China's complex and twisted journey of SOE reform over the past four decades is an unprecedented transformation in its history and is at the center stage of its economic reforms. Over the past four decades, SOEs tran...China's complex and twisted journey of SOE reform over the past four decades is an unprecedented transformation in its history and is at the center stage of its economic reforms. Over the past four decades, SOEs transitioned from being affiliates of a planned economy to "new SOEs" as modern enterprises under the market economic system. This journey can be roughly divided into the following four stages: the reform to expand SOE autonomy during 1978-1993, the reform to create a modern enterprise system during 1993- 2003, the reform to create a new system for the administration of state assets during 2003- 2013, and the new era of classified SOE reform since 2013. After the four stages, China's SOE reform has made tremendous achievements, particularly since the 18th CPC National Congress. V~th policy readiness for SOE reform in the new era, reform should be carried out in a comprehensive and systematic manner for different types of SOEs in the future.展开更多
What lies ahead for China,difficulties or perhaps another three decades of glory? To address this question,a special event was held at Chongqing Technology and Business University:Symposium on Theories on and Reality ...What lies ahead for China,difficulties or perhaps another three decades of glory? To address this question,a special event was held at Chongqing Technology and Business University:Symposium on Theories on and Reality of China’s 30 Years of Enterprise Reform and Development,annual meeting of the Chinese Institute of Business Administration for 2008. At the foot of a mountain just south of Chongqing,150 delegates in the field of economic research gathered for discussions on pains and gains of the 30 years of reform. Leading economists at the event included Chen Jiagui,vice president of Chinese Academy of Social Sciences (CASS),Zhang Guoyou,vice president of Peking University,and Jin Bei,deputy director of CASS’s Institute of Industrial Economics (IIE). The symposium was jointly sponsored by the Chinese Institute of Business Administration,Jiang Yiwei Academic Foundation for Enterprise Reform and Development,Chongqing Technology and Business University,and CASS Management Science Research Institute. The following is a group of articles written by staff reporters of the China Economist (CE).展开更多
The year 1978 was destined to be an extraordinary year in contemporary Chinese history,which witnessed the convening of the grd Plenary Session of the iuth National Congress of the Communist Party of China,the adoptio...The year 1978 was destined to be an extraordinary year in contemporary Chinese history,which witnessed the convening of the grd Plenary Session of the iuth National Congress of the Communist Party of China,the adoption of reform and opening up policy and setting of new journey of China's diplomacy.展开更多
On June 25,2008,Summit Fo- rum on the Development in the Coming 3 Decades,hosted by China Business Press and sponsored by BMW Brilliance,was held in Beijing Great Wall Sheraton Hotel. World known economists and entrep...On June 25,2008,Summit Fo- rum on the Development in the Coming 3 Decades,hosted by China Business Press and sponsored by BMW Brilliance,was held in Beijing Great Wall Sheraton Hotel. World known economists and entrepre- neurs gathered together to review the ex- perience of China's thirty years of reform and opening up as well as to explore the driving force of China's future develop- ment.China's five famous economists。展开更多
THE non-public economy has played an important role in China’s economic reforms over the past two decades, bringing about great changes to the economy and soci-
Objective: Aim of this study was to investigate the changes in body composition and some biochemical parameters of women at different age and body mass index (BMI) groups and to evaluate their relations with to cardio...Objective: Aim of this study was to investigate the changes in body composition and some biochemical parameters of women at different age and body mass index (BMI) groups and to evaluate their relations with to cardiometabolic risk factors. Methods: The study was created by retrospective research of the file records of total 800 women who got into nutritional counseling between 2002 - 2007 years at Cerrahpasa Medical Faculty. Participants were grouped as 10 - 19, 20 - 29, 30 - 39, 40 - 49, 50 - 59, ≥60 years according to ages and were divided into 4 groups as normal, overweight, obese and morbidly obese according to body mass index. Data were statistically analysed in SPSS for Windows computer program with ANOVA and Tukey HSD tests. Findings: There are significant differences between different age groups in weight, BMI, waist and hip circumferences, percentage of body water, fat and fat-free mass, basal metabolic rate and blood glucose, insulin, triglyceride, cholesterol, HDL, LDL levels and HOMA-IR values. HOMA-IR values were the highest at age group 1 and the lowest at age group 2. Although they were in the same BMI group;their waist circumference, basal metabolic rate and percent of body fat showed significant increases with advancing age. Conclusion: The findings of our study show that it will be useful to use standard values generated for each age group according to BMI levels in predicting increased cardiovascular and metabolic risks together with advancing age. While the lowest rate of obesity according to body fat percent (>30%) was found at the ages in between 20 - 29 (58.4%), it is noteworthy that the obesity rate with respect to their body fat percent has been noticed at the ages of 10 to 19 (2.3%). Comparing with the other groups, significantly higher body heights found at the ages in between 10 - 19, could possibly predicate that the new generations are having better nutrition and overhaul. On the other hand, it was known that as a result of eating bugs and/or over-nutrition, besides insertion of inactive life style, children have become more sensitive to obesity and related health problems. As seen in our study, the healthiest values are at the ages in between 20 - 29, the results were commentated as the women at those ages are showing more interest in their physical appearance and their health. In accordance with our study’s data, in order to cope with obesity and related illnesses, which are having an importance in public health, we concluded that generalizing continuous and effective trainings on nutrition concerning families even the educators starting from the childhood, can be usefull.展开更多
Lawyers play no small a role in improving China’s legal system, which comes along with the country’s endeavor to build a market-oriented economy and open to the outside world. Legal services provided by lawyers have...Lawyers play no small a role in improving China’s legal system, which comes along with the country’s endeavor to build a market-oriented economy and open to the outside world. Legal services provided by lawyers have virtually become available to all sectors of society since the country adopted the policy of reform and opening up in the late 1970s.展开更多
Ⅰ. From the Civilian Contact to the Dual Channel of Official and Non-governmental Exchanges
From 1949 to 1972, S&T exchanges between China and Japan were dominated by civilian contacts,as non-governmental channel...Ⅰ. From the Civilian Contact to the Dual Channel of Official and Non-governmental Exchanges
From 1949 to 1972, S&T exchanges between China and Japan were dominated by civilian contacts,as non-governmental channels were used to intermediate between the two governments. In 1955, a delegation of Chinese scientists visited Japan under the leadership of Guo Moruo, the first president of CAS,and met with Japanese scientists and friends from all walks of life.展开更多
With diplomatic relations going back 60 years, China and Morocco have witnessed great progress in bilateral exchanges and cooperation in various fields during this time. To mark the occasion of the 60th anniversary of...With diplomatic relations going back 60 years, China and Morocco have witnessed great progress in bilateral exchanges and cooperation in various fields during this time. To mark the occasion of the 60th anniversary of ties on November 1, ChinA- ,friea reporter Liu Ting recently spoke to Li Li, China's Ambassador to Morocco, to hear his views on bilateral relations. An edited version of this interview follows.展开更多
I am 61 years old. My hometown is Batang, now part of Sichuan Province. Driven by apoor life, father joined the KMT five days after I was born. His troops went over to the PLA right before national liberation. He join...I am 61 years old. My hometown is Batang, now part of Sichuan Province. Driven by apoor life, father joined the KMT five days after I was born. His troops went over to the PLA right before national liberation. He joined the PLA 18th Army and was sent into Tibet. On the morning of October 17,1950, the PLA forces marched from Mamkang and Dege toward Qamdo, which was garrisoned by Tibetan troops. The latter soon surrendered or were routed. Qamdo was liberated on the 19th. On May 23,1951, the Central Government and the local government of Tibet signed an agreement for the peaceful liberation of Tibet.Join the PLA When 11I joined the PLA to follow in my father’s footsteps in 1951, when I was only 11.1 left Batang on展开更多
