This paper applies the newest emission scenarios of the sulfur and greenhouse gases, namely IPCC SRES A2 and B2 scenarios, to investigate the change of the North China climate with an atmosphere-ocean coupled general ...This paper applies the newest emission scenarios of the sulfur and greenhouse gases, namely IPCC SRES A2 and B2 scenarios, to investigate the change of the North China climate with an atmosphere-ocean coupled general circulation model. In the last three decades of the 21st century, the global warming enlarges the land-sea thermal contrast, and hence, causes the East Asian summer (winter) monsoon circulation to he strengthened (weakened). The rainfall seasonality strengthens and the summer precipitation increases significantly in North China. It is suggested that the East Asian rainy area would expand northward to North China in the last three decades of the 21st century. In addition, the North China precipitation would increase significantly in September. In July, August, and September, the interannual variability of the precipitation enlarges evidently over North China, implying a risk of flooding in the future.展开更多
In this paper, we applied the newest emission scenarios of the sulfur and greenhouse gases, i.e. Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 and B2 scenarios, to inv...In this paper, we applied the newest emission scenarios of the sulfur and greenhouse gases, i.e. Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 and B2 scenarios, to investigating the change of the East Asian climate in the last three decades of the 21st century with an atmosphere-ocean coupled general circulation model. The global warming enlarges the land-sea thermal contrast and, hence, enhances (reduces) the East Asian summer (winter) monsoon circulation. The precipitation from the Yangtze and Huaihe river valley to North China increases significantly. In particular, the strong rainfall increase over North China implies that the East Asian rainy area would expand northward. In addition, from the southeastern coastal area to North China, the rainfall would increase significantly in September, implying that the rainy period of the East Asian monsoon would be prolonged about one month. In July, August and September, the interannual variability of the precipitation enhances evidently over North China, meaning a risk of flooding in the future.展开更多
采用了DSSAT作物模式和区域气候模式相连接,模拟分析了A2和B2气候变化情景对中国主要地区灌溉水稻产量的影响。气候变化情景采用了IPCC发布的SRES(Special Report on Emissions Scenarios)系列的最新温室气体排放情景,气候情景值采用区...采用了DSSAT作物模式和区域气候模式相连接,模拟分析了A2和B2气候变化情景对中国主要地区灌溉水稻产量的影响。气候变化情景采用了IPCC发布的SRES(Special Report on Emissions Scenarios)系列的最新温室气体排放情景,气候情景值采用区域气候模式PRECIS(Provide Regional Climates for Impact Studies)的模拟值。通过研究站点水稻对A2和B2增温梯度敏感性的分析表明:温度增加,水稻产量呈下降趋势,随着温度增加,产量下降幅度增大。且在同一增温水平下,在南方热带地区的昆明和海口,产量下降幅度大于其他站点。A2和B2的产量相对于基准年(1961~1990年)的变化分别为:气候变化对不同站点的年代际水稻平均产量表现了正面或负面的影响(A2情景下为2.3%^-10.2%,B2情景下为4.0%^-13.6%),在某一些站点,水稻高产年和低产年的概率明显增加,产量分布趋于两极化。展开更多
As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-197...As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present. The decadal change of ＂tropical cyclones activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclone. Furthermore, based on the simulation of corresponding atmospheric general circulation from a coupled climate model under the schemes of Intergovemmental Panel on Climate Change （IPCC）,special report on emission scenarios （SRES） A2 and B2 emissions scenarios an outlook on the tropical cyclone frequency generated over the western North Pacific in the coming half century is presented. It is indicated that in response to the global climate change the general circulation of atmosphere would become unfavorable for the formation of tropical cyclone as a whole and the frequency of tropical cyclones formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period in it.展开更多
Single crystals of undoped (pure) and barium nitrate (Ba (NO3)2)-doped L-Valinium Picrate (LVP) were grown from aqueous solution by slow evaporation technique. Morphological changes have been observed when Ba (NO3)2) ...Single crystals of undoped (pure) and barium nitrate (Ba (NO3)2)-doped L-Valinium Picrate (LVP) were grown from aqueous solution by slow evaporation technique. Morphological changes have been observed when Ba (NO3)2) is doped into LVP crystals. The dopant concentration in the crystals was measured by ICP technique. Slight changes in the unit cell parameter of LVP after doping with Ba (NO3)2) have been detected. The powder X-ray diffraction of the grown crystals has been recorded and the various planes of reflection identified shows shift in the peak positions. FTIR and UV spectra reveal the functional group identification and optical property of the grown crystals. The relative second harmonic generation (SHG) efficiency measurements revealed that both 5 and 10 mol % of Ba (NO3)2) in LVP enhanced the SHG efficiency by 92.85 and 160.59 times that of KDP respectively. However, at higher concentration, SHG efficiency is not increased but rather decreased from it undoped condition. Microhardness studies show that hardness number (Hv) increased with increase in load for all the grown crystals of this work.展开更多
基金supported by the Key Project of the Chinese Academy of Sciences(KZCX2-SW-210)the Key Project of the Chinese Academy of Sciences(KZCX2-203)the National Key Programme for Developing Basic Sciences(G1998040904).
