Abstract:The 850 hPa wind field of ERA-40 reanalysis data from 1957 to 2002 is analyzed,showing that the lower level circulation in the northwest Pacific has an obvious interannual variability.This variability can represent the interannual variation of summer monsoon in the northwest Pacific,and impact on East Asia summer monsoon.Based on the observed Hadley SLP and SST data,diagnosis result shows that interannual variation of the northwest Pacific anomalous anticyclone(WPAC) has a good relation with sea surface temperature in North Indian Ocean in summer.And the relation becomes more obvious when deleting the linear Nino3.4 signal by the partial correlation method.On the other hand,the northwest Pacific anomalous anticyclone has not an obvious correlation with sea surface temperature in the southwest Indian Ocean in summer.The AGCM experiments demonstrate that there is a positive precipitation anomaly over north Indian Ocean when the north Indian Ocean SST is higher with a lower level anticyclone anomaly over the northwest Pacific.When the southwest tropical Indian Ocean is warmer,there are negative precipitation anomalies and anomalous easterlies over north Indian Ocean,and there is a weak anomalous cyclone over the northwest Pacific.The numerical experiment result tallies with the observations,indicating that the warmer summer SST in north Indian Ocean will lead to the lower level anomalous anticyclone in the northwest Pacific.

Abstract:By using the multi-year series of the circulation indices P(intensity) and C(center location) for the closed pressure system on the unit radius spherical surface,three characteristic quantities of annual system centers(around the climatological center C) are defined.1)Average distance r,which is defined as the weighted geometric average distance of the annual system centers C deviating from the climatological center C(i.e.the center location anomaly C′),is a measurement for distribution area of the system centers.2)Compression coefficient μ,which describes the extent of the annual system center distribution area deviating from circularity,is a measurement for distribution anisotropy of the annual system center locations.3) Maximum anomaly direction β,which indicates the main anomaly direction of system centers by using the angle that the system center maximum anomaly deviates from the east direction at C.The above three quantities of 100 hPa South Asian High(SAH) are calculated in June,July and August from 1948 to 2007,indicating that they can briefly and exactly describe the distribution characteristics of the center location anomalies on the spherical surface.According to the definitions of r,μ and β,they are also suitable for describing accurately the distribution characteristics of closed systems centers in the other meteorological element fields on the spherical surface.

Abstract:The characteristics of climate,hydrology,soil and vegetation in Mountain-Oasis-Desert System(MODS) directly reflect the impact of global change in arid zone.Taking Qiemo oasis ecosystem located in the south of Tarim Basin in the western China and the east of Kazakhstan in Central Asia for example,based on the analysis of MODS macro-characteristics in arid zone,the response of oasis ecosystem to global change is analyzed from the perspectives of the climate characteristics reflected by temperature and precipitation changes,and the landscape characteristics reflected by landscape indexes such as landscape diversity,landscape dominance,landscape evenness,and landscape fragmentation.Meanwhile,the regional response characteristics of global change are analyzed from the coupled relation among ecosystem factors and the ecosystem service value.Furthermore,the dissipation mechanism and the regulation approach of oasis ecosystem are proposed.

Abstract:Basing on the NCEP/NCAR 850 hPa averaged wind field in summer and the SST data of GISST from 1950 to 2002,the result that there is some nonlinear relationship between the tropical summer monsoon and ENSO is obtained by using the nonlinear canonical correlation analysis.Compared to strong El Nino year,there is an abnormal anticyclone over Australia with large difference in wind fields intensity,the location of the circulation center is westward and southward in strong La Nina year.When the SSTA is positive or negative anomaly,the nonlinear response presents as the intensity of the wind field;while the SSTA is changing from positive(negative) to negative(positive) departure,both the intensity and the circulation pattern represent nonlinear features clearly.The response of the tropical summer monsoon to ENSO obtained from the NLCCA projection can be separated into a linear and a nonlinear component,they accounted for 67.45% and 32.55% variance,respectively.In summer,the anomaly circulations over the Bay of Bengal,indo-china Peninsula and the west to Philippines Archipelago are induced by the nonlinear component.

