The features of cloud overlapping in Eastern Asia and their effect on cloud radiative forcing


Characteristics of cloud overlap over Eastern Asia are analyzed using a three-year dataset (2007–2009) from the cloud observing satellite CloudSat. Decorrelation depth L* cf is retrieved, which represents cloud overlap characteristics in the simulation of cloud-radiation processes in global climate models. Results show that values of L* cf in six study regions are generally within the range 0–3 km. By categorizing L* cf according to cloud amount in subregions, peak L* cf appears near subregions with cloud amount between 0.6 and 0.8. Average L* cf is 2.5 km. L* cf at higher altitudes is generally larger than at lower latitudes. Seasonal variations of L* cf are also clearly demonstrated. The sensitivity of cloud radiative forcing (CRF) to L* cf in Community Atmosphere Model 3.0 of the National Center for Atmospheric Research (CAM3/NCAR) is analyzed. The result shows that L* cf can have a big impact on simulation of CRF, especially in major monsoon regions and the Mid-Eastern Pacific, where the difference in CRF can reach 40–50 W m−2. Therefore, accurate parameterization of cloud vertical overlap structure is important to CRF simulation and its feedback to climate.

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Zhang, H., Peng, J., Jing, X. et al. The features of cloud overlapping in Eastern Asia and their effect on cloud radiative forcing. Sci. China Earth Sci. 56, 737–747 (2013).

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  • cloud overlap hypothesis
  • decorrelation depth
  • CloudSat
  • stochastic cloud generator (SCG)
  • cloud radiation