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GCOS Atmosphere Upper-Air ECV - Water Vapour

Water vapour is the predominant gaseous source of IR opacity in the atmosphere, accounting for about 60% of the natural greenhouse effect for clear skies. It also provides a feedback that reinforces tropospheric warming in model projections of climate change. Water vapour condenses to produce clouds, thereby changing radiative properties and releasing latent heat that drives or modifies atmospheric circulation systems. It plays a role in atmospheric chemistry. The presence of water vapour in the lower stratosphere, even though in small amounts, is radiatively significant. Here, there is potential for additional climate change feedbacks through changes in the processes that control the entry of water vapour through the cold tropical tropopause, changes in the upper stratospheric source due to CH4 oxidation and changes in the transporting Brewer–Dobson circulation.

Product requirements:

  • Total column-water vapour:
    • Frequency: 4hr
    • Resolution: 25km/NA
    • Required Measurement uncertainty: 2%
    • Stability (per decade unless otherwise specified): 0.30%
    • Entity (Satellite): WGClimate
  • Tropospheric profiles of water vapour:
    • Frequency: 4hr (troposphere)
    • Resolution: 25km/2km
    • Required Measurement uncertainty: 5%
    • Stability (per decade unless otherwise specified): 0.30%
    • Entity (Satellite): WGClimate
  • Lower-stratospheric profiles of water vapour:
    • Frequency: daily (stratosphere)
    • Resolution: 100-200km/2km
    • Required Measurement uncertainty: 5%
    • Stability (per decade unless otherwise specified): 0.30%
    • Entity (Satellite): WGClimate
  • Upper tropospheric humidity:
    • Frequency: 1hr
    • Resolution: 25km/NA
    • Required Measurement uncertainty: 5%
    • Stability (per decade unless otherwise specified): 0.30%
    • Entity (Satellite): WGClimate

Contributing networks:

Data sources: