This study focuses on the climatic impacts of the Atlantic Multidecadal Oscillation （AMO） as a mode of internal vari- ability. Given the difficulties involved in excluding the effects of external forcing from intern...This study focuses on the climatic impacts of the Atlantic Multidecadal Oscillation （AMO） as a mode of internal vari- ability. Given the difficulties involved in excluding the effects of external forcing from internal variation, i.e., owing to the short record length of instrumental observations and historical simulations, we assess and compare the AMO and its related climatic impacts both in observations and in the ＂Pre-industrial＂ experiments of models participating in CMIP5. First, we evaluate the skill of the 25 CMIP5 models＇ ＂Historical＂ simulations in simulating the observational AMO, and find there is generally a considerable range of skill among them in this regard. Six of the models with higher skill relative to the other models are selected to investigate the AMO-related climate impacts, and it is found that their ＂Pre-industrial＂ simulations capture the essential features of the AMO. A positive AMO favors warmer surface temperature around the North Atlantic, and the Atlantic ITCZ shifts northward leading to more rainfall in the Sahel and less rainfall in Brazil. Furthermore, the results confirm the existence of a teleconnection between the AMO and East Asian surface temperature, as well as the late withdrawal of the Indian summer monsoon, during positive AMO phases. These connections could be mainly caused by internal climate variability. Opposite patterns are true for the negative phase of the AMO.展开更多
By adopting various stochastic weather generators, different research groups in their recent studies have realized the importance of the effects of climatic variability on crop growth and development. The conventional...By adopting various stochastic weather generators, different research groups in their recent studies have realized the importance of the effects of climatic variability on crop growth and development. The conventional assessments derived climate change scenarios from General Circulation Models (GCMs) experiments, however, are incapable of helping to understand this importance. The particular interest here is to review the general methodological scheme to incorporate stochastic weather generator into climate impact studies and the specific approaches in our studies, and put forward uncertainties that still exist. A variety of approaches have been taken to develop the parameterization program and stochastic experiment, and adjust the parameters of atypical stochastic weather generator called WGEN. Usually, the changes in monthly means and variances of weather variables between controlled and changed climate are used to perturb the parameters to generate the intended daily climate scenarios. We establish a parameterization program and methods for stochastic experiment of WGEN in the light of outputs of short-term climate prediction models, and evaluate its simulations on both temporal and spatial scales. Also, we manipulated parameters in relation to the changes in precipitation to produce the intended types and qualitative magnitudes of climatic variability. These adjustments yield various changes in climatic variability for sensitivity analyses. The impacts of changes in climatic variability on maize growth, final yield, and agro-climatic resources in Northeast China are assessed and presented as the case studies through the above methods. However, this corporation is still equivocal due to deficiencies of the generator and unsophisticated manipulation of parameters. To detect and simulate the changes in climatic variability is one of the indispensable ways to reduce the uncertainties in this aspect.展开更多
In the summers of 2003 and 2007, eastern China suffered similar climate disasters with severe flooding in the Huaihe River valley and heat waves in the southern Yangtze River delta and South China. Using SST data and ...In the summers of 2003 and 2007, eastern China suffered similar climate disasters with severe flooding in the Huaihe River valley and heat waves in the southern Yangtze River delta and South China. Using SST data and outgoing longwave radiation （OLR） data from NOAA along with reanalysis data from NCEP/NCAR, the 2002/03 and 2006/07 E1 Nifio episodes in the central Pacific and their delayed impacts on the following early summertime climate anomalies of eastern China were analyzed. The possible physical progresses behaved as follows： Both of the moderate E1 Ninio episodes matured in the central equatorial Pacific during the early winter. The zonal wind anomalies near the sea surface of the west-central equatorial Pacific excited equatorial Kelvin waves propagating eastward and affected the evolution of the E1 Nifio episodes. From spring to early summer, the concurring anomalous easterly winds in the central equatorial Pacific and the end of upwelling Kelvin waves propagating eastward in the western equatorial Pacific, favored the equatorial warm water both of the SST and the subsurface temperature in the western Pacific. These conditions favored the warm state of the western equatorial Pacific in the early summer for both cases of 2003 and 2007. Due to the active convection in the western equatorial Pacific in the early summer and the weak warm SST anomalies in the tropical western Pacific from spring to early summer, the convective activities in the western Pacific warm pool showed the pattern in which the anomalous strong convection only appeared over the southern regions of the tropical western Pacific warm pool, which effects the meridional shift of the western Pacific subtropical high in the summer. The physical progress of the delayed impacts of the E1 Nino episodes in the central equatorial Pacific and their decaying evolution on the climate anomalies in eastern China were interpreted through the key role of special pattern for the heat convection in the tropical western Pacific warm pool and the response of the western North Pacific anomalous anticyclone.展开更多
