# GOMOS_L2

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `GOMOS_L2` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
datetime | double | {time} | [seconds since 2000-01-01] | time of the profile
datetime_start | double | {time} | [seconds since 2000-01-01] | start time of the profile
datetime_stop | double | {time} | [seconds since 2000-01-01] | stop time of the profile
orbit_index | int32 |  |  | absolute orbit number
altitude | double | {time, vertical} | [m] | altitude
latitude | double | {time, vertical} | [degree_north] | latitude
longitude | double | {time, vertical} | [degree_east] | longitude
O3_number_density | double | {time, vertical} | [molec/cm3] | Ozone local density
O3_number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the ozone local density
O3_number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the ozone local density
NO2_number_density | double | {time, vertical} | [molec/cm3] | NO2 local density
NO2_number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the NO2 local density
NO2_number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the NO2 local density
NO3_number_density | double | {time, vertical} | [molec/cm3] | NO3 local density
NO3_number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the NO3 local density
NO3_number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the NO3 local density
O2_number_density | double | {time, vertical} | [molec/cm3] | O2 local density
O2_number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the O2 local density
O2_number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the O2 local density
H2O_number_density | double | {time, vertical} | [molec/cm3] | H2O local density
H2O_number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the H2O local density
H2O_number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the H2O local density
OClO_number_density | double | {time, vertical} | [molec/cm3] | OClO local density
OClO_number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the OClO local density
OClO_number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the OClO local density
aerosol_extinction_coefficient | double | {time, vertical} | [1/km] | aerosol extinction coefficient
aerosol_extinction_coefficient_uncertainty | double | {time, vertical} | [1/km] | standard deviation for the aerosol extinction coefficient
pressure | double | {time, vertical} | [Pa] | atmospheric pressure from external model
temperature | double | {time, vertical} | [K] | temperature
temperature_uncertainty | double | {time, vertical} | [K] | standard deviation for the local temperature
number_density | double | {time, vertical} | [molec/cm3] | air density
number_density_uncertainty | double | {time, vertical} | [molec/cm3] | standard deviation for the local air density
number_density_validity | int16 | {time, vertical} |  | PCD (product confidence data) value for the local air density
sensor_altitude | double | {time, vertical} | [m] | altitude of the satellite
sensor_latitude | double | {time, vertical} | [degree_north] | latitude of the satellite position
sensor_longitude | double | {time, vertical} | [degree_east] | longitude of the satellite position
scene_type | int8 | {time} |  | illumination condition for the profile; enumeration values: dark (0), bright (1), twilight (2), straylight (3), twilight_straylight (4)
index | int32 | {time} |  | zero-based index of the sample within the source product

## Ingestion options

The table below lists the available ingestion options for `GOMOS_L2` products.

option name | legal values | description
--- | --- | ---
temperature | model | retrieve the locally measured temperature (default) or the temperature from the external model (temperature=model)
air | model | retrieve the locally measured air density (default) or the air density from the external model (air=model)

## Mapping description

GOMOS Level 2 products only contain a single profile; all measured profile points will be provided in reverse order (from low altitude to high altitude) in the profile

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

field name | mapping description
--- | ---
datetime | path | /nl_geolocation[]/dsr_time
description | time of mid record
datetime_start | path | /nl_geolocation[]/dsr_time
description | time of first record
datetime_stop | path | /nl_geolocation[]/dsr_time
description | time of last record
orbit_index | path | /mph/abs_orbit
altitude | path | /nl_geolocation[]/tangent_alt
latitude | path | /nl_geolocation[]/tangent_lat
longitude | path | /nl_geolocation[]/tangent_long
O3_number_density | path | /nl_local_species_density[]/o3
O3_number_density_uncertainty | condition | CODA product version < 2
path | /nl_local_species_density[]/o3_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | CODA product version >= 2
path | /nl_local_species_density[]/o3_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
O3_number_density_validity | path | /nl_local_species_density[]/pcd[0]
NO2_number_density | path | /nl_local_species_density[]/no2
NO2_number_density_uncertainty | condition | CODA product version < 2
path | /nl_local_species_density[]/no2_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | CODA product version >= 2
path | /nl_local_species_density[]/no2_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
NO2_number_density_validity | path | /nl_local_species_density[]/pcd[1]
NO3_number_density | path | /nl_local_species_density[]/no3
NO3_number_density_uncertainty | condition | CODA product version < 2
path | /nl_local_species_density[]/no3_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | CODA product version >= 2
path | /nl_local_species_density[]/no3_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
NO3_number_density_validity | path | /nl_local_species_density[]/pcd[2]
O2_number_density | path | /nl_local_species_density[]/o2
O2_number_density_uncertainty | condition | CODA product version < 2
path | /nl_local_species_density[]/o2_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | CODA product version >= 2
path | /nl_local_species_density[]/o2_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
O2_number_density_validity | path | /nl_local_species_density[]/pcd[4]
H2O_number_density | path | /nl_local_species_density[]/h2o
H2O_number_density_uncertainty | condition | CODA product version < 2
path | /nl_local_species_density[]/h2o_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | CODA product version >= 2
path | /nl_local_species_density[]/h2o_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
H2O_number_density_validity | path | /nl_local_species_density[]/pcd[5]
OClO_number_density | path | /nl_local_species_density[]/oclo
OClO_number_density_uncertainty | condition | CODA product version < 2
path | /nl_local_species_density[]/oclo_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | CODA product version >= 2
path | /nl_local_species_density[]/oclo_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
OClO_number_density_validity | path | /nl_local_species_density[]/pcd[6]
aerosol_extinction_coefficient | path | /nl_aerosols[]/local_ext
aerosol_extinction_coefficient_uncertainty | path | /nl_aerosols[]/local_ext_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
pressure | path | /nl_geolocation[]/tangent_atm_p
temperature | condition | temperature unset
path | /nl_geolocation[]/local_temp
condition | temperature=model
path | /nl_geolocation[]/tangent_temp
temperature_uncertainty | available | optional
condition | temperature unset
path | /nl_geolocation[]/local_temp_std
number_density | available | optional
condition | air unset
path | /nl_local_species_density[]/air
condition | air=model and CODA product version > 0
path | /nl_geolocation[]/tangent_density
number_density_uncertainty | available | optional
condition | air unset and CODA product version < 2
path | /nl_local_species_density[]/air_std
description | values equal to 6553.5% will be set to NaN; value will be converted to an uncertainty by multiplying with the absolute value of the measured concentration
condition | air unset and CODA product version >= 2
path | /nl_local_species_density[]/air_std
description | values equal to 6554 will be set to NaN; value will be converted to an uncertainty by using the log10(v)/0.005 conversion
number_density_validity | available | optional
condition | air unset
path | /nl_local_species_density[]/pcd[3]
sensor_altitude | path | /nl_geolocation[]/tangent_alt
sensor_latitude | path | /nl_geolocation[]/lat
sensor_longitude | path | /nl_geolocation[]/longit
scene_type | condition | CODA product version 0
path | /nl_summary_quality[0]/limb_flag
condition | CODA product version 1 and higher
path | /nl_summary_quality[0]/obs_illum_cond