Abstract:As the first global active survey satellite of cloud properties,the CloudSat satellite was successfulll launched in April 28,2006.Firstly,this paper introduced the equipment,operating parameters,operation mode,data products and the "A-Train" satellite constellation.The CloudSat satellite supports a W-band(94 GHz/3 mm) cloud profile radar.It can cut the clouds and get so much new meteorological data,including the macro-and micro-physical parameters.Secondly,the paper concluded the initial results of typical weather and cloud observed by the CloudSat satellite.The first 3-D image of the storm clouds over the Antarctic was gotten;the state of the snowfall cloud development and structure was gotten from the first image of the snowfall cloud;the global hydrometeor distribution was analyzed by the CloudSat statistical data.A comparison has been made between the precipitation radar on the TRMM satellite and the cloud radar on the CloudSat satellite,and the fine vertical structure of different kinds of clouds can be received.Based on the CloudSat satellite data downloaded,the macro-and micro-structures of cloud were preliminarily analyzed in the different weather conditions,and the evolution and vertical structure of the clouds near a typhoon eye can be seen.The hierarchical structure of cloud and the vertical distribution of different phase cloud also can be seen by analysing the vertical profile of the stratiform clouds.In short,the CloudSat satellite can provide us a strong platform to research the cloud structure.

Abstract:A nonlinear projection of the tropical Pacific sea surface temperature anomalies(SSTA) onto the Northern Hemisphere winter sea level pressure field(SLP) anomalies by nonlinear canonical correlation analysis(NLCCA) was performed to investigate the nonlinear association between ENSO and the Northern Hemisphere winter atmospheric circulation anomaly.The NLCCA results reveal that,from the extreme cold period to the extreme warm period,the responds of the Northern Hemisphere winter atmospheric circulation anomaly to ENSO is a straight line and a parabola,explaining that the response of winter circulation anomaly over Northern Hemisphere to ENSO is composed of a linear part and a nonlinear part with the quadratic character.Both the cold and warm periods of ENSO will make Iceland Low weaker,and the variations of Siberian High,Northern America High and Northern Pacific High are asymmetric with the SSTA,proving the nonlinear responds of winter atmospheric circulation anomaly over Northern Hemisphere to ENSO.The nonlinear response of Iceland Low to ENSO is the strongest,while the response of Aleutian Low to ENSO is mainly linear.

Abstract:A dust event that passed over Dalian(38.90°N,121.63°E) on November 6,2005 has been observed by a micro-pulse lidar(MPL) of China-Korea cooperative Dust Monitoring Program.It is found that the dust layer extended upwards from 1 to 2 km above the ground level,with a peak extinction coefficient of 1.08 km^-1.Additionally,the aerosol optical depth(AOD) of this dust air mass accounts for 47% of that for the whole air column.The extinction coefficient on the ground surface increased to 0.23 km^-1 when the dust entered to the atmospheric boundary layer in Dalian.The dust aerosol layer related closely with the vertical distribution of the meteorological parameters which was characterized by lower RH associated with the arid condition in desert area.The mass concentration of PM₁₀ increased to 1678.9 μg/m³ when the dust air mass affected Dalian,which is in good agreement with the temporal evolution of the ground extinction coefficient retrieved from the MPL data.The conversion scale between the mass concentration of PM₁₀ and the ground extinction coefficient varied in the range of 1.94 to 6.50 mg·m^-3·km^-1.

Abstract:The rainstorm in Anhui Province on July 13th,2001 is simulated by numerical model ARPS(Advanced regional prediction system) and its 3D-VAR(3-dimensional variational data assimilation) system developed by CAPS(Center for analysis and prediction of storm) and Doppler radar data in China.Assimilation experiments are carried on by adding Doppler radar data at 10 and 30 minutes intervals,respectively,with the former results as the followed one’s initial fields adjusted continuously.It is found that the winds and water vapor fields are obviously improved after inducing Doppler radar data,especially the 3-h precipitation simulations.And more times radar data induced,better the forecast simulations.

