction=radiance | |
| path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/cloud_radiance_fraction_nitrogendioxide_window[] | |
| absorbing_aerosol_index | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/aerosol_index_354_388 |
| cloud_albedo | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_albedo_crb |
| cloud_pressure | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_pressure_crb |
| surface_albedo | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_albedo_nitrogendioxide_window |
| surface_altitude | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_altitude[] |
| surface_altitude_uncertainty | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_altitude_precision[] |
| surface_pressure | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_pressure[] |
| snow_ice_type | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/snow_ice_flag[] |
| description | 0: snow_free_land (0), 1-100: sea_ice (1), 101: permanent_ice (2), 103: snow (3), 255: ocean (4), other values map to -1 | |
| sea_ice_fraction | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/snow_ice_flag[] |
| description | if 1 <= snow_ice_flag <= 100 then snow_ice_flag/100.0 else 0.0 | |
| tropopause_pressure | path | /PRODUCT/tm5_constant_a[], /PRODUCT/tm5_constant_b[], /PRODUCT/tm5_tropopause_layer_index[], /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_pressure[] |
| description | pressure in Pa at tropause is derived from the upper bound of the layer with tropopause layer index k: tm5_constant_a[k + 1] + tm5_constant_b[k + 1] * surface_pressure[] | |