To ensure the effectiveness of the operation of artificial precipitation enhancement, a potential region for the operation should be determined in advance.As cloud microphysical measurements needed for the determinati...To ensure the effectiveness of the operation of artificial precipitation enhancement, a potential region for the operation should be determined in advance.As cloud microphysical measurements needed for the determination of the potential region of cloud seeding are not available before the operation of routine precipitation enhancement, a new method based on the growth process of ice crystal is put forward for determining the potential region using the numerical weather prediction model output.The ice supersaturation, accumulated water vapor within minus temperature layer (≥9 mm), and upward water vapor transportation are adopted as criteria to determine the potential time, height and region of cloud seeding, and the real-time radar images are applied to make decisions on the seeding commanding.The criteria and Doppler radar images are studied in a case of precipitation enhancement characterized by significant water vapor supply from the north part of a tropical cyclone in the northwest Pacific, which shows that the ocean plays a crucial role in the advection transportation of water vapor to the potential region of the coastal area.The study presents a new method to determine the potential region of precipitation enhancement using macro-physical quantities under ice crystal growth environment.The method possesses a clear physical significance and can be readily applied with the required and easily predicted parameters.展开更多
Further utilization of global agricultural resources and the expansion of potential international cooperation space are necessary measures to promote a new level of China's national food security and optimize the ...Further utilization of global agricultural resources and the expansion of potential international cooperation space are necessary measures to promote a new level of China's national food security and optimize the structure of domestic food consumption.This study measured the global potential cultivated land area and national grain self-sufficiency.Based on the two-above measures,the authors made a classification of China's foreign agricultural cooperation countries and depicted the spatial pattern of cooperation based on the grain trades of those countries with China.The:grain exporters include Australia,North America,South America,Eastern Europe and Central Asia;and the target countries for "going abroad"of Chinese grain enterprises are mainly located in Sub-Saharan Africa and northern Latin America.This study proposes that China's policy of cooperation on grain should be shifted to non-traditional partners alongside the "Belt and Road Initiative"region.Specifically,China could expand grain imports from Russia,Kazakhstan,Ukraine and other East European and Central Asian countries,and the direction for China's agricultural enterprises "going abroad"should shift to Sub-Sahara Africa.展开更多
基金the support from the Meteoro-logical Science and Technology Research Project (2009-sdqz05),Shandong Meteorological Bureau
文摘To ensure the effectiveness of the operation of artificial precipitation enhancement, a potential region for the operation should be determined in advance.As cloud microphysical measurements needed for the determination of the potential region of cloud seeding are not available before the operation of routine precipitation enhancement, a new method based on the growth process of ice crystal is put forward for determining the potential region using the numerical weather prediction model output.The ice supersaturation, accumulated water vapor within minus temperature layer (≥9 mm), and upward water vapor transportation are adopted as criteria to determine the potential time, height and region of cloud seeding, and the real-time radar images are applied to make decisions on the seeding commanding.The criteria and Doppler radar images are studied in a case of precipitation enhancement characterized by significant water vapor supply from the north part of a tropical cyclone in the northwest Pacific, which shows that the ocean plays a crucial role in the advection transportation of water vapor to the potential region of the coastal area.The study presents a new method to determine the potential region of precipitation enhancement using macro-physical quantities under ice crystal growth environment.The method possesses a clear physical significance and can be readily applied with the required and easily predicted parameters.
基金The Strategic Priority Research Program of Chinese Academy of Sciences(XDA19030200)The Key Deployment Project of Chinese Academy of Sciences(KJZD-EW-G20)
文摘Further utilization of global agricultural resources and the expansion of potential international cooperation space are necessary measures to promote a new level of China's national food security and optimize the structure of domestic food consumption.This study measured the global potential cultivated land area and national grain self-sufficiency.Based on the two-above measures,the authors made a classification of China's foreign agricultural cooperation countries and depicted the spatial pattern of cooperation based on the grain trades of those countries with China.The:grain exporters include Australia,North America,South America,Eastern Europe and Central Asia;and the target countries for "going abroad"of Chinese grain enterprises are mainly located in Sub-Saharan Africa and northern Latin America.This study proposes that China's policy of cooperation on grain should be shifted to non-traditional partners alongside the "Belt and Road Initiative"region.Specifically,China could expand grain imports from Russia,Kazakhstan,Ukraine and other East European and Central Asian countries,and the direction for China's agricultural enterprises "going abroad"should shift to Sub-Sahara Africa.
