Additional cloud measurement variables (Doppler velocities)

swr99ejo commented 1 year ago

New variables

Doppler velocity

OBSERVATION MATRIX: [ cloud phase] [aerosol phase]
OBJECT OF INTEREST: [hydrometeor] - includes both aerosol and cloud (and insects)
OBSERVED PROPERTY: [velocity]
Description: The radial component of the mean velocity vector of scattering objects in a volume as observed by a remote sensor.

Doppler spectral width

OBSERVATION MATRIX: [ cloud phase] [aerosol phase]
OBJECT OF INTEREST: [hydrometeor] - includes both aerosol and cloud (and insects)
OBSERVED PROPERTY: [velocity]
Description: The radial component of the velocity spectrum width (i.e., the square root of the second spectral moment about the mean velocity) of scattering objects in a volume as observed by a remote sensor.

Doppler spectral skewness

OBSERVATION MATRIX: [ cloud phase] [aerosol phase]
OBJECT OF INTEREST: [hydrometeor] - includes both aerosol and cloud (and insects)
OBSERVED PROPERTY: [velocity]
Description: The radial component of the velocity spectrum skewness (i.e., the third spectral moment about the mean velocity) of scattering objects in a volume as observed by a remote sensor.

Doppler spectral kurtosis

OBSERVATION MATRIX: [ cloud phase] [aerosol phase]
OBJECT OF INTEREST: [hydrometeor] - includes both aerosol and cloud (and insects)
OBSERVED PROPERTY: [velocity]
Description: The radial component of the velocity spectrum kurtosis (i.e., the fourth spectral moment about the mean velocity) of scattering objects in a volume as observed by a remote sensor.

markusfiebig commented 11 months ago

This would imply a redefinition of hydrometeor , which currently is defined as

Any water containing particle in liquid or ice phase

and completely resides in the cloud phase. Is that intended? Can radars really use aerosol particles to infer Doppler velocity?

swr99ejo commented 9 months ago

The hydrometeor definition covers both cloud and precipitation phases. The velocity variables are for both cloud radar and Doppler lidars, so should not be too prescriptive in terms of object of interest. In principle, cloud radars can detect some large aerosol particles (e.g. volcanic ash)

swr99ejo commented 9 months ago

I'm not sure that we have to combine aerosol and water into one object of interest, but the description of these variables should allow for a broader application - we may have instruments in the future for which molecules are the object of interest

markusfiebig commented 7 months ago

aerosol particle radial velocity, matrix: particle phase hydrometeor radial velocity, matrix: cloud phase molecular velocity, matrix: gas phase

The different moments of the velocity will be defined as statistical properties, which are on the agenda.

accepted by @swr99ejo and @markusfiebig

markusfiebig commented 6 months ago

@swr99ejo : Why didn't we include radial in molecular velocity?

markusfiebig commented 5 months ago

molecular velocity, matrix: gas phase is changed to molecular radial velocity, matrix: gas phase

Can be implemented.

markusfiebig commented 3 months ago

Implemented in dev vocabulary.

ACTRIS-Data-Centre / actris-vocabulary

Additional cloud measurement variables (Doppler velocities) #13