Observed hiatus or accelerated warming phenomena are compared with numerical simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) archives,and the associated physical mechanisms are explored ba...Observed hiatus or accelerated warming phenomena are compared with numerical simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) archives,and the associated physical mechanisms are explored based on the CMIP5 models.Decadal trends in total ocean heat content (OHC) are strongly constrained by net top-of-atmosphere (TOA) radiation.During hiatus decades,most CMIP5 models exhibit a significant decrease in the SST and upper OHC and a significant increase of heat penetrating into the subsurface or deep ocean,opposite to the accelerated warming decades.The shallow meridional overturning of the Pacific subtropical cell experiences a significant strengthening (slowdown) for the hiatus (accelerated warming) decades associated with the strengthened (weakened) trade winds over the tropical Pacific.Both surface heating and ocean dynamics contribute to the decadal changes in SST over the Indian Ocean,and the Indonesian Throughflow has a close relationship with the changes of subsurface temperature in the Indian Ocean.The Atlantic Meridional Overturing Circulation (Antarctic Bottom Water) tends to weaken (strengthen) during hiatus decades,opposite to the accelerated warming decades.In short,the results highlight the important roles of air-sea interactions and ocean circulations for modulation of surface and subsurface temperature.展开更多
Previous studies have suggested a poleward shift of the zonally averaged jet stream due to rapid warming over continents.However,the regional characteristics of the change in the jet stream are not yet understood.Here...Previous studies have suggested a poleward shift of the zonally averaged jet stream due to rapid warming over continents.However,the regional characteristics of the change in the jet stream are not yet understood.Here,we present evidence suggesting that the East Asian westerly jet did not shift poleward in past decades(1980-2004 relative to 1958-1979),both in winter and summer.Rather,the jet axis has moved southward in summer,but its meridional position is steady in winter.The main change of the jet stream in winter is the enhancement of its intensity.These changes in both summer and winter are consistent with the corresponding changes in the large meridional tropospheric temperature-gradient zone.Based on these results,we suggest that the changes of the jet stream over East Asia are unique and are different from the zonal mean jet stream over the Northern Hemisphere and over the North Atlantic region.展开更多
Using a homogenized daily maximum temperature(T_(max))dataset across China,this study characterized the spatiotemporal variation of the onset date of extreme hot days in a year(i.e.,FirstEHD)during 1960-2018.Inhomogen...Using a homogenized daily maximum temperature(T_(max))dataset across China,this study characterized the spatiotemporal variation of the onset date of extreme hot days in a year(i.e.,FirstEHD)during 1960-2018.Inhomogeneous trends of FirstEHD over China during 1960-2018 can be found,with the advanced trend of FirstEHD over most parts in China,while a number of stations in North-Central China(NC)show the delayed trend of FirstEHD.Moreover,there exist interdecadal changes of FirstEHD trend,with a remarkable difference in the trend magnitude before and after the 1990s over South China(SC),and the sign of trend can even reverse from negative to positive after the 1990s in Xinjiang(XJ)and Yangtze River Basin(YR),and from positive to negative in NC.The overall trends of FirstEHD over NC,YR,and XJ during 1960-2018 are dominated by the trends before the 1990s,while they are dominated by the sharp advance after the 1990s over SC.It is further found that the trend of FirstEHD can generally be explained by the long-term trend in T_(max) over most parts of China,but the contribution from T_(max) variabilities is also non-negligible and can even account for more than 75% of the overall trend over NC.The possible factors responsible for the decadal changes in FirstEHD trends are also discussed.展开更多
The decadal variability of rainfall and vegetation over West Africa have been studied over the last three decades, 1981-1990, 1991-2000 and 2001-2010 denoted as 1980s, 1990s and 2000s, respectively. Climate Research U...The decadal variability of rainfall and vegetation over West Africa have been studied over the last three decades, 1981-1990, 1991-2000 and 2001-2010 denoted as 1980s, 1990s and 2000s, respectively. Climate Research Unit (CRU) monthly precipitation and Normalized Difference Vegetation Index (NDVI) from the National Oceanic and Atmosphere Administration (NOAA), all covering the period 1981-2010 have been used. This study aimed to assess the changes in the land surface condition and the spatio-temporal distribution of rainfall over West Africa region. The relationship between rainfall and vegetation indices over this region was determined using Pearson’s correlation. Also, the decadal comparison between rainfall and NDVI over the region was based on the significant t-test and the Pearson’s correlation. Results showed that significant return to wet conditions is observed between decade 1980s and decade 1990s over West Africa, and also during decade 2000s with the exception of central Benin and the western Nigeria. Meanwhile, a regreening of the central Sahel and Sudano-Sahel regions is noted. From 1990s to 2000s, this regreening belt is located in the South and the coastal areas: the Guinea Coast, Sudano-Guinea and western Sahel regions. A northward displacement of this re-greening belt is also detected. Thus, a linear relationship occurs between rainfall and NDVI in the Sudanian savannah region, but it is not the case in the rest of West Africa. This may suggest that the re-growth of vegetation in the Sudanian savannah region may be linked to rainfall supplies. Therefore, re-greening over Sahel region in 1990s is related to rainfall recovery. However, this re-greening was not sustained in the decade 2000s due to a slight decrease in rainfall.展开更多
