The dynamics of eastward shifting cyclonic vortices are investigated in terms of a barotropic primitive equation model, and six experiments are performed. Both the interaction of a cyclonic vortex with vorticity lumps...The dynamics of eastward shifting cyclonic vortices are investigated in terms of a barotropic primitive equation model, and six experiments are performed. Both the interaction of a cyclonic vortex with vorticity lumps and the interaction of the vortex with the shearing basic flow may induce the strengthening of the vortex in a short period, however, the vortex intensity still shows a general decreasing tendency over the whole integration time period. The interaction among the shearing basic flow, cyclonic vortex, and multiple vorticity lumps can change the tendency. The merging of the cyclonic vortex with vorticity lumps in the shearing basic flow of positive vorticity is directly responsible for the maintenance and development of the cyclonic vortex.展开更多
Northward propagation in summer and eastward propagation in winter are two distinguished features of tropical intraseasonal oscillation （TISO） over the equatorial Indian Ocean. According to numerical modeling result...Northward propagation in summer and eastward propagation in winter are two distinguished features of tropical intraseasonal oscillation （TISO） over the equatorial Indian Ocean. According to numerical modeling results, under a global warming scenario, both propagations were intensified. The enhanced northward propagation in summer can be attributed to the enhanced atmosphere-ocean interaction and the strengthened mean southerly wind; and the intensified eastward propagation in winter is associated with the enhanced convection-wind coupling process and the strengthened equatorial Kevin wave. Future changes of TISO propagations need to be explored in more climate models.展开更多
Based on multiple datasets, correlation and composite analyses, and case studies, this paper investigated possible influences of the Indian Ocean dipole(IOD) mode on the eastward propagation of intraseasonal oscillati...Based on multiple datasets, correlation and composite analyses, and case studies, this paper investigated possible influences of the Indian Ocean dipole(IOD) mode on the eastward propagation of intraseasonal oscillation in the tropical atmosphere. The results showed that(1) the 30-60 day outgoing longwave radiation anomalies in the southeastern Indian Ocean and the 30-60 day 850-hPa zonal wind anomalies over the equatorial central Indian Ocean were significantly correlated with the IOD index;(2) during positive IOD years, the anomalously cold water in the southeastern Indian Ocean and the 850-hPa anomalous easterlies over the equatorial central Indian Ocean might act as barriers to the continuously eastward propagation of the intraseasonal convection, which interrupts the Madden-Julian oscillation(MJO) propagation in the eastern equatorial Indian Ocean and western Pacific; and(3) during negative IOD years, the anomalously warm water in the southeastern Indian Ocean and the low-level westerly anomalies over the equatorial central Indian Ocean favor the eastward movement of MJO.展开更多
The“Eastward Migration Festival”is an emerging festival initiated by Yugur scholars,with the collective participation of the masses,and held in some areas of the Yugur,now held four times.As it carries the collectiv...The“Eastward Migration Festival”is an emerging festival initiated by Yugur scholars,with the collective participation of the masses,and held in some areas of the Yugur,now held four times.As it carries the collective heritage of the Yugur people,the“Eastward Migration Festival”draws on Pierre Nora’s theory of“Les Lieux de Memoire”,and explains why the“Eastward Migration Festival”activity has become the“Les Lieux de Memoire”of Yugur society from three aspects:history,symbol and narrative.展开更多
At 8:30 on October 27, the first international flight from Shanghai to Singapore MU576 took off at Pudong Airport. Thus,all international flights and those to Hong Kong and Macao were all moved to Pudong Airport. Besi...At 8:30 on October 27, the first international flight from Shanghai to Singapore MU576 took off at Pudong Airport. Thus,all international flights and those to Hong Kong and Macao were all moved to Pudong Airport. Besides internationalflights and Hong Kong and Macao flights, the eastward moving also cover some domestic flights, namely flights fromSanya, Haikou, Guangzhou, Shenzhen, Zhuhai, Qingdao, Yantai, Weihai, Weifang and so on in Northwest China, Mid-South China,and East China to Shanghai. After the eastward moving, the flight distribution at two airports in Shanghai changed greatly.展开更多