Daily and weekly reporting events of climate change and impacts on populations, cultures, economies and politics at local, national, regional and international scales suggest the need to construct databases that will ...Daily and weekly reporting events of climate change and impacts on populations, cultures, economies and politics at local, national, regional and international scales suggest the need to construct databases that will be useful in future scientific inquiry and global human/environmental policies. That need is evident in constructing a geographic or locational knowledge base that examines countries, regions and cities. This study constructs a database on the impacts of climate change using Google Scholar entries for 200 countries and capital cities. A series of maps reveal the vast unevenness in the database, especially between Global North and Global South countries. The discussion explores these sharp differences and suggests future research topics for much-needed global, interdisciplinary and international research.展开更多
The impacts of solar activity on climate are explored in this two-part study. Based on the principles of atmospheric dynamics, Part I propose an amplifying mechanism of solar impacts on winter climate extremes through...The impacts of solar activity on climate are explored in this two-part study. Based on the principles of atmospheric dynamics, Part I propose an amplifying mechanism of solar impacts on winter climate extremes through changing the atmospheric circulation patterns. This mechanism is supported by data analysis of the sunspot number up to the predicted Solar Cycle 24, the historical surface temperature data, and atmospheric variables of NCEP/NCAR Reanalysis up to the February 2011 for the Northern Hemisphere winters. For low solar activity, the thermal contrast between the low- and high-latitudes is enhanced, so as the mid-latitude baroclinic ultra-long wave activity. The land-ocean thermal contrast is also enhanced, which amplifies the topographic waves. The enhanced mid-latitude waves in turn enhance the meridional heat transport from the low to high latitudes, making the atmospheric ＂heat engine＂ more efficient than normal. The jets shift southward and the polar vortex is weakened. The Northern Annular Mode （NAM） index tends to be negative. The mid-latitude surface exhibits large-scale convergence and updrafts, which favor extreme weather/climate events to occur. The thermally driven Siberian high is enhanced, which enhances the East Asian winter monsoon （EAWM）. For high solar activity, the mid-latitude circulation patterns are less wavy with less meridional transport. The NAM tends to be positive, and the Siberian high and the EAWM tend to be weaker than normal. Thus the extreme weather/climate events for high solar activity occur in different regions with different severity from those for low solar activity. The solar influence on the mid- to high-latitude surface temperature and circulations can stand out after removing the influence from the E1 Nifio-Southern Oscillation. The atmospheric amplifying mechanism indicates that the solar impacts on climate should not be simply estimated by the magnitude of the change in the solar radiation over solar cycles when it is compared with other external radiative forcings that do not influence the climate in the same way as the sun does.展开更多
Based on climate change scenarios projected from GCMs (GFDL, UKMO and MPI), this study evaluates possible impacts of climate warming on rice production in China using numerical simulation experiments. A stochastic wea...Based on climate change scenarios projected from GCMs (GFDL, UKMO and MPI), this study evaluates possible impacts of climate warming on rice production in China using numerical simulation experiments. A stochastic weather generator is used to make the projected climatic change scenarios suitable to the input of crop model, ORYZA1. The results show that the duration of rice growing season will be lengthened by 6-11 days and the accumulated temperature will increase by 200℃.d-330℃.d when CO2 concentration in the atmosphere doubles. The probability of cool injury in reproductive and grain filling period will decrease while that of heat stress will increase. Rice yield will decrease if cultivars and fanning practices are unchanged. If the dates of rice development stages can be maintained unchanged through cultivar adjustment although rice yield in most parts of the areas will decrease, the decrements will be much less than that when cultivars and farming practices are unchanged.展开更多