The frequency and duration of observed concurrent hot and dry events(HDEs) over China during the growing season(April–September) exhibit significant decadal changes across the mid-1990s. These changes are characteriz...The frequency and duration of observed concurrent hot and dry events(HDEs) over China during the growing season(April–September) exhibit significant decadal changes across the mid-1990s. These changes are characterized by increases in HDE frequency and duration over most of China, with relatively large increases over southeastern China(SEC), northern China(NC), and northeastern China(NEC). The frequency of HDEs averaged over China in the present day(PD,1994–2011) is double that in the early period(EP, 1964–81);the duration of HDEs increases by 60%. Climate experiments with the Met Office Unified Model(MetUM-GOML2) are used to estimate the contributions of anthropogenic forcing to HDE decadal changes over China. Anthropogenic forcing changes can explain 60%–70% of the observed decadal changes,suggesting an important anthropogenic influence on HDE changes over China across the mid-1990s. Single-forcing experiments indicate that the increase in greenhouse gas(GHG) concentrations dominates the simulated decadal changes,increasing the frequency and duration of HDEs throughout China. The change in anthropogenic aerosol(AA) emissions significantly decreases the frequency and duration of HDEs over SEC and NC, but the magnitude of the decrease is much smaller than the increase induced by GHGs. The changes in HDEs in response to anthropogenic forcing are mainly due to the response of climatological mean surface air temperatures. The contributions from changes in variability and changes in climatological mean soil moisture and evapotranspiration are relatively small. The physical processes associated with the response of HDEs to GHG and AA changes are also revealed.展开更多
Observational analyses demonstrate that the Ural persistent positive height anomaly event(PAE) experienced a decadal increase around the year 2000, exhibiting a southward displacement afterward. These decadal variatio...Observational analyses demonstrate that the Ural persistent positive height anomaly event(PAE) experienced a decadal increase around the year 2000, exhibiting a southward displacement afterward. These decadal variations are related to a large-scale circulation shift over the Eurasian Continent. The effects of underlying sea ice and sea surface temperature(SST) anomalies on the Ural PAE and the related atmospheric circulation were explored by Atmospheric Model Intercomparison Project(AMIP) experiments from the Coupled Model Intercomparison Project Phase 6 and by sensitivity experiments using the Atmospheric General Circulation Model(AGCM). The AMIP experiment results suggest that the underlying sea ice and SST anomalies play important roles. The individual contributions of sea ice loss in the Barents-Kara Seas and the SST anomalies linked to the phase transition of the Pacific Decadal Oscillation(PDO) and Atlantic Multidecadal Oscillation(AMO) are further investigated by AGCM sensitivity experiments isolating the respective forcings.The sea ice decline in Barents-Kara Seas triggers an atmospheric wave train over the Eurasian mid-to-high latitudes with positive anomalies over the Urals, favoring the occurrence of Ural PAEs. The shift in the PDO to its negative phase triggers a wave train propagating downstream from the North Pacific. One positive anomaly lobe of the wave train is located over the Ural Mountains and increases the PAE there. The negative-to-positive transition of the AMO phase since the late-1990s causes positive 500-h Pa height anomalies south of the Ural Mountains, which promote a southward shift of Ural PAE.展开更多
基金' From the two dimensions of modem property ownership system and market-based management system, 'haew SOEs" can be defined as SOEs with modem property ownership systems (characterized by equity diversification and standard corporate governance) and market-based management system (characterized by independent operation, decision-making and management). See "Pre 'hminary Study on New SOEs Phenomenon", China Industrial Economics, Vol.6 2005 by Jin Bei and Huang Qunhui.
