| Because of the various types of clouds in the atmosphere and their uneven temporal and spatial changes,the balance of the Earth-gas system in different regions have different situations.In the numerical simulation of the global Climate Model(GCMS),the radiation revenue and expenditure of the atmosphere-earth system contains a great uncertainty because of the imprecision of the parameterization scheme of the macro-microscopic physical process of the cloud,which makes the model have obvious error in simulating and evaluating the climate feedback effect of cloud.Therefore,understanding the temporal and spatial variation of cloud can provide an effective reference for parametric scheme of climate models.However,in the researches of the physical mechanism of the generation and variation of clouds,there is little understanding of the variations of the various forms of tropical deep convective clouds and their complex structures.The distinction among different types of tropical deep convective clouds and the relationship between their physical properties and large-scale environmental conditions are the important step to further improve the parameters of cloud in climate models.In this paper,the global cloud occurrence distribution is studied by using the joint observation data of the A-train satellites,the identification and classification algorithms of the tropical deep convective cloud are developed.Furthermore,the macroscopic and microscopic physical properties of the different forms of the deep convection cloud are compared.Finally,the relationship between the tropical deep convective clouds and the large scale environmental conditions is discussed with the ECMWF and MERRA-2 analysis data.The main results of this paper are as follows:(1)Based on the CloudSat and CALIPSO combined level-2 cloud classification products,this study analyzes the geographical distribution of cloud occurrence,the seasonal variation of zonal vertical distribution and the probability of cloud layer distribution in eight types of clouds and three phases of cloud from March 2007 to February 2010.The distribution pattern of cirrus clouds is similar to deep convective cloud,mainly concentrated in the western Pacific warm pool,the global monsoon region and the equatorial convergence zone.The distribution patterns of cirrus cloud and deep convective cloud are consistent with the seasonal movement of the wind belts.The stratus and stratocumulus are mainly distributed in the middle-low latitude non-monsoon region and the ocean surface of middle-high latitude.The distributions of altocumulus and altostratus have obvious difference between sea and land.The distributions of nimbostratus and cumulus have obvious latitude difference.The distribution pattern of ice cloud is similar to cirrus clouds,and their cloud height decreases with latitude.The distribution pattern of water cloud is similar to that of layer cumulus,which is distributed evenly in 2 km height.The mixed-phase cloud is concentrated in high latitude region and equatorial convergence zone.In the latitude distribution,the mixed-phase cloud is concentrated on the arc Zone from altitude of 0-10 km.The stratiform clouds appear more in the form of multiple layers of cloud.The cumuliform clouds appear more in the form of single and double clouds.The stratiform clouds with cloud overlapping phenomenon occurs more than the cumuliform clouds significantly.The distribution characteristics of the cumuliform clouds and stratiform clouds are consistent with those of convective precipitation and stratiform precipitation.These results are consistent with that of satellite observations of different types of precipitation.They can be provided for the climate model cloud cover diagnosis.(2)The Cloud Sat/CALIPSO cloud products combined with the Aqua MODIS radiation products and the Aqua AMSR-E surface precipitation and sea-table temperature products from January 2009 to December 2010,are used to identify the separated deep convective clusters(DCCs),connected DCCs and mesoscale convective systems.Characteristics of precipitation characteristics and cloud ice water content(IWC)vertical distribution of these three types of DCCs are compared and analyzed.In summary,separated DCCs and MCSs occur frequently over East Asia,while connected DCCs are favored over the warm pool of the West Pacific in June-August and over South America in December-February.A larger convective rain area with a low convective rain rate is typically formed by connected DCCs.However,connected DCCs can develop an IWC at 10-15 km as large as that of MCSs.This condition may be caused by notably large anvil-stratiform clouds connected with multiple deep convective cores.Connected DCCs can easily be confused with MCSs if one focuses on the cloud top brightness temperature in the horizontal view.More differences among the cloud radiative effects should be investigated in future studies by climate researchers.(3)based on the observational data of the A-train satellites from January 2009 to December 2010,the relationship between the tropical deep convective clusters and the sea surface temperature(SST),the convective available potential energy(CAPE)and the vertical wind shear is discussed in combination with the ECMWF and MERRA-2 analysis data.For the effect to cloud morphological characteristics,vertical wind shear has a promotion to horizontal scale extension of DCCs nonetheless severe vertical wind shear impede geometrical cloud top height of DCCs.On the other side,adequate CAPE and SST provide energy to raise a great cloud top height.However,with a great horizontal stratiform-anvil cloud,CAPE and SST is restrained in a low level because of lessen heating from solar radiation.For microphysical process of cloud,strong convective precipitation which engender downdraft to drag down big ice particles force a declination of SST and CAPE and advancement of vertical wind shear.Otherwise,prominent precipitation,CAPE and SST will be retrained and cloud top height will get lower with smaller ice particles in a low altitude with intense vertical wind shear. |
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