The monthly circulations on isopycnal surface in the western North Pacific are calculated based on the Navy’s Generalized Digital Environmental Model climatological tem-perature and salinity data on a 1/2°×...The monthly circulations on isopycnal surface in the western North Pacific are calculated based on the Navy’s Generalized Digital Environmental Model climatological tem-perature and salinity data on a 1/2°×1/2°grid using a P-vector method.The eastward Sub-tropical Countercurrent(STCC)in the central subtropical gyre has been studied with emphasis on its spatial distribution,vertical structure,volume transport and its nearby eddy phenomenon.The results reproduce the observed feature of STCC,and reveal some new phenomena on isopycnal surface,such as:(1)Atσθ=24.6,there is strong seasonal variability in the distribution,origin and flow status of STCC.There is no STCC in January,February and March.(2)From May to October,a branch of the Kuroshio Countercurrent to the south of Japan merges into STCC,which increases the velocity of STCC and widens its width.(3)The velocity vector field shows that STCC and nearby eddies coexist.(4)The eastward volume transport of STCC across 137.5°E is the strongest in summer with the maximum of 6.9 Sv(1 Sv≡106 m3 s?1)in August,and weaker in spring and autumn with 1.7 Sv in April and 1.6 Sv in November.Most of the transports of STCC occur between isopycnal surfaces 24.0σθand 25.0σθ.(5)The distributions of the zonal flow along 137.5°E show that the flow core of STCC is between 24.3σθand 24.7σθ.展开更多
It is generally considered that the occurrence of glacial-interglacial gyrations can be explained with the Milankovitch theory.However,the solutions of some problems in the theory are currently not derived yet.After r...It is generally considered that the occurrence of glacial-interglacial gyrations can be explained with the Milankovitch theory.However,the solutions of some problems in the theory are currently not derived yet.After researching the eastward dust transport from Central Asia,we have found that there is a positive feedback mechanism between the eastward dust transport and the global temperature decrease.This magnifies the effect of solar radiation change in the high-latitude Hemisphere,and results in area of the Northern the occurrence of the global glacial epoch.The positive feedback mechanism starts with the reduction of solar radiation in the high-latitude area of the Northern Hemisphere.Subsequently,the global temperature decreases and global glacial epoch occurs,in which the pivotal fac-tor is the eastward dust transport from Central Asia.With the theory of the positive feedback mechanism,some problems in the Milankovitch theory can be solved well.展开更多
Within the framework of forcing/dissipation KDV dynamics, the effect is numerically studied of successive east-travelling troughs on quasi-stationary high's ridges downstream. Results show that two types of low-fr...Within the framework of forcing/dissipation KDV dynamics, the effect is numerically studied of successive east-travelling troughs on quasi-stationary high's ridges downstream. Results show that two types of low-fre- quency transiency are available, depending on the intensities of down-drifting troughs. One is that transiency occurs in strength, i.e., the ridge undergoes transient change in intensity with unchanged position; the other is that transiency takes place in pattern, viz., the breakdown of the quasi-stationary character of the ridge's posi- tion, meaning that the ridge is replaced by a trough, followed by multiple transformation between ridge and trough.展开更多
The period of strategic opportunities for China’s development, in terms of international environment, means the environment, opportunities, conditions and the time limits provided by the period of strategic opportuni...The period of strategic opportunities for China’s development, in terms of international environment, means the environment, opportunities, conditions and the time limits provided by the period of strategic opportunities. Since the U.S. eastward shift of its strategic focus, the changing China-U.S. relations and major powers games will exert tremendous impacts on the period of strategic opportunities and lead to three new characteristics featuring a more complicated and changeable strategic posture, controllable crisis management and universal values.展开更多
Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.Americ...Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.America’s“natural gas independence”has reshaped the global natural gas market,creating a new pattern of“supply shifting westward and consumption shifting eastward”.展开更多
基金the National Natural Science Foundation under Grant No.49775263the project of the Tibetan Plateau Experiment(TIPEX)of Atmospheric Science and the 973 Project onheavy rain in China.
