Abstract:Composite analysis and singular value decomposition (SVD) are used to investigate the relationship of summer rainfall patterns in east China to the circulation and SST fields in the synchronous and previous (winter) seasons in the context of 1951～1995 northern summer montyly mean 500 hPa height and north Pacific SST. Results show that the rainfall patterns bear a close relation to the circulation and SST characteristics; the rainfall distribution is associated both to the synochronous circulation configuration, especially in Eurasian westerlies and noticeably to the previous counterpart; pronounced difference is found between the three rainfall patterns, each corresponding to the previous SST, greatly differing in characteritics.

Abstract:In the context of 1985～1988 ERBE data and 1984～1988 ISCCP satellite albedo and total cloudiness in connection with Qinghai-Xizang actinometric measurements, investigation is performed of the climatic retrieval of surface absorbed shortwave radiation (SASWR) in the research highland. Evidence suggests that the method gives higher fitting accuracy with mean error of 9.8 W·m^-2, whereupon calculated is the monthly mean SASWR flux density at the gridpoints of 2.5°×2.5° resolution over 25 °N～40 °N, 75 °E～95°E and 63 stations alongside the distribution prepared for its basic features.

Abstract:Summer monsoon index defined by land-sea presure contrast is compared to that by south-Asian monsoon circulation in characterizing the interannual variation of floods/droughts over the mid-lower valleys of the Yangtze. In terms of principal tropical circulation of east Asian monsoon defined is the summer monsoon index that is found to reflect well the interannual variation in the flood/droughts. The study shows that the difference in both higher and low index and the interannual variation has higher ability to identify the pattern of atmospheric circulation related to east Asian summer rainfall through the use of the index compositing and SVD analysis of northern 500 hPa height and synchronous SSTA at tropics in the context of 1982～1994 mean precipitation (precipitable water) and the 500 hPa height anomalies.

Abstract:In the context of wavelet technique and coherence analysis the existence of east Asian monsoon QBO is investigated together with its relation to ENSO variability. Results suggest that the monsoon exhibits noticeable QBO but the periods and amplitudes show significant change on an interdecadal basis with the QBO evolution in close relation to an El ñio episode; the western Pacific warm pool serves as a key area connecting the monsoon and ENSO cycle in such a way that the strong QBO winter monsoon first gives rise to a teleconnection wavetrain, followed by anomaly occuring in the warm pool that is then moving eastward, exerting effect on equatorial eastern Pacific SST, causing El ñio happening; the monsoon QBO is responsible for strong seasonal ENSO phase-locking and for its warm phase lasting one year or so.

Abstract:The T₄₂L₉ GCM is adopted to investigate in detail the effect of equatorial west Pacific (EWP) SSTA on the Pacific storm track during winter. Results show that the warm SSTA is responsible for appreciably intensifying the synoptic-scale perturbation vigor in the track region-and the track development-associated eddy heat/momentum fluxes get enhanced at the track entrance region as well, thus revealing a crucial role of low-latitude external heat forcing in the maintenance and development of the track.

Abstract:This paper presents some properties of the SWEEP operator in the scope of least square regression subject to linear constraints and matrix of sum of squares and cross product (SS&CP) in singular ill conditions. Despite alternative approaches available, the SWEEP algorithm represents one of the most flexible tools due to its simplicity in calculation and statiistical implication of the matrix elements involved and, still more importantly, the output interpretation keeps full consistency with the explanation of general output.

Abstract:Artificial neural network (ANN) technique is applied to make forecasting of summer rainfall patterns for east China in the following way: i) predictors are searched in the previous datases following the relation of the pattern to the circulation and SST features of the preceding winter; ii) ANN prediction is constructed for the pattern in terms of the anterior 40 year data as a training sample for the ANN to learn according to specified rules, thereby arriving at a forecasting model of a categorized pattern. Also, attempt was made to predict such patterns in 1992～1996, with the results rather close to the observed.

Abstract:Diagnosis has been performed of the 1976/1977 and 1982/1983 El Niño events on the basis of NMC objective analyses. Evidence shows that in the prior period to the 1976/1977 occurrence, a weak winter monsoon dominated in east Asia in contrast to a strong monsoon for the 1982/1983 event; the intensity was responsible for the distribution and vigor of paired vortices around the equatorial western Pacific and hence of equatorial Pacific westerly anomalies. Moreover, anomalies of SST, OLR and velocity potential differ greatly between the events. In the light of our study, the 1976/1977 (1982/1983) El Niño is categorized as a weak eastern (robust western) event.

Abstract:POP (Principal Oscillation Pattern) study is undertaken of global tropical SSTA, obtaining propagating and standing eigenmodes, which, when combined differently, are related to the occurrence of El Niño/La Nina. It is suggested that their quasi-4- and quasi-2-year periods are salient and found that oscillations close in-period are marked by different patterns. Also, results show that four Niño regions in the tropical Indian/Pacific Ocean exhibit SSTA of the same phase, mainly in the middle of the oceans, with the Pacific peak time slightly ahead; it is much the same in the Atlantic except its somewhat weaker SSTA with the peak time lagged as compared to the counterpart of the Pacific/Indian ocean; it is suggestive that the explanation, simulation and prediction of El Niño/La Nina evolution in space/time should not be based on a single eigenmode but on their interaction, with emphasis on the fact that superimposition and phase-locking are important factors of the event cycle. Finally, the authors indicate that the local oscillations are worthy of consideration too.

