Abstract:By using a global spectral model of quasi-geostrophic barotropic vorticity equation including diabatic heating,a series of numerical experiments of multi-refraction of atmospheric waves on perfect basic flows are run.The 16 perfect basic flows and 4 heat sources of tropical SSTA are considered and 30 days are taken for model integration. Results show that: (1) Disturbance excited by the heat source usually can have two or three branches of the wave trains, and the second or the third branch of the wave trains bifurcate from the first branch, or the third branch wave train bifurcates from the second.(2) For some basic flows, the first branch wave train disappears after maintaining two weeks or longer, and the other wave trains propagate still.(3) The second branch of wave train is the strongest in most cases and two branches of wave trains have the tendency of confluencing and focusing.

Abstract:Observational analysis is conducted of the effects of winter Pacific SSTA on the storm track and jet stream.It is shown that the positive Kuroshio (equatorial central and eastern Pacific) SSTA in winter can give rise to northward (east-and south-ward) movement of both the storm track and jet stream, and lead to substantial enhancement in the entrance aera of the storm track (central and eastern Pacific), but leave the center of jet stream little variation in intensity.As such, the jet stream varies in position and intensity mainly as a result of the change of temperature gradient in the tropics and subtropics,while the variation of the storm track in position and intensity is not only related to the jet stream,but also to the intensified baroclinicity which is mainly caused by diabatic heating.

Abstract:Introduced are the design thoughts,methods and functions of the system “Nanjing Atmospheric Science Information Center” on the Internet,which is based on Web and database technique.

Abstract:In the content of multiple planting experimental data, a dynamic model for HSTP rice is developed, including leaf area development, photosynthesis,respiration, dry matter accumulation and allocation sub-models. Much investigation is made on the relationship between I LA and temperature, simplified calculation for photosynthesis, estimation of net assimilation and variation of dry matter allocation coefficient with phenological stage.In comparison with traditional manual-transplanting (MT) rice, the reason why HSTT rice could reach high yield is revealed in combination with meteorological influence.

Abstract:A non-linear stochastic-dynamic model with threshold is applied to do forecast experiment for the rainfall in Changjiang-Huaihe Reaches. Results show that the model can accurately forecast the precipitation caused by large scale circulation. The comparasion of forecast accuracy between air-sea coupling model and external forcing model is also made,indicating that the former is a little better than the latter.

Abstract:In the context of the TOMS data,investigated are atmospherical total ozone secular trends (1979～1992),interannual changes as well as seasonal and periodic variations over Arctic and Antarctic. Results indicate that total ozone decreases persistently and has a turning point during its decline over northern and southern polar regions in recent decades.However,total ozone over the two polar regions has different secular trends and geographical distributions.The ozone declines most rapidly during spring over both polar regions,but fluctuates in different periods with stronger oscillation over Antarctic than over Arctic.In addition, the relation between atmospheric ozone variation and temperature is discussed,indicating that the former has important influence on the latter.

Abstract:Based on the ECMWF snow depth(1979～1993),winter SLP,500hPa height and China winter temperature data,the relationships between Eurasian winter snow cover anomaly and East Asian winter monsoon (EAWM),China winter temperature are studied in terms of correlation and composite analysis.Evident relationships are found between the Eurasian winter snow cover anomaly in mid/high latitudes and EAWM,Chinese winter temperature.

Abstract:Similar to the method of Z-index of precipitation,a trial research is made on monitoring drought by the amount of cloud,and the method of Z-index of cloud amount is established.Based the five day mean total cloud amounts and high cloud amounts, from 1987 to 1992, the Z-index of cloud amount on the different time intervals of 1992 is calculated and showed by graphs, and compared with Z-index of precipitation at the same time. It is shown that the method of Z-index cloud amount is effective.Since the cloud amount can be obtained directly from satellite cloud pictures,the difficulty and limitation of getting the data of precipitation with conventional observations can be avoided.This method can be used to monitor drought in regions being short of the precipitation data, such as the west of China.

Abstract:This paper analyzes the impact of rising sea level in the future on sea dikes,shipping and coast zone water resource in the Yangtze Delta and presents proposals for corresponding countermeasures.

Abstract:By means of wavelet analysis and moving correlation, the multi-time scale variation characteristics of Chongqing summer rainfall and equatorial eastern Pacific winter SST are discovered.The correlation between rainfall and SST is significantly different in different time scale,thereby showing a multi-time scale features.

Abstract:The singular cross-spectrum analysis(SCSA) is used to extract the coupled-oscillation signals between SST over Nino oceanic regions and SOI,therefrom describing their interannual and decadal variation features.The short-term climatic prediction experiment is made for SST over Nino oceanic regions based on reconstructed coupled oscillation components series(RCCS) together with regression model. Results show that there is different coupled oscillation periods between SST over different Nino oceanic regions and SOI,as well as different interannual and decadal variation features,thereby forming ENSO’s complexity in its space/time evolution. The forecast skill of SCSA combing regression model is mostly superior to the SSA-AR prediction model,demonstrating its advantages in actual prediction experiment.

Abstract:Based on former researches,analysis was performed of various climate scenarios’ impact on wheat growth and yield formation with enhanced Ultra-Violet radiation taken into account. Further work has been done using numerical simulation and results show that higher CO₂, and air temperature,changing precipitation and enhanced UV would cause decreased wheat yield.

Abstract:This paper demonstrates the constructing algorithms and the design of pipeline of image preprocesser based on discrete linescan method which is widely used,and provides the example of application.

Abstract:A leaf age model of rice is statistically established in context of field experimental data according to its biological properties and environmental responses. Results show that day length is the first factor affecting the leaf age and temperature the second.

