冬、夏季热带及副热带穿透性对流气候特征分析   总被引：2，自引：0，他引：2  

刘鹏  王雨  冯沙  李崇银  傅云飞 《大气科学》2012,36(3):579-589

文中利用热带测雨卫星 (TRMM) 搭载的测雨雷达 (PR) 1998~2007年的探测结果, 就热带及副热带地区穿透性对流的频次、条件降水强度及垂直廓线等特征进行了分析。研究结果表明: 深对流和穿透性对流都主要发生在热带辐合带 ( ITCZ)、南太平洋辐合带 (SPCZ)、亚洲季风区、20°N以南的非洲以及美洲等地区, 它们的空间分布具有明显的地域性和季节变化特征, 而且陆地深对流更容易发展成为穿透性对流, 但绝大部分地区的穿透性对流频次不超过0.2%。对穿透性对流条件降水强度的分析表明, 热带及副热带大部分地区的穿透性对流条件降水强度在10 mm/h以上, 且洋面的条件降水强度要比陆地大, 但由于其频次较小导致其对总降水的贡献并不大。尽管深对流和穿透性对流降水廓线的外形比较相似, 但相同的高度, 深对流的降水强度要比穿透性对流偏小, 而且这种差异随海陆和纬度的不同而有所区别。此外, 热带地区 (15°S~15°N) 冬、夏季深对流和穿透性对流降水廓线都只存在较小差异, 并没有显示出明显的季节变化。  相似文献   

Dangerous fogs on the territory of Georgia     

E. Sh. Elizbarashvili  O. Sh. Varazanashvili  N. S. Tsereteli  M. E. Elizbarashvili  Sh. E. Elizbarashvili 《Russian Meteorology and Hydrology》2012,37(2):106-111

The statistical structure of dangerous fogs with the visibility of less than 50 m is studied using the observation data of 50 meteorological stations in Georgia for the period of 1961–2006. The contribution of dangerous fogs to the total number of foggy days is estimated. The number of days with dangerous fogs and their duration in different regions of the country are determined and the empirical functions of their distribution, sizes of areas of their expansion, temperature regime, and peculiarities of annual variations are studied.  相似文献   

Possible mechanism of ozone depletion on ice crystals in the polar stratosphere     

Yu. E. Belikov  S. Sh. Nikolaishvili 《Russian Meteorology and Hydrology》2012,37(10):666-673

Developed is a new mechanism of photochemical reactions taking account of the dipole interaction between the molecules and the ??sharp?? inhomogeneities of electrified ice crystals in polar stratospheric clouds. This mechanism enables to explain the ozone depression formation during the winter-spring period in the polar stratosphere.  相似文献   

中国南方地基雨量计观测与星载测雨雷达探测降水的比较分析   总被引：7，自引：2，他引：5  

刘鹏  傅云飞  冯沙  曹爱琴  杨元建  李天奕  自勇 《气象学报》2010,68(6):822-835

利用热带测雨卫星(TRMM)上搭载的测雨雷达(PR)探测结果和中国40°N以南地区约430个台站雨量计观测结果,分析研究了1998-2005年中国南方地区这两种降水资料气候分布的异同.研究结果表明两种降水资料在2.5°空间水平分辨率上,所描述的中国南方降水率气候分布在多年年平均和季平均上具有较好的一致性,但在降水率极值和极值区范围大小等细节上两者还存在一定的差异,主要是地面雨量计结果相对PR结果偏高,其中中同南方50%以上地区两者相差在1 mm/d以内、30%的地区两者相差在1-2 mm/d,夏季差异可超过2 mm/d.对两种降水资料差异的原因分析表明,地面雨量计空间分布密度是影响两者差异的决定性因素,当格子内雨量计超过6个时,两者的相关系数大于0.7;夏季两种降水资料的相关性都比其他季节差,不论格子内的雨量计数量多与少;对流降水多发地区,两种降水资料之间的差异大于层云降水多发地.利用PR探测结果对夏季青藏高原多年月平均降水率分布及高原东、西部的降水特点的分析表明,6月高原东部出现2 mm/d左右的降水区,而在7和8月1 mm/d的降水区域基本覆盖了除高原西部以外的整个高原,其中高原中部地区出现降水率近3mm/d的大值区.月降水距平的时间演变表明,高原降水偏少月份要多于偏多月份.  相似文献   

