In this paper, a coupled model was used to estimate the responses of soil moisture and net primary production of vegetation(NPP) to increasing atmospheric CO2 concentration and climate change. The analysis uses three ...In this paper, a coupled model was used to estimate the responses of soil moisture and net primary production of vegetation(NPP) to increasing atmospheric CO2 concentration and climate change. The analysis uses three experiments simulated by the second-generation Earth System Model(CanESM2) of the Canadian Centre for Climate Modelling and Analysis(CCCma), which are part of the phase 5 of the Coupled Model Intercomparison Project(CMIP5). The authors focus on the magnitude and evolution of responses in soil moisture and NPP using simulations modeled by CanESM, in which the individual effects of increasing CO2 concentration and climate change and their combined effect are separately accounted for. When considering only the single effect of climate change, the soil moisture and NPP have a linear trend of 0.03 kg m–2 yr–1 and –0.14 gC m–2 yr–2, respectively. However, such a reduction in the global NPP results from the decrease of NPP at lower latitudes and in the Southern Hemisphere, although increased NPP has been shown in high northern latitudes. The largest negative trend is located in the Amazon basin at –1.79 gC m–2 yr–2. For the individual effect of increasing CO2 concentration, both soil moisture and NPP show increases, with an elevated linear trend of 0.02 kg m–2 yr–1 and 0.84 gC m–2 yr–2, respectively. Most regions show an increasing NPP, except Alaska. For the combined effect of increasing atmospheric CO2 and climate change, the increased soil moisture and NPP exhibit a linear trend of 0.04 kg m–2 yr–1 and 0.83 gC m–2 yr–2 at a global scale. In the Amazon basin, the higher reduction in soil moisture is illustrated by the model, with a linear trend of –0.39 kg m–2 yr–1, for the combined effect. Such a change in soil moisture is caused by a weakened Walker circulation simulated by this coupled model, compared with the single effect of increasing CO2 concentration(experiment M2), and a consequence of the reduction in NPP is also shown in this area, with a linear trend of-0.16 gC m-2 yr-2.展开更多
We give more efficient criteria to characterise prime ideal or primary ideal. Further, we obtain the necessary and sufficient conditions that an ideal is prime or primary in real field from the Grobner bases directly.
基金supported by the project of the National Natural Science Foundation of China (Grant Nos. 41275082 and 41305070)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05110103)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant Nos. KZCX2-EW-QN208 and 7-122158)
文摘In this paper, a coupled model was used to estimate the responses of soil moisture and net primary production of vegetation(NPP) to increasing atmospheric CO2 concentration and climate change. The analysis uses three experiments simulated by the second-generation Earth System Model(CanESM2) of the Canadian Centre for Climate Modelling and Analysis(CCCma), which are part of the phase 5 of the Coupled Model Intercomparison Project(CMIP5). The authors focus on the magnitude and evolution of responses in soil moisture and NPP using simulations modeled by CanESM, in which the individual effects of increasing CO2 concentration and climate change and their combined effect are separately accounted for. When considering only the single effect of climate change, the soil moisture and NPP have a linear trend of 0.03 kg m–2 yr–1 and –0.14 gC m–2 yr–2, respectively. However, such a reduction in the global NPP results from the decrease of NPP at lower latitudes and in the Southern Hemisphere, although increased NPP has been shown in high northern latitudes. The largest negative trend is located in the Amazon basin at –1.79 gC m–2 yr–2. For the individual effect of increasing CO2 concentration, both soil moisture and NPP show increases, with an elevated linear trend of 0.02 kg m–2 yr–1 and 0.84 gC m–2 yr–2, respectively. Most regions show an increasing NPP, except Alaska. For the combined effect of increasing atmospheric CO2 and climate change, the increased soil moisture and NPP exhibit a linear trend of 0.04 kg m–2 yr–1 and 0.83 gC m–2 yr–2 at a global scale. In the Amazon basin, the higher reduction in soil moisture is illustrated by the model, with a linear trend of –0.39 kg m–2 yr–1, for the combined effect. Such a change in soil moisture is caused by a weakened Walker circulation simulated by this coupled model, compared with the single effect of increasing CO2 concentration(experiment M2), and a consequence of the reduction in NPP is also shown in this area, with a linear trend of-0.16 gC m-2 yr-2.
基金Supported by the National Natural Science Foundation of China (No. 11071062)Hunan provincial Natural Science Foundation of China (No. 10JJ3065)+1 种基金Scientific Research Fund of Hunan province education Department (No. 10A033)Hunan Provincial Degree and Education of Graduate Student Foundation (No. JG2009A017)
文摘We give more efficient criteria to characterise prime ideal or primary ideal. Further, we obtain the necessary and sufficient conditions that an ideal is prime or primary in real field from the Grobner bases directly.