Over 60% of Singapore＇s coral reefs have been lost to decades of coastal urbanization and heavy sedimentation has restricted coral development to the upper 5 m of the reef slope. High species diversity, predictable m...Over 60% of Singapore＇s coral reefs have been lost to decades of coastal urbanization and heavy sedimentation has restricted coral development to the upper 5 m of the reef slope. High species diversity, predictable mass spawning events and vigorous growth of larval recruits indicate that active rehabilitation can help enhance reef resilience to urbanization and climate change impacts. Rehabilitation techniques selected should address high sedimentation, destabilized reef substrate and reef community structure change. Coral species dominance has shifted to favor those more tolerant of reduced light. Initiating rehabilitation with these dominant species can stabilize the reef substrate quickly. Coral nurseries with raised mesh-net platforms prevent sediment smothering and improve survival of coral fragments and juveniles. Juveniles have also naturally recruited and developed on seawalls constructed in non-reef areas. Innovative design and engineering of coastal defenses can facilitate coral growth as sea level rises. Floating reefs and seawalls that incorporate terraced tidal pools can encourage continued growth and development of coral communities. Two approaches considered appropriate to rehabilitating coral communities exposed to impacts of urbanization and climate change are： （1） increase of live coral cover and diversity of degraded reefs; （2） creation of reef communities in non-reef areas.展开更多
Climate change in the Middle East area including Jordan has started to be reflected in decreasing precipitation and increasing temperatures with their impacts on the availability of surface and groundwater. This artic...Climate change in the Middle East area including Jordan has started to be reflected in decreasing precipitation and increasing temperatures with their impacts on the availability of surface and groundwater. This article aims to evaluate the impacts of decreasing or increasing precipitation by 10% and 20% on the quantities of flood runoff based on recorded precipitation and runoffs of catchments during the past 60 to 70 years of observation, during which the precipitation in individual or a few years increased or decreased by tens of percentages relative to the long-term average precipitation. The results of quantification show that in Jordan as a whole, decreasing precipitation by 10% and 20% has historically (during the recording period) resulted in reductions in flood flows by 26.2% and 52.8% and that increasing precipitation by 10% and 20% has resulted in increases in flood flows by 26.4% and 56.5% respectively. These results look somehow paradox, because the general perception is that flood runoff changes in the same percentage like precipitation although flood flow is not linearly correlated with precipitation but exponentially. Decreasing precipitation in the water-scarce stressed country, Jordan due to climatic changes, will have strong implications on rain-fed and irrigated agriculture and on household water supplies with very severe socio-economic percussions expressed in increasing unemployment and poverty which may lead to social and political unrest. Therefore, proactive measures have to be implemented before disasters hit. Such measures are limited in Jordan to seawater desalination, intensified water harvesting and improved water use efficiency in agriculture.展开更多
The emissions of greenhouse gasses in Egypt are about 0.58% of the total emissions of the world in the year 2015, although Egypt is one of the countries most affected by the impacts of climate change. By assessment an...The emissions of greenhouse gasses in Egypt are about 0.58% of the total emissions of the world in the year 2015, although Egypt is one of the countries most affected by the impacts of climate change. By assessment and analysis of the expected economic impacts of climate change by the year 2030, the Egyptian cultivated area will be reduced to about 0.949 million acres, equal to about 8.22% of the Egyptian cultivated area compared with the case of no sinking part of the Delta land, thus reducing crop area in Egypt to about 1.406 million acres, approximately to about 6.25% of crop area compared with the case of no sinking part of the Delta land, in addition to surplus in the Egyptian balance water to about 2.48 billion m3. In this case value of the Egyptian agriculture production will decrease by about 6.19 billion dollars, equal to about 6.19% compared with presumably no sinking of the Delta land. In the case of sinking 15% of Delta lands, with the change of the productivity and water consumption of most crops, the result will be a reduction in the cultivated area to about 0.94 million acres. In addition to decreasing the Egyptian crop area to about 1.39 million acres, with a deficit in the Egyptian balance water to about 4.74 billion m3 compared to the case of no sinking part of the Delta land, the cultivated area will decrease to about 8.17%, and the crop area will decrease 6.18%. Also, the value of the Egyptian agriculture production will decrease by about 12.51%. While compared to sinking part of the Delta land to about 15% of the total Delta area without the other impacts of climate change, the cultivated area will increase by about 0.06%;the crop area will increase by about 0.08%;also, the value of the Egyptian agriculture production will decrease by about 5.57%.展开更多