Abstract:The relationships between different types of El Nino events and East Asian summer monsoon(EASM) as well as summer precipitation in China are discussed in detail.In the developing years of western and standing-wave/eastern patterns El Nino events,EASM is weaker/stronger than the normal.In the decaying years of western and standing-wave/eastern patterns,EASM is rather stronger/ normal.Moreover,in the developing years of western pattern El Nino events,the summer precipitation is less than the normal in North China,the upper and middle reaches of Yellow River,Dongting Lake and Poyang Lake valleys,and parts of South China,but it is relatively more in the Yangtze-Huaihe River Valley,and it is the reverse in the decaying years.In the developing years of standing-wave pattern,there are less rainfall in the Yangtze River Valley and the northern part of North China,and more one in South China and the middle part of North China.Rainfall in Sichuan basin and South China is less than the normal in the decaying years,meanwhile it is more in the Yangtze River Valley and the middle part of North China.Despite in the developing or decaying years of eastern pattern,the rainfall is less than the normal in most of China except for in Sichuan basin and Huanghe-Huaihe Valley in the developing year,and in parts of South China and North China in the decaying years.

Abstract:High-resolution satellite data are used to analyze the features of the onset process of the tropical Asian summer monsoon(TASM) from the point of the climatology view.It is found that the TASM onsets first over the western region of Indo-China Peninsula,next the whole area of Indo-China Peninsula and the eastern part of Bay of Bengal,and then all Bay of Bengal and South China Sea.However,the enhanced rainfall tendency in Indo-China Peninsula is not more obvious than that in Bay of Bengal and South China Sea after the summer monsoon onset.The 26th to 28th pentad(the first pentad to the fourth pentad of May) is the period of onset process of TASM,during which,the spatio-temporal evolution of low lever wind field corresponds well with convective precipitation,while the sea surface temperature warms one pentad ahead compared to the sea surface wind changing.Mean while,the precipitation of South China is mainly frontal precipitation,named the subtropical monsoon precipitation.The result also demonstrated that using convective precipitation and 10 meters wind field above the sea surface to represent the spatio-temporal evolution of rainfall and prevailing wind of summer monsoon respectively is more accurate and more precise than those routine data.

Abstract:Based on the observations at Lin’an regional background station in Zhejiang Province from December 2003 to November 2004,the seasonal and diurnal variations of NO_x and SO₂ concentrations are analyzed.Result shows that the winter background concentrations of acidic gases NO_x and SO₂in the Yangtze River Delta region are the highest with 23.81×10^-9and 37.3×10^-9(volume fraction),respectively,mainly affected by the relatively high concentration contamination transportation from the urban agglomeration of Shanghai-Nanjing area to the northeast of Lin’an.The concentrations of acidic gases are the lowest in summer,mainly contributed by the local emission sources.Rainfall can obviously scavenge SO₂,but it has low effect on NO_x.The diurnal variation of NO_x concentration presents a typical bimodal pattern with the higher value at 09:00 BST and the maximum at 18:00 BST in winter,while the variation is an unimodal pattern with the maximum at 07:00 BST in summer.The diurnal variation of SO₂ concentration is remarkable in winter and spring with the maximum around 06:00 BST and the minimum around 15:00 BST.The air quality of annual regional NO₂ conforms to the primary standard of GB 30952—1996(Ambient Air Quality Standard),but SO₂ concentration exceeds the allowable limit notably in winter and spring for the obvious influence of human activity.Air pollution indexes of NO₂ and SO₂ reach the maximums 50 and 93 in December,respectively.The weekend effect of NO₂ and SO₂ does not happen in this region.

Abstract:The cross-wavelet transform method is adopted to study the multi-time scale correlations between the winter temperature,the summer precipitation in Northwest China and the Arctic Oscillation Index(AOI) over the same period,in order to investigate the relationships between climate change in Northwest China,the AOI,and the Eurasian zonal circulation index in recent 56 years.Results show that there are multi-time scale periodic variations in AOI,the temperature and precipitation in Northwest China with significant syntonic periods of qausi-3 a between AOI and the precipitation,while the multi-time scale correlations between AOI and the temperature are quasi-2 a,3—5 a and about 8—11 a with the strongest coherency in 8—11 a syntonic period.The influence of AO on temperature is more remarkable than that on precipitation in Northwest China for the interaction of their interdecadal variation.When the AO is in positive phase in winter,the Eurasian zonal circulation is stronger,and the temperature is higher.The fact that variation of summer precipitation in Northwest China is close related to the prior abnormal AOI is an important factor for the prediction of summer precipitation.

