# ACE_FTS_L2_iso

## Variables

The table below lists the variables that are present in the HARP product that results from an ingestion of ACE_FTS_L2_iso 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_181_volume_mixing_ratio

double

{vertical}

[ppmv]

volume mixing ratio for H2O_181

H2O_181_volume_mixing_ratio_uncertainty

double

{vertical}

[ppmv]

volume mixing ratio uncertainty for H2O_181. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value

H2O_171_volume_mixing_ratio

double

{vertical}

[ppmv]

volume mixing ratio for H2O_171

H2O_171_volume_mixing_ratio_uncertainty

double

{vertical}

[ppmv]

volume mixing ratio uncertainty for H2O_171. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value

H2O_162_volume_mixing_ratio

double

{vertical}

[ppmv]

volume mixing ratio for H2O_162

H2O_162_volume_mixing_ratio_uncertainty

double

{vertical}

[ppmv]

volume mixing ratio uncertainty for H2O_162. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value

CH4_311_volume_mixing_ratio

double

{vertical}

[ppmv]

volume mixing ratio for CH4_311

CH4_311_volume_mixing_ratio_uncertainty

double

{vertical}

[ppmv]

volume mixing ratio uncertainty for CH4_311. If this value is -888 the vmr was not retrieved but obtained by scaling the a priori value

CH4_212_volume_mixing_ratio

double

{vertical}

[ppmv]

volume mixing ratio for CH4_212

CH4_212_volume_mixing_ratio_uncertainty

double

{vertical}

[ppmv]

volume mixing ratio uncertainty for CH4_212. 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

longitude

path

/longitude

description

altitude

path

/data section/z

temperature

path

/data section/T

pressure

path

/data section/P (atm)

number_density

path

/data section/dens

H2O_181_volume_mixing_ratio

path

/data section/H2O_181

H2O_181_volume_mixing_ratio_uncertainty

path

/data section/H2O_181_err

H2O_171_volume_mixing_ratio

path

/data section/H2O_171

H2O_171_volume_mixing_ratio_uncertainty

path

/data section/H2O_171_err

H2O_162_volume_mixing_ratio

path

/data section/H2O_162

H2O_162_volume_mixing_ratio_uncertainty

path

/data section/H2O_162_err

CH4_311_volume_mixing_ratio

path

/data section/CH4_311

CH4_311_volume_mixing_ratio_uncertainty

path

/data section/CH4_311_err

CH4_212_volume_mixing_ratio

path

/data section/CH4_212

CH4_212_volume_mixing_ratio_uncertainty

path

/data section/CH4_212_err