Global climate change is real and already taking place. The most recent Fifth Assessment Report of the Intergov- ernmental Panel on Climate Change （IPCC AR5） stated that global land and ocean surface temperature inc...Global climate change is real and already taking place. The most recent Fifth Assessment Report of the Intergov- ernmental Panel on Climate Change （IPCC AR5） stated that global land and ocean surface temperature increased by 0.85℃ over the period of 1880 to 2012 （IPCC Climate Change 2013）. China is among the most affected countries by global climate change.展开更多
Cotton is a revenue source for cotton-producing countries;as the second-largest crop in Pakistan,it significantly contributes to its economy.Over the past few decades,cotton productivity has become unstable in Pakista...Cotton is a revenue source for cotton-producing countries;as the second-largest crop in Pakistan,it significantly contributes to its economy.Over the past few decades,cotton productivity has become unstable in Pakistan,and climate change is one of the main factors that impact cotton yield.Due to climate change,it becomes very important to understand the change trend and its impact on cotton yield at the regional level.Here,we investigate the relationship of standardized cotton yield variability with the variability of climate factors using a 15-yr moving window.The piecewise regression was fitted to obtain the trend-shifting point of climate factors.The results show that precipitation has experienced an overall decreasing trend of–0.64 mm/yr during the study period,with opposing trends of–1.39 mm/yr and 1.52 mm/yr before and after the trend-shifting point,respectively.We found that cotton yield variability increased at a rate of 0.17%/yr,and this trend was highly correlated with the variability of climate factors.The multiple regression analysis explains that climate variability is a dominant factor and controlled 81%of the cotton production in the study area from 1990 to 2019,while it controlled 73%of the production from 1990 to 2002 and 84%from 2002 to 2019.These findings reveal that climate factors affact the distinct spatial pattern of changes in cotton yield variability at the tehsil level.展开更多
Climate Change is a global phenomenon that has a global scale impact. The current trend of climate change towards the warming of the globe has resulted in various changes in the geological, climatology, social, econom...Climate Change is a global phenomenon that has a global scale impact. The current trend of climate change towards the warming of the globe has resulted in various changes in the geological, climatology, social, economical, and bio-logical processes worldwide. Temperature of the globe has increased due to various factors, but anthropogenic plays a major contribution through the heavy input of Greenhouse gases. One of the world’s most remote regions that have been affected by most of the anthropogenic stresses on environmental services is the Arctic Region. The Arctic Region has shown various drastic changes and has shown to be effected by various anthropogenic activities that take place elsewhere. These changes include the ozone hole (resulting from ozone degrading compound emitted heavily by an-thropogenic demands), the accumulation of various persistent and volatile pollutants (i.e. POPs), and the meltdown of the polar ice (among others). These drastic changes are well perceived and well projected for future preparations. However, the question still remains if these impacts would only accelerate change. This paper aims to discuss if these changes are accelerating or happening at a constant rate. In addition, this paper aims to only focus on changes due to global warming and climate changes展开更多
The SST variation in the equatorial Indian Ocean is studied with special interest in analyzing its dipole oscillation feature. The dipole oscillation appears to be stronger in September-November and weaker in January-...The SST variation in the equatorial Indian Ocean is studied with special interest in analyzing its dipole oscillation feature. The dipole oscillation appears to be stronger in September-November and weaker in January-April with higher SST in the west region and lower SST in the east region as the positive phase and higher SST in the east region and lower SST in the west region as the negative phase. Generally, the amplitude of the positive phase is larger than the negative phase. The interannual variation (4-5 year period) and the interdecadal variation (25-30 year period) also exist in the dipole. The analyses also showed the significant impact of the Indian Ocean dipole on the Asian monsoon activity, because the lower tropospheric wind fields over the Southern Asia, the Tibetan high in the upper troposphere and the subtropical high over the northwestern Pacific are all related to the Indian Ocean dipole. On the other, the Indian Ocean dipole still has significant impact on atmospheric circulation and climate in North America and the southern Indian Ocean region (including Australia and South Africa).展开更多