Abstract:Based on the daily precipitation data of 130 stations selected over China from 1961 to 2004,the variance due to climatic noise and potential predictability of seasonal precipitation over China are estimated in terms of low frequency white noise extension method and the analysis of variance.Results show that the variance due to the climatic noise of seasonal precipitation decreases gradually from south to north and from the coastal to the inland.It varies with markedly seasonal variations,with the greatest in summer and the smallest in winter,and the seasonal variation is larger in the inland than that in the inshore.Although potential predictability of seasonal precipitation is different from season to season and from area to area,the seasonal precipitation of the most areas over China can be predicted.Regarding the absolute error which is smaller than 0.68 times of standard deviation as the criterion of correct prediction,the upper limit of the prediction accuracy would be 50% to 60% in a majority of China.

Abstract:While the ERA40 project by European Center for Medium-Range Weather Forecasts(ECMWF) provides ozone reanalysis data,in order to use the data more effectively and reasonably,a comparison analysis is done for the ERA40 and Halogen Occultation Experiment(HALOE) data.Ratios of noise relative to signal are estimated firstly by HALOE observational ozone concentration on seasonal and interannual timescales respectively.The results indicate that there are significant seasonal and interannual variations in a large part of stratosphere.The comparison analyses suggest that seasonal variation of ozone from ERA40 is similar to that from HALOE observations,whereas interannual variation of ozone from ERA40 is greatly weaker than that of HALOE observations in the tropical middle stratosphere,but is stronger at middle latitudes in the lower stratosphere.

Abstract:Based on the NCEP/NCAR reanalysis,British Meteorological Office global sea surface temperature(SST) and China 160 stations temperature data during 1951—2000,the empirical orthogonal function(EOF),composite analysis,correlation and singular value decomposition(SVD) methods are used to study the effect of the Indian Ocean Dipole(IOD) on South of China rainfall(in China south of 33°N).Results show that the SST anomaly in Indian Ocean aroses the atmospheric circulation anomaly,which induces the rainfall anomaly in South China.When Indian Ocean SST is higher(lower),South China rainfall is more(less) than the normal.When IOD is positive(negative),the precipitation is more(less) in South China and less(more) in the Yangtze River Basin.

Abstract:Based on the observed winter snowfall data of Weihai,Shandong Province and NCEP/NCAR reanalysis data during 1966—2005,this paper studies the spatial and temporal distributions of winter snowfall,and the climate background of persistence snowstorm event in Weihai City in December 2005.The results reveal that the winter snowfall is excessive in North and few in South Weihai City,and the snowfall and the day numbers of snowstorm in December are significantly more than those in other months.The climate background in December 2005 is closely similar to that in the more snowfall years of Weihai in December.In the more snowfall years,the meridional circulation lies in northeast Asia with obvious negative centers of 500 hPa height and 850 hPa temperature anomalies locating in Northeast China,Yellow Sea,and sea areas from Bohai Sea to Japan Sea,where there are cyclonic wind anomalies at 1 000 hPa.In the above mentioned areas,the element anomalies in December 2005 are much more robust than those in heavy snowfall years.Moreover,Yellow Sea and Bohai Sea in the last ten-day period of November 2005 is much warmer than the normal,which provides sufficient energy for the atmosphere and results in the instability of atmospheric boundary layer.The terrain uplifting in Shandong Peninsula and the convergence of land-sea breeze and environmental wind in the northern coast directly result in the unstable energy release and the continuous heavy snowfall in Weihai city.

Abstract:The Regional Climate Model version 3(RegCM3) is used to investigate the effect of black carbon(BC) aerosol on regional climate in China.The influences of BC aerosol on the radiative forcing,air temperature,and rainfall are analyzed.The simulation result shows that BC aerosol produces a positive radiative forcing at the atmosphere top,and a negative forcing at the surface in the region.Adding of BC aerosol causes distinct changes in surface air temperature in the continental area of China,and the changes show obvious seasonal characteristics.The surface temperature increases in most regions in January,whereas it increases in northern China and decreases in southern China in July,and it does not change significantly in April and October.The result also shows that BC aerosol emission leads to the increase of summer rainfall in the mid and lower reaches of Yangtze River,but results in rainfall reduction in some regions of northern China.

