| Along with the widespread application of satellite data, lots of scholars have made in-depth study about the vertical structure of precipitation. But due to the lack of observation data, the cognition of atmospheric temperature and humidity inside precipitation clouds is still insufficient up to now.To cure the above problems, two topics are included in this paper. The first one is about climatic regionalization of China, in order to understand the regional differences of atmospheric background field. Then we generate a quasi-space-time synchronization data set of precipitation relative to the profiles of temperature and humidity by merging Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and The Integrated Global Radiosonde Archive (IGRA) data from1998to2012. Based on this data set, the characteristics of precipitation, temperature, humidity and convectively available potential energy (CAPE) in different rain type and different monsoon region are investigated. The results obtained in the present study can be summarized as follows.(1) The atmospheric temperature and humidity condition of different climatic zones in China are presented.In this paper China is divided into eight different climatic zones. The lower latitude areas have higher surface temperature, greater temperature lapse rate and lower temperature of stratosphere. The temperature profiles in different areas of same latitude are essentially same in the south of38°N, and the temperature signals exist meridional differences in the north of38°N. The atmosphere humidity has remarkable regional characteristics, the southern regions and Sichuan Basin are wetter, but the inland regions are drier. The regional differences of temperature and humidity change with season. The regional differences of temperature is maximum in winter (>25℃) and minimum in summer (<5℃). At the same time, the summer (>50℃) regional differences of humidity is larger than winter (<25℃).The near surface temperature is higher at night, and the temperature difference between day and night is bigger in the inland areas(-8.8℃) than the coastal areas(-3℃). The stratosphere temperature in the morning is higher at most regions, meanwhile the stratosphere temperature difference between day and night is higher in lower latitude. And the inland diurnal variation of humidity is higher than coastal areas. Temperature changes mainly appear in close to the ground, with temperature difference between winter and summer over35℃, and the temperature above500hPa is almost invariant. The inland regions are dry all the year round, the southern regions are wet in lower atmosphere, but dry in the middle and upper atmospheres in winter with relative humidity<20%. Region1-5are wetter before2005and drier after2005. And the separations of wet and dry at Region6-8appear in2002.(2) The characteristics of temperature, humidity and wind in different precipitation are presented.Results of case study indicate that the precipitation of Gulin station and Quxian station has strong ascending motion and greatly increasing convective cells. The surface temperatures are higher than24℃when precipitation occurs, and the lapse rate about tropospheric temperature is5.8℃/km The deep intense convective precipitation is consistent with the moist air in the whole troposphere, large CAPE and weaker high-level wind, as well as the atmospheric type of potential instability.The precipitation of Sheyang station and Hongjia station is weak, with rain top height below8km and near surface radar echo below40dBz, meanwhile more than half of the radar echo above5km only reached20dBz. While the stratiform precipitation is accompanied by the surface temperatures lower than20℃and the stronger high-level wind. CAPE does not exist in the stratiform precipitation. The air humidity under500hPa is large and significantly reduces with height.(3) The different characteristics of precipitation, temperature, humidity and wind in EASM and ISM are presented.It is also found that the structures of precipitation have prominently distinctions between EASM and ISM. The precipitation in EASM is heavier, with the higher rain top reaching17km for the convection and12km for the stratiform precipitation, as well as large scale ice particles in the upper part of convection. The precipitation in ISM is weaker, with the rain top1km (convection) or2km (stratiform precipitation) lower than that in EASM.The significant difference of temperature between EASM and ISM occurs at the surface, with～4K higher for ISM because of the different detection time of radiosonde. Moreover, it is found that the atmosphere is wetter for the convective precipitation in lower atmosphere and drier in the upside, as well as that for the stratiform precipitation but with smaller deviation rate. Furthermore, the observations suggest that the CAPE is larger for the convective precipitation than for the stratiform precipitation. In addition, the CAPE value is larger for the precipitation in ISM than that in EASM. Both EASM and ISM precipitation can cool lower troposphere, warm middle troposphere and cool the tropopause. The most pronounced warming temperature signal appears in EASM, and ISM has larger cooling range.The weather is dominated by prevailing westerly (southwest) winds when rainfall occurs in EASM. In May, the wind is stronger, the air is drier and the precipitation is weaker, as well as smaller CAPE and non-significant warming/cooling temperature signals. The deep precipitations occur in the southern Tibet Plateau lacking of radiosonde stations in July and August of ISM, so the deep rainfall with rain top above14km does not appear in the study sample of these months. Before the outbreak of monsoon (May), the whole layer of atmosphere is dry, and accompanied by prevailing westerly and weak winds. From June to August, the weather is dominated by low-level prevailing westerly (northwest) winds and high-level prevailing easterly strong winds. Because the warm and wet air from Arabian Sea, the whole layer of atmosphere gets wetter. The CAPE value of ISM is lager. |
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