Abstract:The adjoint model technique is employed for the meteorological data assimilation of mesoscale models.It is a variational method whose constraints are represented by the dynamic model for numerical weather prediction, and is a substantial improvement on the traditional variational scheme.Documented in this part is the layout of the adjoint model system with particular reference to the structure. And the model is derived in terms of a conjugate code method. Experimental evidence so far obtained suggests that the adjoint model has quite high assimilation ability.

Abstract:On the basis of the companion paper Part Ⅰ:Layout of an Adjoint Model, study is undertaken of the verification of the adjoint model code, indicating that the conjugate code method is effective enough that the derived adjoint model is compatible with the theoretical conjugate equation. Experimental evidence shows that the assimilation scheme is able to remove stochastic interference, yielding good results. The assimilation is such that the study system deals with the assimilation of large scale information and thereafter of meso-and small-scale message.

Abstract:An optimal model was presented for rice developing rate by means of generalizing concerned research findings. The model, involving the integral impact of temperature and day-length on rice developing rate, was tested and gave good predictions. The growing period was outputted from the model for early,middle-and late-season rice respectively for 165 stations throughout the country with temperature data collected from 1951 to 1980. The relative mean deviation from the averaged growth duration over the time and then the stations was indicated for each station on a regional map, from which temporal and regional variations of the growing period were ecologically explained.

Abstract:In the context of the ECMWF daily analysis and NCAR reanalysed data investigation is undertaken of the ENSO effect on the Pacific storm track during winter. It is shown that mean baroclinicity shows a great increase (decrease) over the Pacific storm track area during El Nino (La Nina) year, which makes the track strengthen (weaken) along with stretching eastwards (withdrawing westwards) and vigor (faint) low-level up-and pole-ward transport of transient edd heat fluxes there, suggesting that the ENSO event plays a crucial role in the maintenance and development of the Pacific storm track.

Abstract:The formation and variation in intensity of summer monsoon is one most important aspect of monsoon problems. Investigation is undertaken on the East Asian monsoon indices in the context of 1951～1992 sea level pressure (SLP) and Pacific sea surface temperature (SST) data, trying to discuss the relationship between summer monsoon and ENSO. It is shown that the East Asian summer monsoon is weaker in the mature year of El Nino as composed to that of La Nina, but V.V. for their next year.

Abstract:The rain gush associated with the Jiang-Huai Mei-yu front occurred on July 9,1991, was observed with the Doppler radar in Nanjing Institute of Meteorology. The analysis of the data has shown in this paper that the rain gush was closely related with the activity of the mesoscale vortex system in the boundary layer. The vertical structure features of air flow in the lower atmosphere in the region are also revealed.

Abstract:The East Asian summer and winter monsoon intensity indices are constructed by using the SLP data for the period of 1873～1996/1997 and their interannual and inter decadal variabilities are analyzed. The results show that summer and winter weather/climate over China are closely related to the monsoon intensity indices and The East Asian summer monsoon intensity has a positive relationship with the Indian monsoon, and their intensities manifest quasi-biennial oscillations.

Abstract:The physical mechanism of interaction of binary typhoons with the same intensity is investigated in terms of a nondivergent barotropic model with no basic flow.The typhoon A is situated to the west of typhoon B. The two typhoons are 600 km apart, and have the same intensity. In the asymmetric flow field of typhoon A(typhoon B),the azimuthal phase of asymmetric gyres due to the linear beta effect is opposite to (the same with) that of asymmetric gyres due to typhoon B (typhoon A). Therefore, the large scale asymmetric gyres of typhoon A(typhoon B) is weaker (stronger). The counterclockwise rotation of the small scale gyres leads to typhoon A to loop counterclockwise. The steady southerly asymmetric flow causes typhoon B to move toward the north.

Abstract:A methodology is presented for the real time, automated identification,structure analysis, tracking and short range forecasting of storms with Doppler weather radar volume scan data. A “storm” is defined as a continuous region where the specified thresholds for both volumetric size and radar reflectivity are exceeded. The “centroid tracking” technique is employed to match the storms at one time with those at the following, and mergence and division have been taken into account. Based on the least square analysis on the time series of the central position and size of a storm, its new position and size within a short period can be predicted with linear extrapolation. The result shows that this method can be a useful tool for the identification, tracking and warning of severe convective weather.

Abstract:A climate scenario of temperature and rainfall under doubled CO₂ was derived from synthetic studics of home and abroad for Jiangsu Province.Based on the scenario,effects on winter wheat production were studied of increased CO₂ and enhanced solar UV radiation and the crop climate productivity were estimated under two hypotheses of invariable and variable crop growing period respectively.Results showed that wheat output would rise in most part of the province to north of the Yangtze River and go down either in part of southern valley between the Huaihe River and the Yangtze River or in the south of the province.Furthermore,wheat growing was climatically regionalized over the province by fuzzy classification method and finally a number of suggestions were put forward for adjustment of planting system and development of agricultural production.