文摘The dynamics of eastward shifting cyclonic vortices are investigated in terms of a barotropic primitive equation model, and six experiments are performed. Both the interaction of a cyclonic vortex with vorticity lumps and the interaction of the vortex with the shearing basic flow may induce the strengthening of the vortex in a short period, however, the vortex intensity still shows a general decreasing tendency over the whole integration time period. The interaction among the shearing basic flow, cyclonic vortex, and multiple vorticity lumps can change the tendency. The merging of the cyclonic vortex with vorticity lumps in the shearing basic flow of positive vorticity is directly responsible for the maintenance and development of the cyclonic vortex.
基金supported by the "973" projects (Grant Nos. 2012CB417203,2012CB955400,and 2013CB955803) "863" project (Grant No.2010AA012305)NSFC (Grant Nos. 41005036 and 41023002)
文摘Northward propagation in summer and eastward propagation in winter are two distinguished features of tropical intraseasonal oscillation （TISO） over the equatorial Indian Ocean. According to numerical modeling results, under a global warming scenario, both propagations were intensified. The enhanced northward propagation in summer can be attributed to the enhanced atmosphere-ocean interaction and the strengthened mean southerly wind; and the intensified eastward propagation in winter is associated with the enhanced convection-wind coupling process and the strengthened equatorial Kevin wave. Future changes of TISO propagations need to be explored in more climate models.
基金National Science foundation of China(41005038)Chinese Public Sector(Meteorology)Research and Special Project(GYHY200906016)National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2009BAC51B01,2009BAC51B02)
文摘Based on multiple datasets, correlation and composite analyses, and case studies, this paper investigated possible influences of the Indian Ocean dipole(IOD) mode on the eastward propagation of intraseasonal oscillation in the tropical atmosphere. The results showed that(1) the 30-60 day outgoing longwave radiation anomalies in the southeastern Indian Ocean and the 30-60 day 850-hPa zonal wind anomalies over the equatorial central Indian Ocean were significantly correlated with the IOD index;(2) during positive IOD years, the anomalously cold water in the southeastern Indian Ocean and the 850-hPa anomalous easterlies over the equatorial central Indian Ocean might act as barriers to the continuously eastward propagation of the intraseasonal convection, which interrupts the Madden-Julian oscillation(MJO) propagation in the eastern equatorial Indian Ocean and western Pacific; and(3) during negative IOD years, the anomalously warm water in the southeastern Indian Ocean and the low-level westerly anomalies over the equatorial central Indian Ocean favor the eastward movement of MJO.
基金This essay is an achievement of the project“Graduate Research and Innovation Project”(Yxm 2019002)funded by Northwest Minzu University,China。
文摘The“Eastward Migration Festival”is an emerging festival initiated by Yugur scholars,with the collective participation of the masses,and held in some areas of the Yugur,now held four times.As it carries the collective heritage of the Yugur people,the“Eastward Migration Festival”draws on Pierre Nora’s theory of“Les Lieux de Memoire”,and explains why the“Eastward Migration Festival”activity has become the“Les Lieux de Memoire”of Yugur society from three aspects:history,symbol and narrative.
文摘At 8:30 on October 27, the first international flight from Shanghai to Singapore MU576 took off at Pudong Airport. Thus,all international flights and those to Hong Kong and Macao were all moved to Pudong Airport. Besides internationalflights and Hong Kong and Macao flights, the eastward moving also cover some domestic flights, namely flights fromSanya, Haikou, Guangzhou, Shenzhen, Zhuhai, Qingdao, Yantai, Weihai, Weifang and so on in Northwest China, Mid-South China,and East China to Shanghai. After the eastward moving, the flight distribution at two airports in Shanghai changed greatly.
