| The studies about cloud have carried out in the recent decades. However, thecloud is not divided in to the precipitating cloud and non-precipitating cloud. Thecharacteristics of cloud with the totally different underlying height surface andthe precipitation intensity need to be learned. In addition, weather model andclimate model generally can-not simulate well the cloud distribution. In order totreat the cloud process with increasing realism in the model, the microphysicalschemes have to be improved. In this paper, firstly, observations fromCloudSat/CALIPSO satellites and high spatial and temporal resolutionprecipitation dataset are used to analyze the vertical structure and microphysicsfeature of clouds with the different precipitation intensity and underlying heightsurface over the latitude zone which is along the Tibetan Plateau (90o-130oE and27o-33oN). Secondly, based on the observational analysis, the abilities of CMIP5models for simulating the clouds over the same latitude zone have been comparedand evaluated. Thirdly, the WRF is used to simulate the vertical structure and theevolution of hydrometeor species in the freezing rain over the Southern China in2008. Finally, a new microphysics parameterization is proposed. Its performanceis evaluated in the Beijing Climate Center Atmospheric General CirculationModel Version2.1(BCC_AGCM2.1). The main conclusions are summarized asfollows:1. The occurrence frequency of single-layer cloud dominates anddouble-layer is relatively more common in the multilayer cloud. In the rainlesscondition, the occurrence height of single-layer is higher in spring and summer,the top of cloud can reach the15km in summer. The occurrence height ofsingle-layer most concentrated between5and8km over the eastern TibetanPlateau, while the height between7and12km over the east coast and oceanarea.The cloud height is mainly below4km over the Sichuan Basin.Thesingle-layer most concentrated below5km over the underlying surface in autumnand winter. In addition, double-layer cloud is thin over the whole latitude zone;the lower layer is mainly between2and3km over the underlying surface. Theupper layer cloud most concentrated beween11and15km in summer, while the height is between7and10km in other seasons.2. The single-layer cloud is thicker when the surface precipitation occurred.The top of single layer cloud reaches around10km over the whole latitude zone;the height of cloud top is higher due to the convective activity in summer, while itis obviously lower in winter. Although the distribution of double-layer cloud issimilar, the lower layer is thicker.Nevertheless, the single layer and the lower ofdouble layer cloud becomes thicker with an increasing intensity of precipitation3. The analyses on the liquid cloud and ice cloud correspond to the verticalstructure of cloud. The height of liquid water content is located below8km alongthe latitude zone of Tibetan Plateau, while it is lower in winter. The content ofliquid cloud over the eastern Tibetan Plateau and Sichuan Basin is more than thecontent which is over the eastern area. In contrast, the eastern Tibetan Plateau ishigh value area of ice water content in all seasons. Although the ice cloud isobserved in the same layer, the distribution varies with the season. Ice cloud islocated between4and12km in spring,5-15km in summer and2-10km in winter.The ice content which is over the whole latitude zone in spring and summer ismore than other seasons. Compared to the rainless condition, the height of liquidwater content is approximately similar when the surface precipitation occurred.However, the high value region of liquid water is over the Sichuan Basin andeastern area. The ice water and liquid water content become larger with increasedprecipitation intensity.4. Comparing with the satellite observations, MRI-CGCM3，BCC-CSM1.1-mand MPI-ESM-LR models can simulate the phenomenon that single-layer anddouble-layer are prevailing over the latitude zone which is along the TibetanPlateau area, however, the occurrence frequency of multilayer cloud in othermodels is higher than observation. In the rainless condition, most models cannotsimulate the appropriate top and base of single-layer cloud, however,MPI-ESM-LR is better than MRI-CGCM3and BCC-CSM1.1-m. Most of CMIP5models overestimate the thickness of single-layer cloud in the rainy condition.MRI-CGCM3with the high resolution can exhibit the vertical structure ofdouble-layer cloud, while others overestimate the thickness of the upper layer. Allof the models underestimate the low-level cloud fraction. In addition, the icewater and liquid water are also underestimated in the rainless condition; latter isoverestimated in the rainy condition. Relatively low resolution MPI-ESM-LRalways shows the better results, it shows that the resolution is not the only factorto restrict the ability on the cloud simulation. 5. A freezing rain event between Jan11and Feb4in2008over southernChina is studied using the30km-mesh Weather Research and Forecasting (WRF)model simulations with four different microphysics schemes and CloudSatsatellite observations. This3-week-long freezing rain event, the temporalevolution of cloud microphysical structure and icing processing from Jan11toFeb4is also well simulated by WRF. In addition, WRF can capture the followingcharacteristics of an atmospheric vertical thermal structure for forming freezingrain: above-freezing temperature in the middle troposphere and below-freezingtemperature in the lower troposphere. The double-layer cloud is prevailing in thisdisaster; however, it is different from the satellite observation. The distribution ofsingle layer cloud is similar with the observation and becomes more concentratedas an increasing intensity of precipitation. However, the upper layer ofdouble-layer cloud is higher than the satellite observation.6. Based on the CloudSat data, a new microphysics parameterization isproposed. The performance is evaluated in the BCC_AGCM2.1. The result showsthat the new parameterization is more realistic in their proportion of ice water andliquid water. The liquid water bias is eliminated between the8and11km... |
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