# ESACCI_OZONE_L3_NP

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `ESACCI_OZONE_L3_NP` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
datetime_start | double | {time} | [seconds since 2000-01-01] | time coverage start
datetime_stop | double | {time} | [seconds since 2000-01-01] | time coverage end
longitude | float | {longitude} | [degree_east] | longitude of the grid cell center
latitude | float | {latitude} | [degree_north] | latitude of the grid cell center
pressure | float | {latitude, longitude, vertical} | [hPa] | air pressure profile
pressure_bounds | float | {latitude, longitude, vertical, 2} | [hPa] | air pressure boundaries for each profile level
O3_number_density | float | {latitude, longitude, vertical} | [molec/cm^3] | O3 number density
O3_number_density_uncertainty | float | {latitude, longitude, vertical} | [molec/cm^3] | uncertainty of the O3 number density
O3_volume_mixing_ratio | float | {latitude, longitude, vertical} | [ppmv] | O3 volume mixing ratio
O3_volume_mixing_ratio_uncertainty | float | {latitude, longitude, vertical} | [ppmv] | uncertainty of the O3 volume mixing ratio
index | int32 | {time} |  | zero-based index of the sample within the source product

## Mapping description

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

field name | mapping description
--- | ---
datetime_start | path | /@time_coverage_start
description | datetime converted from a start date to seconds since 2000-01-01
datetime_stop | path | /@time_coverage_end
description | datetime converted from an end date to seconds since 2000-01-01
longitude | path | /lon[]
latitude | path | /lat[]
pressure | path | /surface_pressure[], /air_pressure[]
description | repeat location independent air pressure profile (/air_pressure[]) for each grid point and replace value at the lowest level by location dependent surface pressure (/surface_pressure[])
pressure_bounds | path | /surface_pressure[], /air_pressure[]
description | repeat location independent air pressure profile (/air_pressure[]) for each grid point and replace value at the lowest level by location dependent surface pressure (/surface_pressure[]); upper and lower pressure for each profile is based on log-linear interpolation of profile (i.e. upper bound is sqrt(pressure[i+1] * pressure[i]), and lower bound is sqrt(pressure[i] * pressure[i-1])); the lower bound of level 0 is set to pressure[0] and the upper bound for level n-1 is set to pressure[n-1]
O3_number_density | path | /O3_ndens[]
O3_number_density_uncertainty | path | /O3e_ndens[]
O3_volume_mixing_ratio | path | /O3_vmr[]
O3_volume_mixing_ratio_uncertainty | path | /O3e_vmr[]