Heat budget analysis in three typical warm periods simulated by FGOALS-s2

This study compared basic warming patterns among three typical warm periods — the midHolocene（MH）, Medieval Warm Period（MWP）, and the twentieth century warming（20CW） — and carried out a comprehensive heat budget analysis using four experiments simulated by the Flexible Global Ocean–Atmosphere–Land System model, Spectral Version 2（FGOALS-s2）. The model simulates similar spatial warming patterns in all three warm periods, e.g. stronger warming appears in the high latitudes. However, changes in surface air temperature（SAT） over the tropical regions are different： a significant warming occurs in the 20 CW and MWP but a significant cooling in the MH. The heat budget analysis suggested that SAT changes are mainly induced by the heat flux. In the MH, the insolation and positive snow and ice feedback are responsible for the warming in the Southern Ocean but the wind anomalies and decreased downward longwave radiation（DLR） induce the cooling in the tropics. In the 20 CW, the decreased shortwave radiation and increased sea surface temperature dependency of evaporation dampen the warming in the tropics. In the MWP, the shortwave radiation induces the Southern Ocean warming, but the DLR and wind anomalies warm the SAT in the tropics. The simulated ocean temperature and ocean heat content anomalies are different in the upper ocean（above 1500 m）, which are mainly induced by the wind stress changes, but similar in the deep ocean in all three warm periods.

地理思维模型在高中地理教学中的应用——以“收—支”模型的建构为例

探寻高中地理基本概念、原理、过程背后的地理思维模型,能帮助学生搭建认知相关概念、原理或过程的桥梁。其中解释资源、物质和能量增减的"收-支"模型是解释热量变化、水量变化和地表物质迁移等地理问题的重要思维模型。文章以"收-支"模型为例,探求地理思维模型在高中地理课堂中的应用途径。

Global and Regional Impacts of Vegetation on the Hydrological Cycle and Energy Budget as Represented by the Community Atmosphere Model (CAM3)

The effects of vegetation and its seasonal variation on energy and the hydrological cycle were examined using a state-of-the-art Community Atmosphere Model （CAM3）. Three 15-year numerical experiments were completed： the first with realistic vegetation characteristics varying monthly （VEG run）, the second without vegetation over land （NOVEG run）, and the third with the vegetation characteristics held at their annual mean values （VEGMEAN run）. In these models, the hydrological cycle and land surface energy budget were widely affected by vegetation. Globaland annual-mean evapotranspiration significantly increased compared with the NOVEG by 11.8% in the VEG run run, while runoff decreased by 13.2% when the realistic vegetation is incorporated. Vegetation plays different roles in different regions. In tropical Asia, vegetation-induced cooling of the land surface plays a crucial role in decreasing tropical precipitation. In middle latitudes and the Amazon region, however, the vegetation-induced increase of evapotranspiration plays a more important role in increasing precipitation. The seasonal variation of vegetation also shows clear influences on the hydrological cycle and energy budget. In the boreal mid-high latitudes where vegetation shows a strong seasonal cycle, evapotranspiration and precipitation are higher in the summer in the VEG run than in the VEGMEAN run.

Sensitivity analysis of the De Nitrification and De Composition model for simulating regional carbon budget at the wetlandgrassland area on the Zoige Plateau,China

Although mathematical models(e.g., De Nitrification and De Composition(DNDC) provide a powerful tool to study regional carbon budget, it is still difficult to obtain accurate simulation results because there exists large uncertainties in modeling regional carbon budget. Through the investigation on the sensitivity of model output parameters to the input parameters, sensitivity analysis(SA) has been proved to be able to identify the key sources of uncertainties and be helpful to reduce the model uncertainties. However, some input parameters with discrete values(e.g., land use type and soil type) and the regional effect of the sensitive parameters were rarely examined in SA. In this paper, taking the Zoige Plateau as a case area, we combined the one-factor-ata-time(OAT) with Extended Fourier Amplitude Sensitivity Test(EFAST) to conduct a SA of DNDC for simulating the regional carbon budget, including Gross Primary Productivity(GPP), Net Primary Productivity(NPP), Net Ecosystem Productivity(NEP), autotrophic respiration(Ra), soil microbial heterotrophic respiration(Rh) and ecosystem respiration(Re). The result showed that the combination of OAT and EFAST could test the contribution of the input parameters with discrete values to the output parameters. In DNDC model, land use type and soil type had a significant impact on the regional carbon budget of the Zoige Plateau, and daily temperature was also confirmed to be one of the most important parameters for carbon budget. For the other input parameters, with the change of land use type or soil type at regional scale, the sensitive parameters of carbon budget would vary accordingly. The SA results would provide scientific evidence to optimize DNDC model and they suggested that we should pay attention to the spatial/temporal effect of SA and try to use the appropriate data in simulation of the regional carbon budget.

A study of inadequate consumer demand among Chinese residents --based on data for urban and rural areas in different provinces

Using panel data from both urban and rural areas in China＇s thirty provinces, autonomous regions and municipalities （Tibet excluded） from 1995 to 2005 and applying the random effects model, we conducted a quantitative analysis of factors influencing urban and rural consumer demand. The findings show the per capita disposable income of Chinese residents is highly correlated with their per capita consumption expenditure and the consumption function of urban and rural residents was relatively stable over the eleven years under study. On the basis of these findings, this paper further makes use of data in China＇s funds flow statements （physical transactions） from 1992 to 2004 to explain one of the reasons for the continuing under-consumption since 1997-1998; that is, in the course of national income distribution and redistribution the government has gained an ever increasing share of total and disposable income while the share of Chinese residents shows a continuous decline.