检索结果-南通市图书馆

Evaluating the Capabilities of Soil Enthalpy, Soil Moisture and Soil Temperature in Predicting Seasonal Precipitation

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2018年第4期35卷 445-456页

作者： Changyu ZHAO Haishan CHEN Shanlei SUN Key Laboratory of Meteorological Disaster Ministry of Education (KLME)/International Joint Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)Nanjing University of Information Science and Technology (NUIST) School of Atmospheric Science Nanjing University of Information Science and Technology (NUIST)

Soil enthalpy （H） contains the combined effects of both soil moisture （w） and soil temperature （T） in the land surface hydrothermal process. In this study, the sensitivities of H to w and T are investigated using the multi-linear regression method. Results indicate that T generally makes positive contributions to H, while w exhibits different （positive or negative） impacts due to soil ice effects. For example, w negatively contributes to H if soil contains more ice; however, after soil ice melts, w exerts positive contributions. In particular, due to lower w interannual variabilities in the deep soil layer （i.e., the fifth layer）, H is more sensitive to T than to w. Moreover, to compare the potential capabilities of H, w and T in precipitation （P） prediction, the Huanghe-Huaihe Basin （HHB） and Southeast China （SEC）, with similar sensitivities of H to w and T, are selected. Analyses show that, despite similar spatial distributions of H-P and T-P correlation coefficients, the former values are always higher than the latter ones. Furthermore, H provides the most effective signals for P prediction over HHB and SEC, i.e., a significant leading correlation between May H and early summer （June） P. In summary, H, which integrates the effects of T and w as an independent variable, has greater capabilities in monitoring land surface heating and improving seasonal P prediction relative to individual land surface factors （e.g., T and w）.

关键词： seasonal precipitation prediction land surface process soil enthalpy soil moisture soil temperature

A Study of the Atmospheric Boundary Layer Structure During a Clear Day in the Arid Region of Northwest China

在线全文

学校读者我要写书评

暂无评论

Acta meteorologica Sinica 2009年第3期23卷 327-337页

作者：张强王胜 Key Laboratory of Arid Climatic Change and Disaster Reduction of Gansu Province Key Open Laboratory of Climate Change and Disaster Reduction of China Meteorological Administration Institute of Arid Meteorology China Meteorological Adminstration

The local climate and atmospheric circulation pattern exert a clear influence on the atmospheric boundary layer （ABL） formation and development in Northwest China. In this paper, we use field observational data to analyze the distribution and characteristics of the ABL in the extremely arid desert in Dunhuang, Northwest China. These data show that the daytime convective boundary layer and night time stable boundary layer in this area extend to higher altitudes than in other areas. In the night time, the stable boundary layer exceeds 900 m in altitude and can sometimes peak at 1750 m, above which the residual layer may reach up to about 4000 m. The daytime convective boundary layer develops rapidly after entering the residual layer, and exceeds 4000 m in thickness. The results show that the deep convective boundary layer in the daytime is a pre-requisite for maintaining the deep residual mixed layer in the night time. Meanwhile, the deep residual mixed layer in the night time provides favorable thermal conditions for the development of the convective boundary layer in the daytime. The prolonged periods of clear weather that often occurs in this area allow the cumulative effect of the atmospheric residual layer to develop fully, which creates thermal conditions beneficial for the growth of the daytime convective boundary layer. At the same time, the land surface process and atmospheric motion within the surface layer in this area also provide helpful support for forming the particular structure of the thermal ABL. High surface temperature is clearly the powerful external thermal forcing for the deep convective boundary layer. Strong sensible heat flux in the surface layer provides the required energy. Highly convective atmosphere and strong turbulence provide the necessary dynamic conditions, and the accumulative effect of the residual layer provides a favorable thermal environment.

关键词： arid region in Northwest China clear days in summer atmospheric boundary layer depth vertical structure land surface process

Inter-Comparison of 10-year Precipitation Simulated by Several RCMs for Asia

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2006年第4期23卷 531-542页

作者：冯锦明符淙斌 START Regional Center for Temperate East Asia and Key Laboratory of Regional Climate-Environmental for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences

In phase Ⅱ of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable resolution model. Comparison of the 10-year simulated precipitation with the observations was carried out. The results show that most models have the capacity to reproduce the basic spatial pattern of precipitation for Asia, and the main rainbelt can be reproduced by most models, but there are distinctions in the location and the intensity. Most models overestimate the precipitation over most continental regions. Interannual variability of the precipitation can also be basically simulated, while differences exist between various models and the observations. The biases in the stream field are important reasons behind the simulation errors of the Regional Climate Models （RCMs）. The cumulus scheme and land surface process have large influences on the precipitation simulation. Generally, the Grell cumulus scheme produces more precipitation than the Kuo scheme.

关键词： RMIP regional climate model interannual variation rainbelt cumulus scheme land surface process

A NUMERICAL SIMULATION OF THE EFFECT ON CHINESE REGIONAL CLIMATE DUE TO SEASONAL VARIATION OF land surface PARAMETERS (PART Ⅱ)

在线全文

学校读者我要写书评

暂无评论

Acta meteorologica Sinica 2001年第2期15卷 323-332页

作者：孙健李维亮周秀骥 Department of Geophysics Peking UniversityBeijing 100871 Chinese Academy of Meteorological Sciences Beijing 100081

The effect on climate due to seasonal variation of vegetation and roughness length was simulated in Part Ⅰ of this essay.In Part Ⅱ,the individual effect of albedo and the joint effect of all those factors (vegetation,roughness length and albedo) were calculated by numerical sensitivity experiments.The results showed that:(1)There is no significant effect on precipitation if the albedo of 4 seasons is used to replace the CRCM's climate average data,but the effect on land surface temperature can be seen clearly.And the effect also can be seen in adjacent regions.(2)If all these three factors are used to replace the CRCM's climate average data at the same time,the effect on precipitation is significant,the most variation value is 300mm.And the effect on temperature is similar to what we can see if only one of these factors in CRCM is replaced by monthly or seasonal data.(3)Seasonal variation of land surface parameters has important effect not only on regional climate,but also on global environment.

关键词： land surface process sensitivity experiments regional climate model vegetation roughness length albedo

同方期刊数据库

The Interannual Variability and Predictability in a Global Climate Model

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 1997年第4期14卷 123-131页

作者：王会军薛峰毕训强 LASG Institute of Atmospheric Physics Chinese Academy of Sciences

The interannual variabilities of the climatological simulation (V1) and the AMIP (Atmospheric Model Intercomparison Project) simulation (V2) by the IAP 9-Level Atmospheric General Circulation Model are studied and discussed in this paper. Based on the analysis of ratio of variability (R) of above two simulations the predictability of the model on the interannual climate variation are studied as well. Results show that V2 is bigger than V1 generally and V2 is more comparable to the real variability of the atmosphere, the major difference of V1 and V2 is in the tropics, for temperature and geopotential height the predictability is higher in the tropics while in the extra-tropics there is almost no predictability and the predictability is bigger in higher level than in lower level. The predictability for precipitation is generally low in the globe, and generally the predictability is high in the tropical eastern Pacific for the lower level. This study suggests that the possible way of increasing the model predictability is the improvement of land surface process modelling and the inclusion of the interannual variations of the land surface conditions (snow cover, albedo, soil moisture, etc.) as the forcing factor for climate modelling and prediction.

关键词： Interannual variability Predictability land surface process