SEASONAL CHANGES OF SOIL MOISTURE INDUCED BY INCREASED CO2 AS SIMULATED BY THE ATMOSPHERIC GENERAL CIRCULATION AND MIXED LAYER OCEAN MODEL          下载免费PDF全文

Zhao Zongci  M. E. Schlesinger 《Acta Meteorologica Sinica》1992,6(2):170-178

The atmospheric general circulation model coupled to the mixed layer ocean model has been used to simulate thechanges of the global soil moisture.Comparing the simulated results with observations,it is shown that the model is ca-pable of doing sensitive experiments about the carbon dioxide change.The 2×CO_2/1×CO_2 comparison shows that there are the obvious changes of the soil moisture in the global forfour seasons.There are the wet soil moisture in the lower latitudes of both hemispheres and dry soil moisture in the mid-dle latitudes of both hemispheres for four seasons.The dry soil moisture in summer and wet in other seasons are foundin the northern higher latitudes.The analyses of the physical feedbacks responsible for the CO_2-induced changes of soil moisture show that the bud-gets of the surface water and heat are the important factors.  相似文献   

THE ALTERNATE-SEASONAL CORRELATION OF LONG-RANGE WEATHER PROCESS          下载免费PDF全文

Lin Xuechun  Zhang Ruixue 《Acta Meteorologica Sinica》1992,6(4):462-469

In this paper,the correlation of meteorological elements at an interval of 5-7 months,i.e.,the alternate-seasonal correlation,is thoroughly analyzed.The results show that the alternate-seasonal correlation is an important phenomenon in the long-range weather process,and it has a significant latitude effect and seasonal variations.Furthermore,the relation between this phenomenon and SST in the North Pacific is discussed.  相似文献   

长江河口最大浑浊带研究   总被引：42，自引：1，他引：42  

沈焕庭  贺松林 《地理学报》1992,47(5):472-479

本文在以前一系列研究的基础上,把长江河口最大浑浊带视作一个系统,对它形成的环境背景、时空变化规律、泥沙来源、絮凝作用对悬沙落淤的影响、浮泥的特性与分布、悬沙的富集机制等进行了较系统的综合分析,并指出了需要深入研究的问题。  相似文献   

Chemical composition of saline and subsaline lakes of the northern Great Plains,western Canada   总被引：2，自引：0，他引：2  

William M. Last 《International Journal of Salt Lake Research》1992,1(2):47-76

The northern Great Plains of Canada stretch from the Precambrian Shield near Winnipeg, Manitoba, westward for ∼1,700 km to the Rocky Mountains foothills. This vast region of flat to gently rolling terrain contains a very large number of salt lakes. Major ion chemical data on ∼500 of them are available. Although the average brine (salinity, 37 ppt) is a Na⁺−SO₄ ²⁻ type of water, the lakes exhibit a wide range of salinities and ionic compositions. This diversity is confirmed by Q-mode cluster analysis; it identified thirteen major water chemistry types. Most ions display distinct trends, both spatially and with increasing salinity. All dissolved components increase with increasing salinity, but at different rates. The relative proportions of Ca²⁺ and HCO₃ ⁻+CO₃ ²⁻ ions show a strong decrease with increasing brine salinity, whereas SO₄ ²⁻ ions increase with increasing salinity. The ionic proportions of Na⁺, Mg²⁺, K⁺ and Cl⁻ exhibit no significant relationship with salinity. R-mode factor analysis of the lake water chemistry, combined with selected environmental parameters, identifies groundwater composition, climate, and the elevation of the lake within the drainage system as most important in controlling brine chemistry and salinity on a regional basis. Variability in source of ions, reaction processes and products are undoubtedly key factors in helping to explain brine chemistry of an individual basin or variation from a local perspective, but these factors are generally poorly understood and not quantified on a regional basis. Palliser Triangle Global Change Project Contribution Number 3.  相似文献   

A standard table for predicting equilibrium dissolved oxygen concentrations in Salt Lakes dominated by sodium chloride   总被引：3，自引：0，他引：3  

J. E. Sherwood  F. Stagnitti  M. J. Kokkinn  W. D. Williams 《International Journal of Salt Lake Research》1992,1(1):1-6

An equation of state was used to prepare a standard table for the solubility of oxygen in sodium chloride sobutions at temperatures between 0 and 35°C and for concentrations up to saturation (260 ppt). The uncertainty introduced by linear interpolation between DO values in the table is less than the experimental uncertainty of data which was used to generate the equation of state. Where pressures differ from 1 atm the DO value from the table can be corrected provided the equilibrium vapour pressure of the salt solution is known. Where this is not the case an approximate correction (±0.5 per cent) can be used provided atmospheric pressure is in the range 950 to 1030 mbar. Predictions made using the standard tables will provide near but probably low (<0.2 mg L⁻¹) estimates of DO in salt lakes where sodium chloride is the dominant electrolyte (>70 per cent by mass).  相似文献   

Zooplankton distribution and abundance in saline lakes of British Columbia,Canada   总被引：2，自引：0，他引：2  