Abstract:It is comparied between two infrared cloud-cleared radiance retrieval approaches,i.e.collocated infrared and microwave measurement and collocated infrared imaging and sounding measurement.It is found that AIRS/MODIS cloud-cleared radiance approach perform better than AIRS/AMSU cloud-cleared radiance approach relative to the collocated MODIS clear averaged radiances.The temperature and total precipitable water retrieved by AIRS/MODIS cloud-cleared radiance approach fit well with that objectively analyzed by ECMWF(European Center of Medium-range Weather Forecasts).Preliminary results show that the two approaches,though essentially different,are both effective and complementary.When the microwave measurements are unavailable,the synergistic imaging/sounding approach is the only reliable one,which can indirectly use the cloud-contaminated infrared measurements.

Abstract:Based on 1961-2006 daily precipitation data during flood season(from May to September) of 33 stations in Chongqing,by defining the extreme rainfall threshold,study is performed of the annual gross precipitation and the temporal/spatial distribution features of each station in the study period,results show that in flood season Chongqing has the significant spatial distribution differences in extreme rainfall,and the consistently abnormal characteristic is the main spatial mode;Chongqing can be divided into five regions;and the extreme rainfall covers a very large proportion of the total rainfall in each region;and from a long-term trend,the precipitation in Chongqing area does not show significant increasing or decreasing trend,and for the recent 46 years the periodic oscillations of extreme precipitation are dominated by 2-3-year,5-year periods,and about 11-year period.

Abstract:Based on black carbon aerosol(BC) observations in Lanzhou,Dunhuang and Tazhong stations,as well as PM10 and aerosol optical depth(AOD) observations from the related stations during March to May 2006 in the northwestern China,the black carbon aerosol distribution is studied.The results show that the BC mass concentration is the highest in Lanzhou compared with Dunhuang and Tazhong by a mean value of 2.22 μg/mm³,1.89 μg/mm³ and 2.07 μg/mm³ respectively.This value is smaller than that in Beijing,Shanghai and Zhujiang Delta,but higher than that in Waliguan atmospheric background station.The diurnal variation of BC mass concentration has an obvious peak and valley characteristics with lower value at 12:00-14:00 BST(Beijing Standard Time) and higher value at 08:00-20:00 BST,which mainly depends on the diurnal variation of BC sources and its turbulent exchange in the surface layer,and the diurnal variation of atmospheric stability.The correlation coefficient between BC and PM₁₀ mass concentration is very small in the northwestern China with the highest correlation coefficient(only 0.24) of hourly observations in Tazhong,indicating that BC mainly comes from human activity and the main composition of PM₁₀ is sand dust aerosol.Once the sandstorm passes the observational station,the BC mass concentration will increase more than 50% for the absorbing characteristic of sand dust aerosol,and BC carried by the abundant sand dust only occupy a small proportion.

Abstract:The nonlinear Kelvin and Rossby waves of atmosphere in low latitudes are studied.Using the Wentzel-Kramers-Brillouin(WKB) method,it is found that the interaction between two wave packets is governed by the coupled nonlinear Landau equations with complex coefficients.Numerical calculations show that the wave amplitudes change and the wave widths become narrow after the collision of two solitary waves.The results indicate that the nonlinear interaction between Kelvin and Rossby waves may be one of causes,which inspire the severe convective weather in low latitudes.

Abstract:By using Chinese station daily observation data,the climate change features of the farming-grazing zone in northern China in the past 56 years(1951-2006) have been analyzed.It is concluded that the annual precipitation presents obvious interannual and interdecadal variations in the zone with a remarkable decrease trend in the recent 10 years.The annual mean temperature has little change before 1990s,but becomes warmer persistently after 1987,which is consistent with the change trends in the globe and China.The changes of rainfall and temperature show the obvious seasonal and regional differences.Based on the above analyses,the future projection during 2001-2030 has been undertaken by the nested GCM(global coupled model) and RCM(regional climate model) under the IPCC SRES A2 emission scenario.Relative to the model climate field(1961-1990),the possible change trends of rainfall and temperature in the zone in future 30 years have also been analyzed.The results indicate that the air surface temperature will keep on increasing in the whole region with annual mean increasing 0.3 ℃.Due to the minimum temperature increases larger than the maximum temperature,the daily range of temperature is expected to decrease in the future.Precipitation is expected to increase with less extent.Drought threaten in the up-reach of Huanghe River still might be very heavy in the future.