文摘China's complex and twisted journey of SOE reform over the past four decades is an unprecedented transformation in its history and is at the center stage of its economic reforms. Over the past four decades, SOEs transitioned from being affiliates of a planned economy to "new SOEs" as modern enterprises under the market economic system. This journey can be roughly divided into the following four stages: the reform to expand SOE autonomy during 1978-1993, the reform to create a modern enterprise system during 1993- 2003, the reform to create a new system for the administration of state assets during 2003- 2013, and the new era of classified SOE reform since 2013. After the four stages, China's SOE reform has made tremendous achievements, particularly since the 18th CPC National Congress. V~th policy readiness for SOE reform in the new era, reform should be carried out in a comprehensive and systematic manner for different types of SOEs in the future.
文摘What lies ahead for China,difficulties or perhaps another three decades of glory? To address this question,a special event was held at Chongqing Technology and Business University:Symposium on Theories on and Reality of China’s 30 Years of Enterprise Reform and Development,annual meeting of the Chinese Institute of Business Administration for 2008. At the foot of a mountain just south of Chongqing,150 delegates in the field of economic research gathered for discussions on pains and gains of the 30 years of reform. Leading economists at the event included Chen Jiagui,vice president of Chinese Academy of Social Sciences (CASS),Zhang Guoyou,vice president of Peking University,and Jin Bei,deputy director of CASS’s Institute of Industrial Economics (IIE). The symposium was jointly sponsored by the Chinese Institute of Business Administration,Jiang Yiwei Academic Foundation for Enterprise Reform and Development,Chongqing Technology and Business University,and CASS Management Science Research Institute. The following is a group of articles written by staff reporters of the China Economist (CE).
文摘The year 1978 was destined to be an extraordinary year in contemporary Chinese history,which witnessed the convening of the grd Plenary Session of the iuth National Congress of the Communist Party of China,the adoption of reform and opening up policy and setting of new journey of China's diplomacy.
文摘On June 25,2008,Summit Fo- rum on the Development in the Coming 3 Decades,hosted by China Business Press and sponsored by BMW Brilliance,was held in Beijing Great Wall Sheraton Hotel. World known economists and entrepre- neurs gathered together to review the ex- perience of China's thirty years of reform and opening up as well as to explore the driving force of China's future develop- ment.China's five famous economists。
文摘THE non-public economy has played an important role in China’s economic reforms over the past two decades, bringing about great changes to the economy and soci-
文摘Objective: Aim of this study was to investigate the changes in body composition and some biochemical parameters of women at different age and body mass index (BMI) groups and to evaluate their relations with to cardiometabolic risk factors. Methods: The study was created by retrospective research of the file records of total 800 women who got into nutritional counseling between 2002 - 2007 years at Cerrahpasa Medical Faculty. Participants were grouped as 10 - 19, 20 - 29, 30 - 39, 40 - 49, 50 - 59, ≥60 years according to ages and were divided into 4 groups as normal, overweight, obese and morbidly obese according to body mass index. Data were statistically analysed in SPSS for Windows computer program with ANOVA and Tukey HSD tests. Findings: There are significant differences between different age groups in weight, BMI, waist and hip circumferences, percentage of body water, fat and fat-free mass, basal metabolic rate and blood glucose, insulin, triglyceride, cholesterol, HDL, LDL levels and HOMA-IR values. HOMA-IR values were the highest at age group 1 and the lowest at age group 2. Although they were in the same BMI group;their waist circumference, basal metabolic rate and percent of body fat showed significant increases with advancing age. Conclusion: The findings of our study show that it will be useful to use standard values generated for each age group according to BMI levels in predicting increased cardiovascular and metabolic risks together with advancing age. While the lowest rate of obesity according to body fat percent (>30%) was found at the ages in between 20 - 29 (58.4%), it is noteworthy that the obesity rate with respect to their body