The capability of an improved Dynamic Global Vegetation Model （DGVM） in reproducing the impact of climate on the terrestrial ecosystem is evaluated. The new model incorporates the Community Land Model- DGVM （CLM3.0...The capability of an improved Dynamic Global Vegetation Model （DGVM） in reproducing the impact of climate on the terrestrial ecosystem is evaluated. The new model incorporates the Community Land Model- DGVM （CLM3.0-DGVM） with a submodel for temperate and boreal shrubs, as well as other revisions such as the ＂two-leaf＂ scheme for photosynthesis and the definition of fractional coverage of plant functional types （PFTs）. Results show that the revised model may correctly reproduce the global distribution of temperate and boreal shrubs, and improves the model performance with more realistic distribution of di？erent vege- tation types. The revised model also correctly reproduces the zonal distributions of vegetation types. In reproducing the dependence of the vegetation distribution on climate conditions, the model shows that the dominant regions for trees, grasses, shrubs, and bare soil are clearly separated by a climate index derived from mean annual precipitation and temperature, in good agreement with the CLM4 surface data. The dominant plant functional type mapping to a two dimensional parameter space of mean annual temperature and precipitation also qualitatively agrees with the results from observations and theoretical ecology studies.展开更多
The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubl...The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubling CO2 climate. The wheat cultivation features and variety types may also assume significant changes. Climatic warming would have a positive influence in Northeast China, but high temperature stress may be produced in some regions of central and southern China. Higher mean air temperatures during wheat growth, particularly during the reproductive stages, may increase the need for earlier-maturing and more heat-tolerant cultivars.展开更多
Wind energy has been rapidly developed in China during the past decades and the installed capacity has been the largest in the world. In the future, utilization of wind power is still expected to carry out in China ma...Wind energy has been rapidly developed in China during the past decades and the installed capacity has been the largest in the world. In the future, utilization of wind power is still expected to carry out in China mainly with a large-scale centralized layout. Here, we examine the potential climatic impacts of large-scale windfarms associated with deployment scale in China using numerical experiments, in which four deployment scenarios were designed. These four scenarios represented relatively small- (484 GW), medium- (2165 GW) and large-scale (3490 GW and 5412 GW) installed wind power capacities, respectively. Results showed that turbulent kinetic energy, wind velocity, and air temperature varied consistently within those windfarms with the largest changes in turbine hub heights. Moreover, the above relatively large- scale windfarms could induce regional wanning with a maximum of above 0.8 °C in North China. This regional warming may be linked to an anomalous circulation pattern with a negative pressure anomaly center in Northeast China and a positive pressure anomaly center in the middle and lower reaches of the Yangtze-Huaihe River Basin.展开更多
Ecosystem of eastern Eurasian steppe is facing more and more challenges of global issues such as climate change, food and ecological security and human excessive utilization since the 21st century. Facing on the incre...Ecosystem of eastern Eurasian steppe is facing more and more challenges of global issues such as climate change, food and ecological security and human excessive utilization since the 21st century. Facing on the increasingly prominent international issues, it is very essential for relevant countries, international organizations and domestic counterparts to enhance systematic and mutual cooperation and exchanges to carry out scientific research and develop protection practice on the Eurasian steppe.展开更多
Climate change has major impacts directly on the natural ecosystem and human society, of which the cryosphere is most easily affected be-cause of its frangibility and sensitivity. Similarly, cryosphere change has nume...Climate change has major impacts directly on the natural ecosystem and human society, of which the cryosphere is most easily affected be-cause of its frangibility and sensitivity. Similarly, cryosphere change has numerous impacts on the natural ecosystem and human society, which may resemble an indirect influence of climate change. These two types of impacts, in shared fields, are distinguished in space and time by effective mechanisms and processes. Climate change has positive and negative impacts on some systems, which may be adjusted by cryosphere change. These indirect and direct impacts may be distinguished, and then correct policies and measures can be made against these changes.展开更多
