QA4ECV_L2_NO2
Variables
The table below lists the variables that are present in the HARP product that results from an ingestion of QA4ECV_L2_NO2
data.
field name | type | dimensions | unit | description |
---|---|---|---|---|
scan_subindex | int16 | {time} | pixel index (0-based) within the scanline | |
datetime | double | {time} | [seconds since 1995-01-01] | start time of the measurement |
orbit_index | int32 | absolute orbit number | ||
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) |
solar_zenith_angle | float | {time} | [degree] | zenith angle of the Sun at the ground pixel location (WGS84); angle measured away from the vertical |
relative_azimuth_angle | float | {time} | [degree] | relative azimuth angle 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 |
surface_altitude | float | {time} | [m] | surface altitude |
surface_pressure | float | {time} | [hPa] | surface pressure |
pressure_bounds | double | {time, vertical, 2} | [Pa] | pressure boundaries for each layer |
cloud_fraction | float | {time} | [] | cloud fraction |
cloud_fraction_uncertainty | float | {time} | [] | effective cloud fraction uncertainty |
cloud_pressure | float | {time} | [hPa] | cloud optical centroid pressure from the cloud product |
cloud_pressure_uncertainty | float | {time} | [hPa] | cloud optical centroid pressure from the cloud product |
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 |
tropospheric_NO2_column_number_density | float | {time} | [molec/cm^2] | tropospheric vertical column of NO2 |
tropospheric_NO2_column_number_density_uncertainty | float | {time} | [molec/cm^2] | uncertainty of the tropospheric vertical column of NO2 (standard error) |
tropospheric_NO2_column_number_density_avk | float | {time, vertical} | [] | averaging kernel for the tropospheric vertical column number density of NO2 |
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 |
stratospheric_NO2_column_number_density | float | {time} | [molec/cm^2] | stratospheric vertical column of NO2 |
stratospheric_NO2_column_number_density_uncertainty | float | {time} | [molec/cm^2] | uncertainty of the stratospheric vertical column of NO2 (standard error) |
stratospheric_NO2_column_number_density_avk | float | {time, vertical} | [] | averaging kernel for the stratospheric vertical column number density of NO2 |
stratospheric_NO2_column_number_density_amf | float | {time} | [] | stratospheric air mass factor |
NO2_column_number_density | float | {time} | [molec/cm^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} | [molec/cm^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 total column number density of NO2 |
surface_albedo | float | {time} | [] | surface albedo in the NO2 fitting window |
validity | int32 | {time} | processing quality flag | |
index | int32 | {time} | zero-based index of the sample within the source product |
Ingestion options
The table below lists the available ingestion options for QA4ECV_L2_NO2
products.
option name | legal values | description |
---|---|---|
total_column | summed, total | whether to use total_no2_vertical_column (which is derived from the total slant column diveded by the total amf) or summed_no2_total_vertical_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 | path | /PRODUCT/time, /PRODUCT/delta_time[] |
description | time converted from milliseconds since a reference time (with the reference time being 1995-01-01) to seconds since 1995-01-01; the time associated with a scanline is repeated for each pixel in the scanline | |
orbit_index | path | /@orbit |
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[] |
solar_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/solar_zenith_angle[] |
relative_azimuth_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/relative_azimuth_angle[] |
sensor_zenith_angle | path | /PRODUCT/SUPPORT_DATA/GEOLOCATIONS/viewing_zenith_angle[] |
surface_altitude | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_altitude[] |
surface_pressure | path | /PRODUCT/tm5_surface_pressure[] |
pressure_bounds | path | /PRODUCT/tm5_pressure_level_a[], /PRODUCT/tm5_pressure_level_b[], /PRODUCT/tm5_surface_pressure[] |
description | pressure in Pa at level k is derived from surface pressure in hPa as: tm5_pressure_level_a[k] + tm5_pressure_level_b[k] * tm5_surface_pressure[] * 100.0; the TOA pressure is clamped to 1e-3 Pa | |
cloud_fraction | condition | cloud_fraction unset |
path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_fraction[] | |
condition | cloud_fraction=radiance | |
path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/cloud_radiance_fraction_no2[] | |
cloud_fraction_uncertainty | available | optional |
condition | cloud_fraction unset | |
path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_fraction_uncertainty[] | |
cloud_pressure | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_pressure[] |
cloud_pressure_uncertainty | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/cloud_pressure_uncertainty[] |
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_pressure_level_a[], /PRODUCT/tm5_pressure_level_b[], /PRODUCT/tm5_surface_pressure[], /PRODUCT/tm5_tropopause_layer_index[] |
description | pressure in Pa at tropause is derived from the upper bound of the layer with tropopause layer index k: tm5_pressure_level_a[k + 1] + tm5_pressure_level_b[k + 1] * tm5_surface_pressure[] * 100.0 | |
tropospheric_NO2_column_number_density | path | /PRODUCT/tropospheric_no2_vertical_column[] |
tropospheric_NO2_column_number_density_uncertainty | path | /PRODUCT/tropospheric_no2_vertical_column_uncertainty[] |
tropospheric_NO2_column_number_density_avk | path | /PRODUCT/averaging_kernel[], /PRODUCT/amf_total[], /PRODUCT/amf_trop[], /PRODUCT/tm5_tropopause_layer_index[] |
description | averaging_kernel[layer] = if layer <= tm5_tropopause_layer_index then averaging_kernel[layer] * amf_total / amf_trop else 0 | |
tropospheric_NO2_column_number_density_amf | path | /PRODUCT/amf_trop[] |
stratospheric_NO2_column_number_density | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/stratospheric_no2_vertical_column[] |
stratospheric_NO2_column_number_density_uncertainty | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/stratospheric_no2_vertical_column_uncertainty[] |
stratospheric_NO2_column_number_density_avk | path | /PRODUCT/averaging_kernel[], /PRODUCT/amf_total[], /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/amf_strat[], /PRODUCT/tm5_tropopause_layer_index[] |
description | averaging_kernel[layer] = if layer > tm5_tropopause_layer_index then averaging_kernel[layer] * amf_total / amf_strat else 0 | |
stratospheric_NO2_column_number_density_amf | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/amf_strat[] |
NO2_column_number_density | condition | total_column=summed or total_column unset |
path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/summed_no2_total_vertical_column[] | |
condition | total_column=total | |
path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/total_no2_vertical_column[] | |
NO2_column_number_density_uncertainty | condition | total_column=summed or total_column unset |
path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/summed_no2_total_vertical_column_uncertainty[] | |
condition | total_column=total | |
path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/total_no2_vertical_column_uncertainty[] | |
NO2_column_number_density_amf | path | /PRODUCT/amf_total[] |
NO2_column_number_density_avk | path | /PRODUCT/averaging_kernel[] |
surface_albedo | path | /PRODUCT/SUPPORT_DATA/INPUT_DATA/surface_albedo_no2[] |
validity | path | /PRODUCT/SUPPORT_DATA/DETAILED_RESULTS/processing_quality_flags[] |