fat percent has been noticed at the ages of 10 to 19 (2.3%). Comparing with the other groups, significantly higher body heights found at the ages in between 10 - 19, could possibly predicate that the new generations are having better nutrition and overhaul. On the other hand, it was known that as a result of eating bugs and/or over-nutrition, besides insertion of inactive life style, children have become more sensitive to obesity and related health problems. As seen in our study, the healthiest values are at the ages in between 20 - 29, the results were commentated as the women at those ages are showing more interest in their physical appearance and their health. In accordance with our study’s data, in order to cope with obesity and related illnesses, which are having an importance in public health, we concluded that generalizing continuous and effective trainings on nutrition concerning families even the educators starting from the childhood, can be usefull.
文摘Lawyers play no small a role in improving China’s legal system, which comes along with the country’s endeavor to build a market-oriented economy and open to the outside world. Legal services provided by lawyers have virtually become available to all sectors of society since the country adopted the policy of reform and opening up in the late 1970s.
文摘Ⅰ. From the Civilian Contact to the Dual Channel of Official and Non-governmental Exchanges
From 1949 to 1972, S&T exchanges between China and Japan were dominated by civilian contacts,as non-governmental channels were used to intermediate between the two governments. In 1955, a delegation of Chinese scientists visited Japan under the leadership of Guo Moruo, the first president of CAS,and met with Japanese scientists and friends from all walks of life.
文摘With diplomatic relations going back 60 years, China and Morocco have witnessed great progress in bilateral exchanges and cooperation in various fields during this time. To mark the occasion of the 60th anniversary of ties on November 1, ChinA- ,friea reporter Liu Ting recently spoke to Li Li, China's Ambassador to Morocco, to hear his views on bilateral relations. An edited version of this interview follows.
文摘I am 61 years old. My hometown is Batang, now part of Sichuan Province. Driven by apoor life, father joined the KMT five days after I was born. His troops went over to the PLA right before national liberation. He joined the PLA 18th Army and was sent into Tibet. On the morning of October 17,1950, the PLA forces marched from Mamkang and Dege toward Qamdo, which was garrisoned by Tibetan troops. The latter soon surrendered or were routed. Qamdo was liberated on the 19th. On May 23,1951, the Central Government and the local government of Tibet signed an agreement for the peaceful liberation of Tibet.Join the PLA When 11I joined the PLA to follow in my father’s footsteps in 1951, when I was only 11.1 left Batang on
基金supported by the National Key Program for Developing Basic Sciences (Grant No.2010CB950502)the "Strategic Priority Research Program Climate Change: Carbon Budget and Relevant Issues" of the Chinese Academy of Sciences (Grant No.XDA05110302)+1 种基金the National Natural Science Foundation of China (Grant No.41376019)the Jiangsu Collaborative Innovation Center for Climate Change
文摘Observed hiatus or accelerated warming phenomena are compared with numerical simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) archives,and the associated physical mechanisms are explored based on the CMIP5 models.Decadal trends in total ocean heat content (OHC) are strongly constrained by net top-of-atmosphere (TOA) radiation.During hiatus decades,most CMIP5 models exhibit a significant decrease in the SST and upper OHC and a significant increase of heat penetrating into the subsurface or deep ocean,opposite to the accelerated warming decades.The shallow meridional overturning of the Pacific subtropical cell experiences a significant strengthening (slowdown) for the hiatus (accelerated warming) decades associated with the strengthened (weakened) trade winds over the tropical Pacific.Both surface heating and ocean dynamics contribute to the decadal changes in SST over the Indian Ocean,and the Indonesian Throughflow has a close relationship with the changes of subsurface temperature in the Indian Ocean.The Atlantic Meridional Overturing Circulation (Antarctic Bottom Water) tends to weaken (strengthen) during hiatus decades,opposite to the accelerated warming decades.In short,the results highlight the important roles of air-sea interactions and ocean circulations for modulation of surface and subsurface temperature.
