OMI_L2_OMNO2

Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of OMI_L2_OMNO2 data.

field name type dimensions unit description
datetime double {time} [seconds since 2000-01-01] time of the measurement
longitude double {time} [degree_east] longitude of the ground pixel center (WGS84)
latitude double {time} [degree_north] latitude of the ground pixel center (WGS84)
longitude_bounds double {time, 4} [degree_east] longitudes of the ground pixel corners (WGS84)
latitude_bounds double {time, 4} [degree_north] latitudes of the ground pixel corners (WGS84)
solar_zenith_angle double {time} [degree] solar zenith angle at WGS84 ellipsoid for center co-ordinate of the ground pixel
solar_azimuth_angle double {time} [degree] solar azimuth angle at WGS84 ellipsoid for center co-ordinate of the ground pixel, defined East-of-North
viewing_zenith_angle double {time} [degree] viewing zenith angle at WGS84 ellipsoid for center co-ordinate of the ground pixel
viewing_azimuth_angle double {time} [degree] viewing azimuth angle at WGS84 ellipsoid for center co-ordinate of the ground pixel, defined East-of-North
NO2_column_number_density double {time} [molec/cm^2] NO2 vertical column density
NO2_column_number_density_uncertainty double {time} [molec/cm^2] uncertainty of the NO2 vertical column density
tropospheric_NO2_column_number_density double {time} [molec/cm^2] NO2 tropospheric column density
tropospheric_NO2_column_number_density_uncertainty double {time} [molec/cm^2] uncertainty of the NO2 tropospheric column density
tropospheric_NO2_column_number_density_amf double {time} [] air mass factor of the NO2 tropospheric column density
tropospheric_NO2_column_number_density_apriori double {time} [molec/cm^2] apriori of the NO2 tropospheric column density
stratospheric_NO2_column_number_density double {time} [molec/cm^2] NO2 stratospheric column density
stratospheric_NO2_column_number_density_uncertainty double {time} [molec/cm^2] uncertainty of the NO2 stratospheric column density
stratospheric_NO2_column_number_density_amf double {time} [] air mass factor of the NO2 stratospheric column density
stratospheric_NO2_column_number_density_apriori double {time} [molec/cm^2] apriori of the NO2 stratospheric column density
NO2_slant_column_number_density double {time} [molec/cm^2] NO2 slant column density
NO2_slant_column_number_density_uncertainty double {time} [molec/cm^2] uncertainty of the NO2 slant column density
validity int32 {time}   Vertical column density quality flags
tropopause_pressure double {time} [hPa] Pressure of the tropopause
surface_altitude double {time} [m] Terrain height
surface_pressure double {time} [hPa] Terrain pressure
cloud_fraction double {time} [] effective cloud fraction
cloud_fraction_uncertainty double {time} [] uncertainty of the effective cloud fraction
cloud_pressure double {time} [hPa] effective cloud pressure
cloud_pressure_uncertainty double {time} [hPa] uncertainty of the effective cloud 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 OMI_L2_OMNO2 products.

option name legal values description
destriped true ingest slant column densities without destriping correction (default) or with destriping correction (destriped=true)

Mapping description

The shape and size of each ground pixel is not included in the product. HARP therefore provides its own approximation which is based on interpolation of the available center coordinates for each of the ground pixels. Each corner coordinate is determined by its four surrounding center coordinates. The corner coordinate is exactly at the intersection of the cross that can be made with these four points (each line of the cross is the great-circle distance from one center coordinate to the other). In situations where a corner coordinate is not surrounded by four center coordinates (i.e. at the boundaries) virtual center coordinates are created by means of extrapolation. The virtual center coordinate is placed such that the distance to its nearest real center coordinate equals the distance between that nearest real center coordinate and the next center coordinate going further inwards. In mathematical notation: when c(i,m+1) is the virtual center coordinate and c(i,m) and c(i,m-1) are real center coordinates, then ||c(i,m+1) - c(i,m)|| = ||c(i,m) - c(i,m-1)|| and all three coordinates should lie on the same great circle. The four virtual coordinates that lie in the utmost corners of the boundaries are calculated by extrapolating in a diagonal direction (e.g. c(n+1,m+1) is calculated from c(n,m) and c(n-1,m-1)).

The table below details where and how each variable was retrieved from the input product.

field name mapping description
datetime path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/Time[]
description the time of the measurement converted from TAI93 to seconds since 2000-01-01T00:00:00
longitude path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/Longitude[]
latitude path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/Latitude[]
longitude_bounds description interpolated from the available center coordinates for each of the ground pixels
latitude_bounds description interpolated from the available center coordinates for each of the ground pixels
solar_zenith_angle path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/SolarZenithAngle[]
solar_azimuth_angle path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/SolarAzimuthAngle[]
viewing_zenith_angle path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/ViewingZenithAngle[]
viewing_azimuth_angle path /HDFEOS/SWATHS/ColumnAmountNO2/Geolocation_Fields/ViewingAzimuthAngle[]
NO2_column_number_density path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/ColumnAmountNO2[]
NO2_column_number_density_uncertainty path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/ColumnAmountNO2Std[]
tropospheric_NO2_column_number_density path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/ColumnAmountNO2Trop[]
tropospheric_NO2_column_number_density_uncertainty path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/ColumnAmountNO2TropStd[]
tropospheric_NO2_column_number_density_amf available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/AmfTrop[]
tropospheric_NO2_column_number_density_apriori available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/VcdApTrop[]
stratospheric_NO2_column_number_density available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/ColumnAmountNO2Strat[]
stratospheric_NO2_column_number_density_uncertainty available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/ColumnAmountNO2StratStd[]
stratospheric_NO2_column_number_density_amf available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/AmfStrat[]
stratospheric_NO2_column_number_density_apriori available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/VcdApStrat[]
NO2_slant_column_number_density condition destriped unset
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/SlantColumnAmountNO2[]
condition destriped=true
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/SlantColumnAmountNO2Destriped[]
NO2_slant_column_number_density_uncertainty path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/SlantColumnAmountNO2Std[]
validity available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/VcdQualityFlags[]
tropopause_pressure available optional
path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/TropopausePressure[]
surface_altitude path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/TerrainHeight[]
surface_pressure path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/TerrainPressure[]
cloud_fraction path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/CloudFraction[]
cloud_fraction_uncertainty path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/CloudFractionStd[]
cloud_pressure path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/CloudPressure[]
cloud_pressure_uncertainty path /HDFEOS/SWATHS/ColumnAmountNO2/Data_Fields/CloudPressureStd[]