Abstract
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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Ramanathan V, Cess R D, Harrison E F, et al. Cloud-radiative forcing and climate: Results from the earth radiation budget experiment. Science, 1989, 243:57–63
Wang H Q, Zhao G X. Cloud and radiation. Sci Atmos Sin, 1994, 18 (Suppl):910–932
Ding S G, Zhao C S, Shi G Y, et al. Analysis of global total cloud amount variation over the past 20 years. J Appl Meteorol, 2005, 16:670–676
Sun B, Groisman P Y. Cloudiness variations over the former Soviet Union. Int J Climatol, 2000, 20:1097–1111
Houghton J T, Ding Y, Griggs D J, et al. Climate Change: The Scientific Basis. New York: Cambridge University Press, 2001. 1–421
Wetherald R T, Manabe S. Cloud feedback processes in a general circulation model. J Atmos Sci, 1988, 45:1397–1415
Houghton J T, Ding Y, Griggs D J, et al. Climate Change: The Scientific Basis. Cambridge: Cambridge University Press, 2001. 148–149
Zhang H, Jing X W. Effect of cloud overlap assumptions in climate models on modeled earth-atmosphere radiative fields (in Chinese). Chin J Atmos Sci, 2010, 34:520–532
Jing X W, Zhang H, Guo P W. A study of the effect of sub-grid cloud structure on global radiation in climate models (in Chinese). Acta Meteorol Sin, 2010, 67:1058–1068
Manabe S, Strickler R F. Thermal equilibrium of the atmosphere with a convective adjustment. J Atmos Sci, 1964, 21:361–385
Geleyn J F, Hollingsworth A. An economical analytical method for the computation of the interaction between scattering and line absorption of radiation. Cont Atmos Phys, 1979, 52:1–16
Morcrette J J, Fouquart Y. The overlapping of cloud layers in shortwave radiation parameterizations. J Atmos Sci, 1986, 43:321–328
Barker H W, Stephens G L, Partain P T, et al. Assessing 1D atmospheric solar radiative transfer models: Interpretation and handling of unresolved clouds. J Clim, 2003, 16:2676–2699
Morcrette J J, Jakob C. The response of the ECMWF model to changes in cloud overlap assumption. Mon Weather Rev, 2000, 128:1707–1732
Tian L, Curry J A. Cloud overlap statistics. J Geophys Res, 1989, 94:9925–9935
Barker H W, Stephens G L, Fu Q. The sensitivity of domain-averaged solar fluxes to assumptions about cloud geometry. Q J R Meteorol Soc, 1999, 125:2127–2152
Li J. Accounting for unresolved clouds in a 1D infrared radiative transfer model. Part I: Solution for radiative transfer, cloud scattering, and overlap. J Atmos Sci, 2002, 59:3302–3320
Liang X Z, Wang W C. Cloud overlap effects on general circulation model climate simulations. J Geophys Res, 1997, 102:11039–11047
Hogan R J, Illingworth A J. Deriving cloud overlap statistics from radar. Quart J Roy Meteor Soc, 2000, 128:2903–2909
Barker H W. Overlap of fractional cloud for radiation calculations in GCMs: A global analysis using CloudSat and CALIPSO data. J Geophys Res, 2008, 113:D00A01
Räisänen P, Barker H W, Khairoutdinov M, et al. Stochastic generation of subgrid-scale cloudy columns for large-scale models. Q J R Meteorol Soc, 2004, 130:2047–2068
Barker H W, Räisänen P. Radiative sensitivities for cloud structural properties that are unresolved by conventional GCMs. Q J R Meteorol Soc, 2005, 131:3103–3122
Räisänen P, Barker H W, Cole J N S. The Monte Carlo Independent Column Approximation’s conditional random noise: Impact on simulated climate. J Clim, 2005, 18:4715–4730
Pincus R H, Klein S A. Using stochastically generated subcolumns to represent cloud structure in a large scale model. Mon Weather Rev, 2006, 134:3644–3656
Räisänen P, Järvenoja S, Järvinen H, et al. Tests of Monte Carlo independent column approximation in the ECHAM5 atmospheric GCM. J Clim, 2007, 20:4995–5011
Morcrette J J, Barker H W, Cole J N S, et al. Impact of a new radiation package, McRad, in the ECMWF Integrated Forecasting System. Mon Weather Rev, 2008, 136:4773–4798
Shi G Y. Atmospheric Radiation (in Chinese). Beijing: Science Press, 2007. 302–318
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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). https://doi.org/10.1007/s11430-012-4489-x
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DOI: https://doi.org/10.1007/s11430-012-4489-x