基金provided by the National Centers for Environmental Prediction (NCEP) and National Center for Atmospheric Research (NCAR)supported by National Natural Science Foundation of China (Grant No41130963)+1 种基金Research Fund for the Doctoral Program of Higher Education (Grant No.20100091110003)the Fundamental Research Funds for the Central Universities(Grant Nos.1184020702 and 1107020730)
文摘Previous studies have suggested a poleward shift of the zonally averaged jet stream due to rapid warming over continents.However,the regional characteristics of the change in the jet stream are not yet understood.Here,we present evidence suggesting that the East Asian westerly jet did not shift poleward in past decades(1980-2004 relative to 1958-1979),both in winter and summer.Rather,the jet axis has moved southward in summer,but its meridional position is steady in winter.The main change of the jet stream in winter is the enhancement of its intensity.These changes in both summer and winter are consistent with the corresponding changes in the large meridional tropospheric temperature-gradient zone.Based on these results,we suggest that the changes of the jet stream over East Asia are unique and are different from the zonal mean jet stream over the Northern Hemisphere and over the North Atlantic region.
基金funded by the National Key Research and De-velopment Program of China[Grant number 2017YFA0604304]the National Natural Science Foundation of China[Grant number 41661144032].
文摘Using a homogenized daily maximum temperature(T_(max))dataset across China,this study characterized the spatiotemporal variation of the onset date of extreme hot days in a year(i.e.,FirstEHD)during 1960-2018.Inhomogeneous trends of FirstEHD over China during 1960-2018 can be found,with the advanced trend of FirstEHD over most parts in China,while a number of stations in North-Central China(NC)show the delayed trend of FirstEHD.Moreover,there exist interdecadal changes of FirstEHD trend,with a remarkable difference in the trend magnitude before and after the 1990s over South China(SC),and the sign of trend can even reverse from negative to positive after the 1990s in Xinjiang(XJ)and Yangtze River Basin(YR),and from positive to negative in NC.The overall trends of FirstEHD over NC,YR,and XJ during 1960-2018 are dominated by the trends before the 1990s,while they are dominated by the sharp advance after the 1990s over SC.It is further found that the trend of FirstEHD can generally be explained by the long-term trend in T_(max) over most parts of China,but the contribution from T_(max) variabilities is also non-negligible and can even account for more than 75% of the overall trend over NC.The possible factors responsible for the decadal changes in FirstEHD trends are also discussed.
文摘The decadal variability of rainfall and vegetation over West Africa have been studied over the last three decades, 1981-1990, 1991-2000 and 2001-2010 denoted as 1980s, 1990s and 2000s, respectively. Climate Research Unit (CRU) monthly precipitation and Normalized Difference Vegetation Index (NDVI) from the National Oceanic and Atmosphere Administration (NOAA), all covering the period 1981-2010 have been used. This study aimed to assess the changes in the land surface condition and the spatio-temporal distribution of rainfall over West Africa region. The relationship between rainfall and vegetation indices over this region was determined using Pearson’s correlation. Also, the decadal comparison between rainfall and NDVI over the region was based on the significant t-test and the Pearson’s correlation. Results showed that significant return to wet conditions is observed between decade 1980s and decade 1990s over West Africa, and also during decade 2000s with the exception of central Benin and the western Nigeria. Meanwhile, a regreening of the central Sahel and Sudano-Sahel regions is noted. From 1990s to 2000s, this regreening belt is located in the South and the coastal areas: the Guinea Coast, Sudano-Guinea and western Sahel regions. A northward displacement of this re-greening belt is also detected. Thus, a linear relationship occurs between rainfall and NDVI in the Sudanian savannah region, but it is not the case in the rest of West Africa. This may suggest that the re-growth of vegetation in the Sudanian savannah region may be linked to rainfall supplies. Therefore, re-greening over Sahel region in 1990s is related to rainfall recovery. However, this re-greening was not sustained in the decade 2000s due to a slight decrease in rainfall.
