BackForward Variable: Cloud optical depth

Full name Cloud optical depth
Definition Effective depth of a cloud from the viewpoint of radiation extinction. OD = exp(-K.Δz) where K is the extinction coefficient [km-1 ], Δz the vertical path [km] between the base and the top of the cloud and the reference wavelength to be specified in the metadata.
Measuring Units dimensionless Uncertainty Units dimless
Horizontal Res Units km Vertical Res Units
Stability Units dimless (Stability /decade)


Comment: The cloud optical depth represents the impact of the cloud water column on radiation propagation. It depends on wavelength.
Last modified: 2019-10-16
Applied in OSCAR/Space Gap Analysis: Yes
  • Domain: Atmosphere
    • Sub-domain: Clouds and precipitations
      • Variable: Cloud optical depth
        • Measured in Layers:
          • TC
  • Cross-cutting themes:

Requirements defined for Cloud optical depth  (2)

This tables shows all related requirements. For more operations/filtering, please consult the full list of Requirements
Note: In reading the values, goal is marked blue, breakthrough green and threshold orange

Id Variable Layer App Area Uncertainty Stability / decade Hor Res Ver Res Obs Cyc Timeliness Coverage Conf Level Val Date Source
3 Cloud optical depth TC CLIC (deprecated) 15 dimless
20 dimless
30 dimless
100 km
200 km
500 km
12 h
16 h
24 h
24 h
30 h
2 d
Global reasonable 1998-10-29 WCRP
793 Cloud optical depth TC Climate Monitoring (GCOS) 50 km 3 h Global reasonable 2019-09-25 GCOS-200: The Global Observing System for Climate: Implementation Needs (Published 2016)