Abstract:Based on NMC 200 hPa and 850 hPa wind, a study is undertaken of the relation of northern teleconnection to east Asian monsoon circulation anomaly in summer. Evidence suggests that when northern snow-forced teleconnection is generated in this season, anomalous zonal/meridional circulations are revealed in east Asia-western Pacific band; with east Asia-Pacific teleconnection formed, anomalous zonal circulation is dominant over that band; the anomalous vortex of north Pacific origin moves southwestward and, reaching the eastern Philippines, turns southeastward to continue its journey.

Abstract:The paper introduces an inteligence barometer based on an integrated silicon pressure sensor that has a bigger temperature coefficient and nonlinear error with a scheme proposed of interpolation done twice in a piecewise way to reduce temperature error to innegligible extent, thereby improving pressure reading accuracy. Besides, developed is a circuit for a simple watch counter to raise the reliability with a rational circuit designed to decrease watt consumption and a set of practical methods presented to improve the performances.

Abstract:Used was an one-way nested grid model consisting of a five-layer primitive equation model containing topography (Qian) and a limited-area fine mesh model over complex terrian to investigate the effect on east-Asian summer climate of the vegetation over the Tibetan plateau and its surroundings. The nested model was carried out in such a way that height and temperature fields at a range of characteristic surfaces from 5 day integration from the former submodel as initial fields were offered to the latter as boundary values at a 24 h interval. Also, the air-earth model was based on coupling by a surface heat balance equation revised by the vegetation parameterization (Deardorff). On this basis, numerical experiments were conducted for the cases of vegetation available (Exp. I) and none of it (Exp. II) in summer. Evidence suggests that coherence coefficients between the simulated and observed height and temperature fields were higher in Exp. I, and some increase was found in sea surface level pressure, low-level (850 hPa) height, latent heat transfer, humidity throughout the atmospheric extent and precipitation from Exp. I compared to the case of Exp. II in contrast to the temperature and thermal low intensity in the former case.

Abstract:Based on field experimental results and systematic ecology, a coupling model is designed to simulate the temperature of the canopy-water layer of a rice field. With different input into the model investigation is made of cold irrigation effect on the crop population structures and irrigative schemes, thus providing theoretical basis for the management of such rice growth.

Abstract:An developed mesoscale numerical model of soil-plant-atmosphere continum is used to simulate the characteristics of the planetary boundary layer (PBL) under desert-oasis interaction. Differences are found between them in the PBL depth, wind spiral, profiles of wind, potential temperature and specific humidity, and those in the oasis effect on the air over the desert up- and down- stream are examined, reproducing roughly daytime temperature conversion over oasis and atmospheric humidity conversion over desert next to it. The simulation presents close similarity to observation, leading to further understanding of the PBL structure over a complicated underlying surface.

Abstract:Following Davidon′s criterion of optimal iterative correction,a three-step quasi Newton method of nocorrection matrix stored is constructed for unconst rained optimization problems and applied to the solution of a large-scale complicated system of linearill-conditioned equations.Numerical studies show that the method is simple in calculation,quick for convergence and robustinill-condition resistance so good as to compare to a recursional gorithm and even for well-conditioned equations it is fast in computation,and small in storage size.It is thereby possible to further improve the application of non-conventional data in objective analysis and quality of medium-and small-scale wether system analysis.

Abstract:Based on observations of a corn field and an uncropped plot in Jingyang county, Shaanxi, study has been done of root water uptake and water supply-consumption pattern in the crop growth season, whereby proposed is a concept of a critical water period during its development and yield formation, into which a characteristic consumption coefficient is introduced, whereby objectively and quantitatively revealed is the consumption-related physiological-ecological character of summer-sowed corn.

Abstract:The relation between previous Pacific SST and summer rainfall in China is investigated through the agency of canonical correlation analysis (CCA). Evidence suggests that the first canonical pattern of the SST predictor has its seasonal distribution as follows: the SE part is higher in values than the NW in autumn, the east and west are lower than the central part in winter, the NW higher than the SE in spring and summer, and temporal variation of the canonical principal component pattern clearly reflects the El Nino episode. Also, the CCA-predicted summer precipitation experiments show that the rainfall response to the SST varies considerably from place to place and the forecast skill depends strongly upon the amount of correlativity between the rainfall index and canonical principal component.

Abstract:The S²MP structure is compared to two types of multi-machine structure, indicating the merits of the former. The achievement of the servicer is described and the S²MP behaviors in the respect of expansibility and programibility are objectively investigated alongside their realization.

Abstract:Through sequential sampling and Radok′s climatic persistence change testing in connection with EOF analysis, revealed are the main features of 1951～1992 persistence change in rainfall and temperature over the Jianghuai valleys of China, followed by adopting a sliding method and augmenting the number of small samples so as to find the time interval of the change and those at different levels, the latter indicating a range of time scales of climatic variation, with the inclusion of its sudden change on an interdecadal basis.

Abstract:Exploration is undertaken of the pairing of climatically statistical Z-I probabilities and Z-I relation based on April June statistics over 200 km around Changsha. Evidence suggests that the rainfall pattern is broadly similar in the wet season and the obtained Z-I relation is applicable to the study region; the relationship, when used with the ATi method, is able to further improve the measurement accuracy from a single radar set. Also, the technique is independent of a automatic surface rainfall measuring network.