U. Theodore Hammer  László Forró 《International Journal of Salt Lake Research》1992,1(1):65-80

Zooplankton in saline lakes of the Southern Interior Plateau of British Columbia were collected on three occasions: mid-May and early August, 1990, and in late July, 1991. Salinities ranged from 2.6 to 45.8 g L⁻¹. Of the 17 lakes examined, 13 were hyposaline (∼-20g L⁻¹), four, mesosaline (20–50 g L⁻¹) and none, hypersaline (>50 g L⁻¹). pH ranged from 8.7 (Three Mile) to 10.7 (Goodenough), with values <9.6 in 10, and <9.0 in only three lakes. Lakes with high pHs had high bicarbonate-carbonate alkalinities. Thirty one species of zooplankton occurred: Protista (1), Rotifera (13), Anostraca (2), Cladocera (7), Ostracoda (1) and Copepoda (7). Sixteen species were restricted to hyposaline waters, with seven found only in salinities of ≤5 gL⁻¹. Two species (Diaptomus connexus, Artemia franciscana) were restricted to mesosaline waters of salinity >35 g L⁻¹. Eurysaline species includedBrachionus plicatilis, Hexarthra fennica, Limnocythere staplini, Artemia franciscana andDiaptomus connexus. Most species were abundant in 1+ lakes, but six species always had low populations.B. plicatilis, Hexarthra polyodonta, A. franciscana, Limnocythere staplini, Daphnia similis andD. connexus had densest populations in one or more of the three most saline lakes, viz. Long, Goodenough and Three Mile. Cladocerans other thanD. similis (Alona sp., Ceriodaphnia quadrangula, Daphnia pulex) were usually abundant in lakes of low salinity (<5 g L⁻¹).Diatomus sicilis, present in all except the three most saline lakes, also occurred in abundance in ten of these lakes.Moina hutchinsoni andH. polyodonta were present in both hyposaline and mesosaline lakes, but, more importantly, tended to occur only at higher pH values (>pH 9.4) but not in all such lakes. These can be regarded as alkaline-saline species. Sorensen’s Coefficient of Community Similarity was used to compare communities in Alberta-Saskatchewan and British Columbia. It was low (0.37). A comparison restricted to just Cladocera gave a slightly higher value, 0.44, but a comparison of Copepoda gave a value of 71 per cent similarity between the regions. Multiple regression analyses using pH, TDS and K regressed on species richness for all samples accounted for only 41 per cent of the variance. However, when the analysis was seasonally restricted (May), and thus to a limited chemical range, 47 to 77.5 per cent of the variance was accounted for by these three variables.  相似文献   

Lake Balkhash,Kazakhstan   总被引：2，自引：0，他引：2  

T. Petr 《International Journal of Salt Lake Research》1992,1(1):21-46

Lake Balkhash is a large (18,000 km³), closed, and slightly saline lake in the south-west of Kazakhstan. It is divided into two basins, a south-western and an eastern basin. These have somewhat different limnological conditions, but the most obvious one is that the south-western basin has a salinity of <2 g L⁻¹ whereas the salinity of the eastern basin is ∼4 g L⁻¹. Numerous fish and invertebrate introductions, many successful, have been made. In 1969, a dam impounding the Kapchagay reservoir was constructed on the River Ili, the major river flowing into the lake. The impoundment of water in this reservoir caused a fall of some 1.5 m in the water-level of the lake. This fall, together with other events on the catchment, caused considerable damage to reedswamps in the lake, to the fishery and to conservation values. A number of suggestions has been made on how to prevent further damage. Some, particularly those involving a moratorium on further filling of Kapchagay reservoir and irrigation, have been implemented, at least in part. This has caused some remission in environmental damage and provides for cautious optimism with regard to the lake’s future. Even so, the environmental status of the lake remains vulnerable and many dangers persist.  相似文献   

使用多时刻资料的北半球动力统计正压谱模式     

房春花  王得民 《南京气象学院学报》1991,14(4):586-591

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北半球环流异常持续性随运动尺度的分布     

张邦林  刘洁 《高原气象》1991,10(3):248-257

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THE EFFECTS OF SEA SURFACE TEMPERATURE ANOMALIES OVER THE MID-LATITUDE WESTERN PACIFIC ON THE ASIAN SUMMER MONSOON     

Ni Yunqi  Qian Yongfu 《Acta Meteorologica Sinica》1991,5(1):28-39

By Using the P-σ five-layer primitive equation model,three sets of numerical experiments are performedwith normal zonal mean SST(the control case),the positive SST anomalies in the Kuroshio current andeast-of-Japan Ocean(the midlatitude western Pacific),and positive SST anomalies over both the midlatitudeand the equatorial western Pacific.The experimental results show that the positive SST anomalies over themidlatitude western Pacific have great influence on the Asian summer monsoon:the Indian monsoon is weak-ened and the East Asian monsoon is intensified.This happens just reverse to the effects of positive SSTanomalies over the equatorial westero Pacific on the Asian summer monsoon.Further,the influence mechanismof the SST anomalies over the midlatitude westcrn Pacific on the Asian summer monsoon is discussed.  相似文献