Abstract:In order to investigate the effect of the topography on the vortex self-organization in the rotational atmosphere,two numerical experiments,with 48 hours integral time are performed by using a β-plane quasi-geostrophic barotropic vorticity equation model with a topographic term.The main distinct differences between the rotational and non rotational atmosphere resulting from introducing the β term are as follows:Firstly,in the non rotational atmosphere,the characteristics of the multi-vortices self-organization are that the quasi-final vortex absorb or organize all of the initial multi-vortices;but those in the rotational atmosphere are absorbing or organizing the initial multi-vortices partly.Secondly,the influences of mesoscale topography on the quasi-final structure position are smaller in the non rotational atmosphere than that in the rotational atmosphere;the distance between the two quasi-final vortex centers in the rotational atmosphere is as twice as that in the non rotational one,the former is about 200 km but the latter about 100 km no matter introducing the topographic term.

Abstract:By using the ground-based and airborne measurements of raindrop size distributions(RSDs) during a precipitation process of stratiform cloud appearing on July 9,1982 in Yinchuan,Ningxia,the characteristics of the surface and upper RSDs are analyzed and compared.It is found that 61.9% surface RSDs exhibit the exponential distribution,whereas 86.4% upper RSDs show the multi-peak distribution.The mean surface and upper RSDs are more suitable to fit with a Gamma function.Result also reveals that the most raindrops near surface are smaller and the most raindrops at the upper are relatively bigger,which is possibly caused by the effects of coalescence,breakup and evaporation of raindrops.In addition,the correlations between the rainfall intensity(I) and the radar reflectivity(Z),the rainwater content(W) and the raindrops concentration(N) are established,respectively.There is a very good correlation between I and Z,and W,but N,parameter N₀ and parameter λ are poor correlated to I.

Abstract:By using the data observed in 17 February—2 March 2006,the turbulent characters of nondimensionalization wind velocity(u,v and w),and air temperature at the urban and suburban sites in Nanjing are analyzed and compared to the results of other sites observations.In addition,the applicability of M-O similarity theory is validated over urban and suburb.Results show:the standard deviation of dimensionless fluctuating wind velocity(u,v and w) varies with the 1/3 power of the stability with some differences over urban and suburban,the deviation in vertical is smaller than in horizontal,especially in non-neutral stratification.The normalized standard deviation of temperature increases with the stability decreasing,with some differences over urban and suburban underlying surface.Under unstable condition,the standard deviation of temperature varies with the-1/3 power of the stability over urban but 2/3 power over suburban,under stable conditions,the -1/3 power of the stability over urban can be found but no universal relationship over suburban.

Abstract:Based on the adjoint data assimilation model and the positive model of unstructured triangular meshes and finite volume method,a formula for inversing wind drag coefficient is developed.The wind drag coefficient is automatically calculated by the numerical iteration process of intra-region observations.A series of adjoint data assimilation numerical experiments of generalized estuary are carried out successfully,indicating that:1)the method is correct and effective;2) the enough observed data can improve the inversion precision;3)the wind velocities of 10 m/s or 15 m/s have little influence on the inversion result of wind drag coefficient.

Abstract:Based on the hierarchical prior method,we study the Bayesian local influence of the mixed-effects model for longitudinal data.Two types of perturbation schemes are proposed based on the characteristics of longitudinal data which include both individuals and individual cases.The Bayesian local influential method and formulas of parameter estimates are provided under these perturbation schemes.An example is given for illustration.

Abstract:Linear constrained constant modulus algorithm(LCCMA) and linear constrained differential constant modulus algorithm(LCDCMA) were studied in this paper.Using different signal amplitudes to simulate their convergence and stability,its results tally with the theory analysis.Simulation results show that the LCCMA can remove multiple-access interference completely if and only if the desired user’s amplitude is no less than the critical value 1/√3,however,the LCDCMA in all test situations can converge to desired user.It is superior to LCCMA in fast convergence and robustness.

Abstract:This paper proposes a mobile agent based composite service execution mechanism to achieve the process oriented composite service represented by BPEL4WS.This paper also gives a detailed process of execution of composite service.Mobile agent based composite service execution is a P2P(peer-to-peer) execution model which can avoid the performance bottleneck of center peer and effectively reduce the network load.Due to the cost of agent migration,this paper investigates and designs a mobile agent resident strategy to avoid unnecessary migration,which raises execution efficiency greatly and reduces the resource consumption.