# ACE_FTS_L2_main

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of `ACE_FTS_L2_main` data.

field name | type | dimensions | unit | description
--- | --- | --- | --- | ---
datetime | double | {time} | [seconds since 2000-01-01] | date and time of occultation 30 km geometric tangent point
datetime_start | double | {time} | [seconds since 2000-01-01] | date and time of start of measurement
datetime_stop | double | {time} | [seconds since 2000-01-01] | date and time of end of measurement
orbit_index | int32 |  |  | absolute orbit number
latitude | double | {vertical} | [degree_north] | latitude of 30 km geometric tangent point for occultation
longitude | double | {vertical} | [degree_east] | longitude of 30 km geometric tangent point for occultation
altitude | double | {vertical} | [km] | tangent altitude grid for retrieved parameters and species
temperature | double | {vertical} | [K] | temperature
pressure | double | {vertical} | [hPa] | pressure
number_density | double | {vertical} | [cm^-3] | atmospheric density
H2O_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for H2O
H2O_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for H2O. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
O3_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for O3
O3_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for O3. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
N2O_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for N2O
N2O_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for N2O. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CO_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CO
CO_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CO. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CH4_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CH4
CH4_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CH4. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
NO_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for NO
NO_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for NO. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
NO2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for NO2
NO2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for NO2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
HNO3_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for HNO3
HNO3_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for HNO3. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
HF_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for HF
HF_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for HF. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
HCl_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for HCl
HCl_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for HCl. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
OCS_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for OCS
OCS_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for OCS. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
N2O5_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for N2O5
N2O5_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for N2O5. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
ClONO2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for ClONO2
ClONO2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for ClONO2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
HCN_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for HCN
HCN_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for HCN. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CH3Cl_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CH3Cl
CH3Cl_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CH3Cl. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CF4_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CF4
CF4_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CF4. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CCl2F2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CCl2F2
CCl2F2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CCl2F2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CCl3F_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CCl3F
CCl3F_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CCl3F. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
COF2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for COF2
COF2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for COF2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
C2H6_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for C2H6
C2H6_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for C2H6. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
C2H2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for C2H2
C2H2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for C2H2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
CHF2Cl_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for CHF2Cl
CHF2Cl_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for CHF2Cl. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
SF6_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for SF6
SF6_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for SF6. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
ClO_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for ClO
ClO_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for ClO. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
HO2NO2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for HO2NO2
HO2NO2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for HO2NO2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
H2O2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for H2O2
H2O2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for H2O2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
HOCl_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for HOCl
HOCl_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for HOCl. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
N2_volume_mixing_ratio | double | {vertical} | [ppmv] | volume mixing ratio for N2
N2_volume_mixing_ratio_uncertainty | double | {vertical} | [ppmv] | volume mixing ratio uncertainty for N2. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value
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 | /date
description | date field from header section converted to seconds since 2000-01-01
datetime_start | path | /start_time
description | start_time field from header section converted to seconds since 2000-01-01
datetime_stop | path | /end_time
description | end_time field from header section converted to seconds since 2000-01-01
orbit_index | description | extracted from the filename (assuming ssXXXXX… or srXXXXX… format); set to 0 if extraction of the value was not possible
latitude | path | /latitude
description | latitude field from header section
longitude | path | /longitude
description | longitude field from header section
altitude | path | /data section/z
temperature | path | /data section/T
pressure | path | /data section/P (atm)
number_density | path | /data section/dens
H2O_volume_mixing_ratio | path | /data section/H2O
H2O_volume_mixing_ratio_uncertainty | path | /data section/H2O_err
O3_volume_mixing_ratio | path | /data section/O3
O3_volume_mixing_ratio_uncertainty | path | /data section/O3_err
N2O_volume_mixing_ratio | path | /data section/N2O
N2O_volume_mixing_ratio_uncertainty | path | /data section/N2O_err
CO_volume_mixing_ratio | path | /data section/CO
CO_volume_mixing_ratio_uncertainty | path | /data section/CO_err
CH4_volume_mixing_ratio | path | /data section/CH4
CH4_volume_mixing_ratio_uncertainty | path | /data section/CH4_err
NO_volume_mixing_ratio | path | /data section/NO
NO_volume_mixing_ratio_uncertainty | path | /data section/NO_err
NO2_volume_mixing_ratio | path | /data section/NO2
NO2_volume_mixing_ratio_uncertainty | path | /data section/NO2_err
HNO3_volume_mixing_ratio | path | /data section/HNO3
HNO3_volume_mixing_ratio_uncertainty | path | /data section/HNO3_err
HF_volume_mixing_ratio | path | /data section/HF
HF_volume_mixing_ratio_uncertainty | path | /data section/HF_err
HCl_volume_mixing_ratio | path | /data section/HCl
HCl_volume_mixing_ratio_uncertainty | path | /data section/HCl_err
OCS_volume_mixing_ratio | path | /data section/OCS
OCS_volume_mixing_ratio_uncertainty | path | /data section/OCS_err
N2O5_volume_mixing_ratio | path | /data section/N2O5
N2O5_volume_mixing_ratio_uncertainty | path | /data section/N2O5_err
ClONO2_volume_mixing_ratio | path | /data section/ClONO2
ClONO2_volume_mixing_ratio_uncertainty | path | /data section/ClONO2_err
HCN_volume_mixing_ratio | path | /data section/HCN
HCN_volume_mixing_ratio_uncertainty | path | /data section/HCN_err
CH3Cl_volume_mixing_ratio | path | /data section/CH3Cl
CH3Cl_volume_mixing_ratio_uncertainty | path | /data section/CH3Cl_err
CF4_volume_mixing_ratio | path | /data section/CF4
CF4_volume_mixing_ratio_uncertainty | path | /data section/CF4_err
CCl2F2_volume_mixing_ratio | path | /data section/CCl2F2
CCl2F2_volume_mixing_ratio_uncertainty | path | /data section/CCl2F2_err
CCl3F_volume_mixing_ratio | path | /data section/CCl3F
CCl3F_volume_mixing_ratio_uncertainty | path | /data section/CCl3F_err
COF2_volume_mixing_ratio | path | /data section/COF2
COF2_volume_mixing_ratio_uncertainty | path | /data section/COF2_err
C2H6_volume_mixing_ratio | path | /data section/C2H6
C2H6_volume_mixing_ratio_uncertainty | path | /data section/C2H6_err
C2H2_volume_mixing_ratio | path | /data section/C2H2
C2H2_volume_mixing_ratio_uncertainty | path | /data section/C2H2_err
CHF2Cl_volume_mixing_ratio | path | /data section/CHF2Cl
CHF2Cl_volume_mixing_ratio_uncertainty | path | /data section/CHF2Cl_err
SF6_volume_mixing_ratio | path | /data section/SF6
SF6_volume_mixing_ratio_uncertainty | path | /data section/SF6_err
ClO_volume_mixing_ratio | path | /data section/ClO
ClO_volume_mixing_ratio_uncertainty | path | /data section/ClO_err
HO2NO2_volume_mixing_ratio | path | /data section/HO2NO2
HO2NO2_volume_mixing_ratio_uncertainty | path | /data section/HO2NO2_err
H2O2_volume_mixing_ratio | path | /data section/H2O2
H2O2_volume_mixing_ratio_uncertainty | path | /data section/H2O2_err
HOCl_volume_mixing_ratio | path | /data section/HOCl
HOCl_volume_mixing_ratio_uncertainty | path | /data section/HOCl_err
N2_volume_mixing_ratio | path | /data section/N2
N2_volume_mixing_ratio_uncertainty | path | /data section/N2_err