Abstract:By using the monthly mean temperature data from surface up to 30hPa in 1958~1995 over Lhasa and Nanjing,investigated are several climatic features and vertical distribution characteristic of monthly,seasonal and annual temperature variability over Lhasa with the conditions over Nanjing compared.The relationship is also discused between the climatic change at low stratosphere and middle troposphere over the two stations on one hand,and total ozone at high latitudes over Eurasian continent and the south Asia high on the other hand.

Abstract:Analysis is performed on the features of climatic productivity and the impacts of climate change air temperature and rainfall on agricultural production mainly wheat and rice in the past 50 years in Kunming.Results show that precipitation during Dec. to next Feb. is critical to wheat growth and accumulated temperature of ≥10℃ plays a more important role than rainfall for rice production.The time period when weather disasters restricting agricultural production of Yunnan Province happened is diagnosed with the aid of calculated annual dry and warm indices and it is indicated that the major weather for crops sown in late autumn are drought during Jan. to Feb. and cold from Feb. to April, and for those sown in late spring are drought in May and cold from July to August.

Abstract:Based on 3 kinds of observation datasets,chaotic characteristics of atmospheric turbulence over four different surfaces are analysed.By investigating four characteristic quantities describing chaos: power spectrum, correlation dimension, Lyapunov exponents and correlation entropy, separately, some meaningful results have been derived. Although the underlying terrains are very different,their atmospheric turbulences are all of chaotic motions.

Abstract:The monthly precipitation and temperature data of 160 stations in China during 1951～1998 are used to analyze the basic properties of the precipitation anomalies in the middle lower reaches of the Yangtze River with focus on their relationships with the precipitation and temperature anomalies in China.Results indicate that there are remarkable seasonal,interannaual and interdecadal variations of the precipitation anomalies in the middle lower reaches of the Yangtze River,with the magnitude and frequency anomalies occurring in Jun. to Jul.,especially in Jul..In the recent 48 years,there are three obvious climate periods of the precipitation anomalies in the middle-lower reaches of the Yangtze River,ten flood years and eight drought years can be selected.The EOF analyses of the composite precipitation anomalies in flood and drought years in the middle-lower reaches of the Yangtze River show that spatial and temporal distribution properties of precipitation anomalies in China are different in drought and flood years;the different characteristics of temperature anomalies in drought and flood years in China in the prior and following month are also studied.

Abstract:One-point correlation analysis is undertaken for 500hPa geopotential height field in early summer for 1951～1998,with focus on the relationship between teleconnection patterns and China early summer rainfall in 1991~1998.Results show that exceptional flood in 1991,1996,1998 and severe drought in 1997 bear connection with the anomaly of the east Asia pacipic(EAP) pattern and the Huanghe river east Asia(HEA) pattern with the exception of 1992,and that the flood in 1998 over northeast China is also linked to the anomous powerful west Asia(WA) pattern.

Abstract:Based on the meterological observation data in the Yangtze Delta in 1951~1995, this paper analyzes the climate change of meteorological clements such as mean air temperature and precipitation, maximum and minimum air temperature, major meteorological disasters. Results show that there are obviously a warming trend in winter,a cooling trend in summer, an increasing in the variability of mean air temperature and precipitation,and a rising in meteorological disaster frequency.

Abstract:The theory of slantwise vorticity development is used to diagnose a severe winter rainfall and snowfall process over Yunnan.Results show that the very stiff moist isentropes can lead to the development of moist slantwise vorticity and the severe precipitation may occur there;conditionally symmetric instability is another important factor responsible for this severe precipitation;the weak atmospheric stability and strong baroclinicity are favourable to the happening of severe winter precipitation over Yunnan.

Abstract:Through the dynamical analysis on the sudden calamitous weather,it shows that:the sudden calamitous weather has the feature of quickly excitative rapid process and relatively stable development slow process;the excitative process of the sudden calamitous weather is the non conservative process of wet potential vorticity resulted from the dynamic non-equilibrium of various factors affecting potential vorticity in the condition of wet potential vorticity tending to zero, and it is the excitation process of the geostrophic departure in middle latitudes;the happening time of the sudden calamitous weather is often corresponding to the time of the turning change of one of the factors affecting potential vorticity, while the happening area is the area where the wet potential vorticity tends to zero.

Abstract:Relations of maturity to one-hundred-grain weight and to grain moisture as well were investigated on the basis of thermal indexes for various maize varieties.Additionally,analysis was performed of the maturity and its probability for the varieties from place to place,offering a scientific base for reasonable variety arrangement.

Abstract:The lifespan of MCC over China mainland is divided into 7 stages with the features of its energy evolution process discussed in detail.Results show that there exists a deep instable layer below 500hPa during the whole MCC lifespan with the instability decreasing generally and that the moisture and heat flow into MCC from its southwest and south side with the maximum flux being at 900~500hPa.It is also found that the low level jet accompanied with upper-level jet and mid low-level trough is favourable to the formation and development of MCC.

Abstract:A non-inferior solution is presented to the CMCM-1998A with its explanation in n dimentional real space.For cases that n equals to 1,2,3,the geometrical explanation is given.

Abstract:Features of meteorological data and serial flash memory are analyzed,and the application of serial flash memory to the meteorological data collecting is discussed.On this basis an experimental example of meteorological data collecting is also given.

Abstract:The generation of far side-lobe echoes for offset parabolic antenna is analysed in this article,and the experiments have proved the existence of far side-lobe echoes.It is concluded that an offset feed parabolic antenna has the advantage in side-lobe suppression over central feed parabolic antenna.An offset antenna won’t generate far side lobe echoes when scanning in low elevation angles,but when the angles turn high,it will.In the application of Doppler radar,controlling the rotation speed of antenna is helpful in eliminating the effect of far side-lobes.