基金the Key Project of the Chinese Academy of Sciences(CAS)(Grant No.KZCX1-sw-01-16)the National Natural Science Foundation of China(Grant Nos.40076009,90411011)the One Hundred Talents Project of CAS.
文摘The monthly circulations on isopycnal surface in the western North Pacific are calculated based on the Navy’s Generalized Digital Environmental Model climatological tem-perature and salinity data on a 1/2°×1/2°grid using a P-vector method.The eastward Sub-tropical Countercurrent(STCC)in the central subtropical gyre has been studied with emphasis on its spatial distribution,vertical structure,volume transport and its nearby eddy phenomenon.The results reproduce the observed feature of STCC,and reveal some new phenomena on isopycnal surface,such as:(1)Atσθ=24.6,there is strong seasonal variability in the distribution,origin and flow status of STCC.There is no STCC in January,February and March.(2)From May to October,a branch of the Kuroshio Countercurrent to the south of Japan merges into STCC,which increases the velocity of STCC and widens its width.(3)The velocity vector field shows that STCC and nearby eddies coexist.(4)The eastward volume transport of STCC across 137.5°E is the strongest in summer with the maximum of 6.9 Sv(1 Sv≡106 m3 s?1)in August,and weaker in spring and autumn with 1.7 Sv in April and 1.6 Sv in November.Most of the transports of STCC occur between isopycnal surfaces 24.0σθand 25.0σθ.(5)The distributions of the zonal flow along 137.5°E show that the flow core of STCC is between 24.3σθand 24.7σθ.
基金supported by the National Natural Science Foundation of China(Grant No.40475041)Special Subject of Climate Change of China Meteorological Administration(Grant No.CCSF2005-3-DH14)China Desert Meteorological Science Foundation(Grant No.SQJ2004002).
文摘It is generally considered that the occurrence of glacial-interglacial gyrations can be explained with the Milankovitch theory.However,the solutions of some problems in the theory are currently not derived yet.After researching the eastward dust transport from Central Asia,we have found that there is a positive feedback mechanism between the eastward dust transport and the global temperature decrease.This magnifies the effect of solar radiation change in the high-latitude Hemisphere,and results in area of the Northern the occurrence of the global glacial epoch.The positive feedback mechanism starts with the reduction of solar radiation in the high-latitude area of the Northern Hemisphere.Subsequently,the global temperature decreases and global glacial epoch occurs,in which the pivotal fac-tor is the eastward dust transport from Central Asia.With the theory of the positive feedback mechanism,some problems in the Milankovitch theory can be solved well.
基金This work is supported in part by National Natural Science Foundation of Chinain part by the State Meteorological Adiministration Climate Research Funds.
文摘Within the framework of forcing/dissipation KDV dynamics, the effect is numerically studied of successive east-travelling troughs on quasi-stationary high's ridges downstream. Results show that two types of low-fre- quency transiency are available, depending on the intensities of down-drifting troughs. One is that transiency occurs in strength, i.e., the ridge undergoes transient change in intensity with unchanged position; the other is that transiency takes place in pattern, viz., the breakdown of the quasi-stationary character of the ridge's posi- tion, meaning that the ridge is replaced by a trough, followed by multiple transformation between ridge and trough.
文摘The period of strategic opportunities for China’s development, in terms of international environment, means the environment, opportunities, conditions and the time limits provided by the period of strategic opportunities. Since the U.S. eastward shift of its strategic focus, the changing China-U.S. relations and major powers games will exert tremendous impacts on the period of strategic opportunities and lead to three new characteristics featuring a more complicated and changeable strategic posture, controllable crisis management and universal values.
文摘Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.America’s“natural gas independence”has reshaped the global natural gas market,creating a new pattern of“supply shifting westward and consumption shifting eastward”.