Abstract:Based on 531-yr(1470-2000) drought/flood level data of 38 stations in eastern China,the EOF analysis is used to achieve three primary drought/flood types:Huanghe-Changjiang homogeneous anomaly pattern(Pattern Ⅰ),Huanghe-Changjiang contrary anomaly pattern(Pattern Ⅱ),and Huanghe-Jianghuai-South China alternate anomaly pattern(Pattern Ⅲ).Then six summer drought/flood patterns in eastern China are defined according to the positive and negative phases of above three patterns.In view of the instance that a single index can not depict the drought/flood anomaly distribution accurately,this paper utilizes combined three-index to compartmentalize annual drought/flood pattern in term of the most noticeable feature,and then presents a new table of 531-yr summer drought/flood pattern in eastern China.Finally,a comparison is made between the decadal frequencies of six drought/flood patterns and the EOF time coefficients,showing that they have preferably coherence,which verifies that,to a certain extent,compartmentalization is reasonable on the whole.

Abstract:Based on the annual hail-day records of 614 stations in China from 1971 to 2000,spatial and temporal features were discussed.Results show that the annual hail days in China decreased apparently in recent 30 years,and hails occur more frequently in the Tibetan Plateau with annual hail days more than 10 days.Over the Yangtze River valley and South China,hails often appear during February to April,but in other regions in May to September.As a result,hails occur least/most frequent in the winter/summer.Moreover,hails occur typically in the afternoon and early evening,but in the Yangtze River valley and South China,it can happen at any time.

Abstract:Based on the daily temperature data during January 1951 to April 2007 in Nanjing,the change trends and characteristics of mean temperature,yearly maximum temperature,yearly minimum temperature,cold accumulated temperature and hot accumulated temperature in Nanjing are analyzed.The change of cold winter,warm winter,cool summer,and hot summer are discussed.The results show that the mean temperature tends to rise obviously,especially in spring and winter with the former larger than the latter.The yearly minimum temperature and cold accumulated temperature tend to rise remarkably,and the yearly maximum temperature and hot accumulated temperature tend to descend slightly.In recent 56 years,the all cold winters have appeared before 1980s and the warm winters are frequently observed after 1990s.The spring comes earlier with the time lengthen a little.The length of summer has prolonged for about four pentads.The length of autumn has shortened for about two pentads with starting time about ten days later.The length of winter has shortened for about 3 pentads.

Abstract:We simulated and extracted the characters of radial velocity data of the low-attitude strong wind using the software Matlab,developed an algorithm for identifying low-attitude strong wind axis based on these characters,and finished the design of a identifying module.Using the Doppler weather radar data of a heavy rain accompanied with a low level jet in Anhui province on July 10,2003,we tested the module,and compared the result of automatic identification with that of experience estimation and found that this module is good in identifying the low-attitude strong wind axis.

Abstract:This paper studies an unsteady thermally coupled Stokes problem.Existence of a weak solution is established under some conditions by Faedo-Galerkin method.The estimate of the weak solution which depends on the initial and boundary conditions is established to prove the uniqueness.

Abstract:Separation of CO₂ from the gas mixture was performed by a module with the hydrophobic PP(polypropy lene) microporous membrane and using the deion water.Effects of gas and liquid flowrates,CO₂ concentration and operation temperatures as well as membrane configuration on overall mass transfer coefficient were investigated.A mathematical model was presented by correlating the resistance in series and the mass differential equation.Mass transfer was simulated under the various operation conditions.Results show that the change of hydrodynamics in the module can enhance mass transfer finitely.Overall mass transfer coefficient can be increased with the increase of CO₂ concentration.Membrane modules with high porosity possess a high mass transfer coefficient.Elevation of operation temperatures can accelerate the diffusion and enhance the mass transfer.Partial micropores may be wetted at higher operation temperatures.The operation process of hydrophobic hollow fiber membrane module can be better simulated by the model.The modeling results are in good agreement with experiments.

