Cloud/Climate Sensitivity Experiments

  1. James E. Hansen and
  2. Taro Takahashi
  1. John O. Roads,
  2. Geoffrey K. Vallis and
  3. Lorraine Remer

Published Online: 19 MAR 2013

DOI: 10.1029/GM029p0092

Climate Processes and Climate Sensitivity

Climate Processes and Climate Sensitivity

How to Cite

Roads, J. O., Vallis, G. K. and Remer, L. (1984) Cloud/Climate Sensitivity Experiments, in Climate Processes and Climate Sensitivity (eds J. E. Hansen and T. Takahashi), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM029p0092

Author Information

  1. Climate Research Group, Scripps Institution of Oceanography University of California, San Diego, A-024, La Jolla, California 92093

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 1984

ISBN Information

Print ISBN: 9780875904047

Online ISBN: 9781118666036



  • Climatology—Congresses;
  • Geophysics—Congresses;
  • Ocean-atmosphere interaction—Congresses


study of the relationships between large-scale cloud fields and large-scale circulation patterns is presented. The basic tool is a multi-level numerical model comprising conservation equations for temperature, water vapor and cloud water and appropriate parameterizations for evaporation, condensation, precipitation and radiative feedbacks. Incorporating an equation for cloud water in a large-scale model, which is somewhat novel, allows the formation and advection of clouds to be treated explicitly. The model is run on a two-dimensional, vertical-horizontal grid with constant winds. It is shown that cloud cover increases with decreased eddy vertical velocity, decreased horizontal advection, decreased atmospheric temperature, increased surface temperature, and decreased precipitation efficiency. The cloud field is found to be well correlated with the relative humidity field except at the highest levels. When radiative feedbacks are incorporated and the temperature increased by increasing CO2 content, cloud amounts decrease at upper-levels or equivalently cloud top height falls. This reduces the temperature response, especially at upper levels, compared with an experiment in which cloud cover is fixed.