ＣＬＭ３０对中国区域陆面过程的模拟试验 及评估Ⅱ：土壤湿度   总被引：5，自引：2，他引：3  

陈海山  熊明明  沙文钰 《气象科学》2010,30(5):621-630

利用NCAR公用陆面模式（Community Land Model 3.0,CLM3.0）及普林斯顿大学1948—2001年1°×1°、3 h一次的全球大气近地面强迫资料,对中国地区1948-2001年的土壤温度进行了off-line模拟试验,通过对模拟结果和全国台站观测土壤温度资料的对比,评估了CLM3.0对中国区域不同层次土壤温度的模拟能力。结果表明：模式能模拟出中国地区多年平均土壤温度的空间分布型,除部分地区模拟比观测偏高外,模式模拟的土壤温度普遍偏低;模式能较好地反映出中国地区土壤温度的年际变化,对4月的模拟稍好于7月。对于划分的8个子区域,东部区域模拟好于其它各区,除高原一带外,表层的模拟均好于深层;模式基本能抓住土壤温度的变化趋势,而且模拟出了7月长江流域以南地区土壤温度显著降低这一趋势,但模拟的趋势比观测有所偏弱。  相似文献   

Peculiarities of surface air temperature variations over the Far East regions in 1976–2005     

T. A. Shatilina  G. Sh. Tsitsiashvili  T. V. Radchenkova 《Russian Meteorology and Hydrology》2010,35(11):740-743

Peculiarities are investigated of the air temperature variation tendencies at some stations of the Far East in 1976–2005. The estimate of linear trend equation coefficients is computed according to the air temperature observation data using the least squares method. It is demonstrated that the air temperature trend in northern regions possesses a small probability at small values of residual variability. In the southern regions, the trend significance increases for almost all seasons at small values of residual variability. At midlatitude stations, the trend significance in January and February decreases considerably due to the large values of residual variability.  相似文献   

Thermodynamic regime of Svecofennian (1.9 Ga) metamorphism of the Umba nappe of the Lapland collisional orogen     

V. A. Glebovitskii  Sh. K. Baltybaev  O. A. Levchenkov  E. V. Kuz’mina 《Petrology》2009,17(4):331-351

Thermodynamic regime of culmination phase of high-grade metamorphism of the Umba nappe (Lapland allochthon) was studied, and peak metamorphic monazite was dated. Based on calculation of end member reactions, the metamorphic assemblages of aluminous gneisses from the upper and lower parts of the nappe are close to equilibrium. The metamorphic conditions of the rocks are estimated to be about 800°C and 7 kbar in its upper part and 9 kbar in its lower part. The formation of orthopyroxene-sillimanite aggregates points to increasing pressure and temperature at the prograde stage of PT path, whereas cordierite rims mark the onset of decompression and cooling. The pressure difference of 2–2.5 kbar identified by thermobarometric methods between aluminous gneisses from the upper and lower parts of the Umba nappe corresponds to a depth gradient about 7.5 km, which agrees with approximate thickness of the Umba nappe. The study of the eclogitelike rocks developed after the rocks of the Paleoproterozoic Kolvitsa gabbronorite massif made it possible to trace the P-T evolution of metamorphsim: the temperature peak of granulite stage (11 kbar, 860°C) was followed by pressure increase (up to 14 kbar and more), and then decompressional cooling due to the exhumation of the Por’ya Guba nappe together with the Kolvitsa Massif. The U-Pb monazite age of 1904 ± 3 Ma obtained for aluminous gneisses from the upper part of the Umba nappe corresponds within error to the timing of metamorphic events determined from metamorphic zircon in the anorthosites of the Kolvitsa Massif (1907 ± 2 Ma) and zircon from aluminous gneisses in the melange zone (1906 ± 3 Ma). These isotopic data confirm the conclusion of simultaneous high-pressure granulite metamorphism in the upper and lower portions of the Umba nappe.  相似文献   

Lower Oligocene Calc-Alkaline Spessartitic Lamprophyres from Central Iran (East of Anarak Area); an Evidence from the Eastern Branch of Neotethys Subduction-Related Mantle Enrichment     

Nazari  Gh. H.  Torabi  Gh.  Arai  Sh.  Morishita  T. 《Geotectonics》2019,53(6):786-805

Geotectonics - The Lower Oligocene Kal-e-kafi (East of Anarak, Central Iran) lamprophyres occur as stocks and dikes, which cross-cut the Eocene volcanic and Cretaceous sedimentary rocks. The...  相似文献   

A Long-Term Forecast Model of Spring Runoff: The Case of the Belaya River     

Vasil’ev  D. Yu.  Vodopyanov  V. V.  Zayzeva  G. S.  Zakirzyanov  Sh. I.  Semenov  V. A.  Sivokhip  Zh. T.  Chibilev  A. A. 《Doklady Earth Sciences》2019,486(2):724-727

Doklady Earth Sciences - The results of long-term forecasting of the spring runoff in the Belaya River basin based on the water-balance model are presented. The structure and parameters of the...  相似文献   

Characteristics of asthenosphere distribution in the eastern segment of the Central Asian Orogenic Belt revealed by long period magnetotelluric (LMT) detection     

Jianqiang Kang  Jiangtao Han  Wenyu Liu 《《地质学报》英文版》2018,92(Z1):118-118

  相似文献