lmd_Seze1991_abstracts.html

1991 .

W. Yu, G. Sèze, H. Le Treut, and M. Desbois. Comparison of radiance fields observed by satellite and simulated by the LMD general circulation model. Dynamics of Atmospheres and Oceans, 16:147-165, October 1991. [ bib | DOI | ADS link ]

A time series of International Satellite Cloud Climatology Project (ISCCP) B2 data has been used to study the spatio-temporal variability of cloud radiance fields and to compare it with similar diagnostics obtained from a numerical simulation with the Laboratoire de Météorologie Dynamique general circulation model (GCM). We first compare zonal means of the observed and simulated fluxes: the largest differences appear mainly above land, probably due to a diurnal cycle effect. A computation of the cloud radiative forcing is made to distinguish model errors in the clear sky or in cloudy areas: it shows that the radiative effect of the simulated clouds is generally smaller than that of observed ones. The influence of the spatial resolution on the variability of the visible and infrared radiance fields is examined. The results show that the variability due to the better spatial resolution of the satellite data cannot be simulated by the GCM; however, the variability of the simulated radiances is comparable to that of the satellite data when they are spatially averaged on the GCM mesh. The temporal variability of the spatially averaged observed and simulated radiances has a similar spatial distribution but the model results are slightly smaller. The memory of the precedent state shown by the autocorrelation function is longer for the GCM than for the observation. However, the periods obtained by a spectral analysis in the mid-latitude regions are approximately the same in the observation and the simulation.

G. Sèze and W. B. Rossow. Effects of satellite data resolution on measuring the space/time variations of surfaces and clouds. International Journal of Remote Sensing, 12:921-952, May 1991. [ bib | DOI | ADS link ]

G. Sèze and W. B. Rossow. Time-cumulated visible and infrared radiance histograms used as descriptors of surface and cloud variations. International Journal of Remote Sensing, 12:877-920, May 1991. [ bib | DOI | ADS link ]