Abstract:Based on the monthly mean precipitation data at 160 stations of China and 59 stations of Jiangsu during 1961-2004,the Lamination Cluster Method is firstly used to divide total Jiangsu region into three subregions,i.e.the north to Huaihe River(Region Ⅰ),the in-between of the Yangtze River and the Huaihe River with their riverside areas(Region Ⅱ),and the southern Jiangsu(Region Ⅲ).On this basis,the investigation is focused on the spatial and temporal variations of summer precipitation anomalies over the three subregions as well as their possible relationships with other areas in China.Results show that the summer precipitation anomalies over the three subregions exhibit remarkable interannual and interdecadal variations,but the variations are inconsistent in different subregions,especially the interdecadal variation with very evident difference between the south and north to Huaihe River.The quasi 5-yr and quasi 9-yr interannual variations of summer precipitation anomaly exist in most areas south to Huaihe River with an increasing interdecadal trend appreciably,and the 12-15-yr interdecadal variation does in the regions north to Huaihe River and the southern Jiangsu,meanwhile an decreasing interdecadal trend occurs in the north to Huaihe River.Moreover,the summer precipitation anomaly in Jiangsu is usually out-of-phase with that in Hetao area,the northern North China and the southern South China.

Abstract:The three-dimensional wind fields of the heavy rain on September 19th,2005,in middle Shandong Province are retrieved and explored with ground-based dual-Doppler radar data and conventional observations.Results show that the heavy rain is caused by the cumulus-stratus mixed cloud with the shear and convergence lines in the low level.Development of the small-scale convective cell is induced by the mesoscale structure of wind field,and the cells nested in the large stratus are organized to echo bands.Along with cold air diffusing southeastward,the mesoscale structure of wind field mainly locates in the layer below 4 km.Kinetic factors of the cell with a strong echo are shear lines in the low and middle levels and cold air diffusion.Moreover,it is found that the marked vertical motion happens in the strong echo area.The wind mesoscale structure plays an important role in initiating and maintaining the heavy rain.

Abstract:Based on the annual mean temperature and precipitation data at the 38 meteorological stations over Tibet from 1971 to 2005,the net primary production(NPP) is computed by Thornthwaite Memoriai Model.The spatial distributions,interannual and interdecadal variations of the NPP are analyzed,and the influences of climate changes on NPP are discussed.The results show that the distribution of NPP is characterized by a remarkable regional feature,i.e.decreasing from the southeastern to the northwestern of Tibet.During last 35 years,the reduction of NPP was insignificant in southwestern Ngari district and Nyalam county,and it ranged from 11.9 to 314.2 kg·hm^-2·(10a)^-1,with the largest in Purang county.In other districts of Tibet,NPP has increased and the increment ranged from 26.8 to 459.8 kg·hm^-2·(10a)^-1,with the largest in Lhasa.Also,the results show that NPP has increased interdecadally in Nyingri district,northern Chamdo district and Nakchu district,but decreased in southwestern,Nyalam county and Gyantse county.On an average over the whole Tibet,the NPP changed interdecadally.When the cold and dry climate occurred in the 1970s,the NPP was lower;and when the warm and wet climate appeared in the 1990s,the NPP was higher.Under climate change scenarios,the warm and wet climate would benefit the NPP with an average increment of yield by 6% to 13% over Tibet,while the cold and dry climate would have an adverse impact on NPP with an average reduction of yield by 6% to 14%.The future climate over Tibet would become warm and moist,and the NPP would also increase by 11% to 26% in 2050.

Abstract:The characteristics of overcurrents(OC) and overvoltages(OV) in electrical system protected by coordinated two-stage lightning surge protective devices(SPD)(the first is a spark gap,the second is a metal oxide varistor) were researched and transient Kirchhoff equations of OV protected by two-step circuits were built.The OC and OV of every SPD,conducting cables between SPDs(or decoupling devices) and loads were calculated and simulated.Waveforms of initial lightning surge,distributing currents in every SPD and load and load voltage varying with time were obtained according to the equations.Therefore,the features of OV on load and OC distributed in the circuit,Which were protected by coordinated two-stage SPD,were concluded.The results are advisable to provide a theoretical method for the multi-stage protection against lightning surge current,and also can be reference for the design of lightning protection engineering in electrical system.