Abstract:The operational system of crop yield forecast service(OSCYES)is one of subsystems of microcomputer operational system of agrometeorological surveillence and forccast servicc (MOSASFS) for zhejiang province. This subsystem consists of data processing crop yield analysis, development of crop yield model and realtime prediction and is highly automatic and easy to operate. It reached good results through a trial for 1994 to 1996.

Abstract:A new technique named continuous dynamic grid adaption (CDGA) technique is introduced in this paper.In order to improve the accuracy of numerical solutions by making arbitrarily local grid close together and to avoid great increase of computational expense. Considering variable principle, the resulting mesh from CDGA technique has advantages of smoothness, orthogonality and the adjustmentability in cell volumes. Using the MM4 with CDGA technique, the simulation results of the heavy torrential rain event on June 14,1992, show that the modified model runs steadily, and the 24 hours rainfall forecast is evidently improved.

Abstract:In this paper,turbulent flux over canopy of field crops was calculated using Profile Gradient Method derived from Monin Obhov Similarity Theory and drag coefficient,Stanton number and Dalton number were also further defined.The applicability of universal function which was used for turbulent flux calculation was examined and whether or not the flux and drag coefficient varied with atmospheric stratification stability,roughness length and average wind speed was discussed.Results of the study indicate that the flux depends on the stability and the drag coefficient,the Stanton number or the Dolton number is pertain to the stability,roughness length and average wind speed respectively.

Abstract:A radiation fog which occurred for five successive days was observed with an Atmospheric Data Acquisition system, Vertical profiles of temperature, moisture and wind fields were obtained during formation and dissipation of the radiation fog. Based on these data, boundary layer features at different stages of the fog development are discussed in the article. Results suggest that temperature inversion plays an important role in the formation and growth of fog, while fog has also important effects on temperature, moisture and wind structures in the atmospheric boundary layer.

Abstract:By using the data of latitude of Antarctic sea ice (1973～1989) as well as cyclone numbers (1972～1981) over the Southern Hemisphere, the influence of the changes of Antartctic sea ice on the pre flood season rainfall in Southern China has been analyzed. The results show that the pre flood season rainfall in southern China will increase with the Antarctic sea ice area, and vice versa. The north demarcation line of the sea ice facing Wilkes Land from February to March has close relation with the pre flood season rainfall in southern China. The stretch and withdrawal of the north demarcation line of Antarctic sea ice near the Ross Sea (180°) are indicative of the pre flood season rainfall in Southern China. The cyclone activity over the low latitude region of the southern Hemisphere acts a link between Antarctic sea ice and the pre flood season rainfall in Southern China.

Abstract:Through analysis of soil water and phenological data of four successive years, regular pattern of winter wheat evapotranspiration was analyzed for the area of Xifeng, Gansu Province and the critical period of water requirement was determined during which water plays the most important role in the development and yield formation of the crop. A notion, water consumption characteristic coefficient, was presented and used for evaluating the status of water supply and demand in various developmental stages. Results showed that lower yield might be caused by a smaller coefficient during the period from elongation to ripening. Therefore booting water is needed for reduction of sterile spikelet and grout filling water for increase of grain weight.

Abstract:The relationship of the rainfall rate averaged over a sampling area, which is sufficiently large and conditionally homogeneous of climate, with the cloud coverage, standard deviation of the brightness temperatures at cloud top,and temporal variability of the cloud coverage, has been studied, and three statistical models are obtained for estimating rain amount with digitized, 1 h interval infrared images from geostationary satellite. The results from the precipitating weather on the 5th, 6th and 10th of July in 1991 show that the models are quite good at the estimation of daily precipitation. Because cloud isolation and tracking to examine the life stage are not necessary, the models are easy for applications and can be used in other areas as well provided the sampling time and meteorological conditions are similar.

Abstract:This paper uses the historical research of meteorology to solve the contentious problem of two chinese terms(亚热带、副热带) correspending to “subtropical zone”. Many specialists tend to reject one of these two terms for simplicity. This paper introduces five systerms of climatic zone; studies how these two terms come from the systems of climatic zone historically; details the different origins and meanings of these two terms; and points out that though these two terms are translated from the same words, rataining these two terms have the superiority from the using of original polymeaning words,“subtropical zone”.For Scientific nomenclature, one prefers moronceening words rather then polymeaning words for expressing explicity.