基金the University of Reading, funded by the UK–China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) China as part of the Newton Fundsupported by the National Natural Science Foundation of China (Grant Nos. 42030603 and 42175044)+1 种基金supported by CSSP-China. NPK was supported by an Independent Research Fellowship from the Natural Environment Research Council (Grant No. NE/L010976/1)supported by the National Centre for Atmospheric Science via the NERC/GCRF programme “Atmospheric hazards in developing countries: risk assessment and early warnings ” (ACREW)。
文摘The frequency and duration of observed concurrent hot and dry events(HDEs) over China during the growing season(April–September) exhibit significant decadal changes across the mid-1990s. These changes are characterized by increases in HDE frequency and duration over most of China, with relatively large increases over southeastern China(SEC), northern China(NC), and northeastern China(NEC). The frequency of HDEs averaged over China in the present day(PD,1994–2011) is double that in the early period(EP, 1964–81);the duration of HDEs increases by 60%. Climate experiments with the Met Office Unified Model(MetUM-GOML2) are used to estimate the contributions of anthropogenic forcing to HDE decadal changes over China. Anthropogenic forcing changes can explain 60%–70% of the observed decadal changes,suggesting an important anthropogenic influence on HDE changes over China across the mid-1990s. Single-forcing experiments indicate that the increase in greenhouse gas(GHG) concentrations dominates the simulated decadal changes,increasing the frequency and duration of HDEs throughout China. The change in anthropogenic aerosol(AA) emissions significantly decreases the frequency and duration of HDEs over SEC and NC, but the magnitude of the decrease is much smaller than the increase induced by GHGs. The changes in HDEs in response to anthropogenic forcing are mainly due to the response of climatological mean surface air temperatures. The contributions from changes in variability and changes in climatological mean soil moisture and evapotranspiration are relatively small. The physical processes associated with the response of HDEs to GHG and AA changes are also revealed.
基金jointly supported by the National Key Research and Development Program of China (Grant No.2018YFA0606403)the National Natural Science Foundation of China (Grant No.41790473)the Beijing Natural Science Foundation (8234068)。
文摘Observational analyses demonstrate that the Ural persistent positive height anomaly event(PAE) experienced a decadal increase around the year 2000, exhibiting a southward displacement afterward. These decadal variations are related to a large-scale circulation shift over the Eurasian Continent. The effects of underlying sea ice and sea surface temperature(SST) anomalies on the Ural PAE and the related atmospheric circulation were explored by Atmospheric Model Intercomparison Project(AMIP) experiments from the Coupled Model Intercomparison Project Phase 6 and by sensitivity experiments using the Atmospheric General Circulation Model(AGCM). The AMIP experiment results suggest that the underlying sea ice and SST anomalies play important roles. The individual contributions of sea ice loss in the Barents-Kara Seas and the SST anomalies linked to the phase transition of the Pacific Decadal Oscillation(PDO) and Atlantic Multidecadal Oscillation(AMO) are further investigated by AGCM sensitivity experiments isolating the respective forcings.The sea ice decline in Barents-Kara Seas triggers an atmospheric wave train over the Eurasian mid-to-high latitudes with positive anomalies over the Urals, favoring the occurrence of Ural PAEs. The shift in the PDO to its negative phase triggers a wave train propagating downstream from the North Pacific. One positive anomaly lobe of the wave train is located over the Ural Mountains and increases the PAE there. The negative-to-positive transition of the AMO phase since the late-1990s causes positive 500-h Pa height anomalies south of the Ural Mountains, which promote a southward shift of Ural PAE.