# ESACCI_OZONE_L4_NP

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `ESACCI_OZONE_L4_NP` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
datetime | double | {time} | [seconds since 2000-01-01] | time of the measurement
longitude | float | {longitude} | [degree_east] | longitude of the grid cell center
latitude | float | {latitude} | [degree_north] | latitude of the grid cell center
geopotential_height | float | {time, latitude, longitude, vertical} | [m] | geopotential height
temperature | float | {time, latitude, longitude, vertical} | [K] | temperature
pressure | float | {time, latitude, longitude, vertical} | [Pa] | air pressure profile
pressure_bounds | float | {time, latitude, longitude, vertical, 2} | [Pa] | air pressure boundaries for each profile layer
O3_column_number_density | float | {time, latitude, longitude, vertical} | [molec/m^2] | O3 column number density
O3_column_number_density_uncertainty | float | {time, latitude, longitude, vertical} | [molec/m^2] | uncertainty of the O3 column number density
O3_volume_mixing_ratio | float | {time, latitude, longitude, vertical} | [] | O3 volume mixing ratio
O3_volume_mixing_ratio_uncertainty | float | {time, latitude, longitude, vertical} | [] | 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 | path | /@time_coverage_start, /time[]
description | datetime converted from time in hours (time[]) since the start of the product (@time_coverage_start) to seconds since 2000-01-01
longitude | path | /lon[]
latitude | path | /lat[]
geopotential_height | path | /Gph[]
temperature | path | /Temperature[]
pressure | path | /Psurf[], /Hybride_coef_fa[], /Hybride_coef_fb[]
description | pressure at the center of layer k is derived from surface air pressure as: Hybride_coef_fa[k] + Hybride_coef_fb[k] * Psurf[]
pressure_bounds | path | /Psurf[], /Hybride_coef_a[], /Hybride_coef_b[]
description | pressure at level m is derived from surface air pressure as: Hybride_coef_a[m] + Hybride_coef_b[m] * Psurf[]
O3_column_number_density | path | /O3_dens[]
O3_column_number_density_uncertainty | path | /O3s_dens[]
O3_volume_mixing_ratio | path | /O3_vmr[]
O3_volume_mixing_ratio_uncertainty | path | /O3s_vmr[]