文摘This paper applies the newest emission scenarios of the sulfur and greenhouse gases, namely IPCC SRES A2 and B2 scenarios, to investigate the change of the North China climate with an atmosphere-ocean coupled general circulation model. In the last three decades of the 21st century, the global warming enlarges the land-sea thermal contrast, and hence, causes the East Asian summer (winter) monsoon circulation to he strengthened (weakened). The rainfall seasonality strengthens and the summer precipitation increases significantly in North China. It is suggested that the East Asian rainy area would expand northward to North China in the last three decades of the 21st century. In addition, the North China precipitation would increase significantly in September. In July, August, and September, the interannual variability of the precipitation enlarges evidently over North China, implying a risk of flooding in the future.
基金supported by the Key Project of the Chinese Academy of Sciences(Grant Nos.KZCX2-SW-210 and KZCX2-203)the National Key Programme for Developing Basic Sciences(Grant No.G1998040904)the National Natural Science Foundation of China(Grant No.40105006).
文摘In this paper, we applied the newest emission scenarios of the sulfur and greenhouse gases, i.e. Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 and B2 scenarios, to investigating the change of the East Asian climate in the last three decades of the 21st century with an atmosphere-ocean coupled general circulation model. The global warming enlarges the land-sea thermal contrast and, hence, enhances (reduces) the East Asian summer (winter) monsoon circulation. The precipitation from the Yangtze and Huaihe river valley to North China increases significantly. In particular, the strong rainfall increase over North China implies that the East Asian rainy area would expand northward. In addition, from the southeastern coastal area to North China, the rainfall would increase significantly in September, implying that the rainy period of the East Asian monsoon would be prolonged about one month. In July, August and September, the interannual variability of the precipitation enhances evidently over North China, meaning a risk of flooding in the future.
文摘采用了DSSAT作物模式和区域气候模式相连接,模拟分析了A2和B2气候变化情景对中国主要地区灌溉水稻产量的影响。气候变化情景采用了IPCC发布的SRES(Special Report on Emissions Scenarios)系列的最新温室气体排放情景,气候情景值采用区域气候模式PRECIS(Provide Regional Climates for Impact Studies)的模拟值。通过研究站点水稻对A2和B2增温梯度敏感性的分析表明:温度增加,水稻产量呈下降趋势,随着温度增加,产量下降幅度增大。且在同一增温水平下,在南方热带地区的昆明和海口,产量下降幅度大于其他站点。A2和B2的产量相对于基准年(1961~1990年)的变化分别为:气候变化对不同站点的年代际水稻平均产量表现了正面或负面的影响(A2情景下为2.3%^-10.2%,B2情景下为4.0%^-13.6%),在某一些站点,水稻高产年和低产年的概率明显增加,产量分布趋于两极化。
基金This work was supported by the National Natural Science Foundation of China under contract No.40375034the Special Climate Project of China Meteorological Administration.
文摘As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present. The decadal change of ＂tropical cyclones activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclone. Furthermore, based on the simulation of corresponding atmospheric general circulation from a coupled climate model under the schemes of Intergovemmental Panel on Climate Change （IPCC）,special report on emission scenarios （SRES） A2 and B2 emissions scenarios an outlook on the tropical cyclone frequency generated over the western North Pacific in the coming half century is presented. It is indicated that in response to the global climate change the general circulation of atmosphere would become unfavorable for the formation of tropical cyclone as a whole and the frequency of tropical cyclones formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period in it.
文摘Single crystals of undoped (pure) and barium nitrate (Ba (NO3)2)-doped L-Valinium Picrate (LVP) were grown from aqueous solution by slow evaporation technique. Morphological changes have been observed when Ba (NO3)2) is doped into LVP crystals. The dopant concentration in the crystals was measured by ICP technique. Slight changes in the unit cell parameter of LVP after doping with Ba (NO3)2) have been detected. The powder X-ray diffraction of the grown crystals has been recorded and the various planes of reflection identified shows shift in the peak positions. FTIR and UV spectra reveal the functional group identification and optical property of the grown crystals. The relative second harmonic generation (SHG) efficiency measurements revealed that both 5 and 10 mol % of Ba (NO3)2) in LVP enhanced the SHG efficiency by 92.85 and 160.59 times that of KDP respectively. However, at higher concentration, SHG efficiency is not increased but rather decreased from it undoped condition. Microhardness studies show that hardness number (Hv) increased with increase in load for all the grown crystals of this work.