This paper attempts to reveal a long-distance-relayed water vapor transport(LRWVT) east of Tibetan Plateau and its impacts. The results show that from August to October, east of Tibetan Plateau, there exists a unique ...This paper attempts to reveal a long-distance-relayed water vapor transport(LRWVT) east of Tibetan Plateau and its impacts. The results show that from August to October, east of Tibetan Plateau, there exists a unique LRWVT,and the water vapor from the South China Sea and the western Pacific can affect the Sichuan Basin, Northwest China and other Chinese regions far from the tropical sea through this way. From August to October, the precipitation of the region east of the Plateau is closely linked both in the intra-annual and inter-annual variations, and the LRWVT from the South China Sea and the western Pacific is an important connection mechanism. The large-scale circulation background of the LRWVT impacting the precipitation of the region east of the Plateau is as follows: At high levels,the South Asian High is generally stronger than normal and significantly enhances with its northward advance and eastward extension over the region east of the Plateau. At mid-level, a broad low pressure trough is over Lake Balkhash and its surroundings, and the Western Pacific Subtropical High(WPSH) is northward and westward located, and the western part of Sichuan Basin and the eastern part of Northwest China are located in the west and northwest edge of WPSH.展开更多
Detailed statistics of characteristics of climatic factors in Liaocheng in 2015 were carried out. The main points of meteorological service＇ were summed up to im- prove the ability of meteorological forecast, thereby...Detailed statistics of characteristics of climatic factors in Liaocheng in 2015 were carried out. The main points of meteorological service＇ were summed up to im- prove the ability of meteorological forecast, thereby meeting the new requirements of the public for meteorological cause. The results showed that the annual average temperature in various Counties was in the range of 13.6-14.5 ℃, which was slight- ly higher than that in an average year and lower than that in the past year; the average annual precipitation of various counties ranged from 376.9 to 592.1 mm, which was slightly less than those in an average year and the past year; the aver- age sunshine duration across the city was 2 026 h, which was less than that in an average year and slightly more than that in the past year. The main climatic events included fog and haze, heavy snowfall, thunderstorm, gale, hail, high temperature, heavy rain and rainy sparse sunlight, which produced a negative impact on the agri- culture, tourism, transportation and people＇s daily life. This is the focus of future services.展开更多
基金jointly supported by the National Natural Science Foundation of China(Grant No.41421004)the National Key Basic Research Development Program of China(Grant No.2016YFA0601802 and 2015CB453202)the National Natural Science Foundation of China(Grant Nos.41375085)
文摘This study focuses on the climatic impacts of the Atlantic Multidecadal Oscillation （AMO） as a mode of internal vari- ability. Given the difficulties involved in excluding the effects of external forcing from internal variation, i.e., owing to the short record length of instrumental observations and historical simulations, we assess and compare the AMO and its related climatic impacts both in observations and in the ＂Pre-industrial＂ experiments of models participating in CMIP5. First, we evaluate the skill of the 25 CMIP5 models＇ ＂Historical＂ simulations in simulating the observational AMO, and find there is generally a considerable range of skill among them in this regard. Six of the models with higher skill relative to the other models are selected to investigate the AMO-related climate impacts, and it is found that their ＂Pre-industrial＂ simulations capture the essential features of the AMO. A positive AMO favors warmer surface temperature around the North Atlantic, and the Atlantic ITCZ shifts northward leading to more rainfall in the Sahel and less rainfall in Brazil. Furthermore, the results confirm the existence of a teleconnection between the AMO and East Asian surface temperature, as well as the late withdrawal of the Indian summer monsoon, during positive AMO phases. These connections could be mainly caused by internal climate variability. Opposite patterns are true for the negative phase of the AMO.
基金This study was supported by the third sub-project of the national key research project in the 9thFive-Year Plan: Study on the
文摘By adopting various stochastic weather generators, different research groups in their recent studies have realized the importance of the effects of climatic variability on crop growth and development. The conventional assessments derived climate change scenarios from General Circulation Models (GCMs) experiments, however, are incapable of helping to understand this importance. The particular interest here is to review the general methodological scheme to incorporate stochastic weather generator into climate impact studies and the specific approaches in our studies, and put forward uncertainties that still exist. A variety of approaches have been taken to develop the parameterization program and stochastic experiment, and adjust the parameters of atypical stochastic weather generator called WGEN. Usually, the changes in monthly means and variances of weather variables between controlled and changed climate are used to perturb the parameters to generate the intended daily climate scenarios. We establish a parameterization program and methods for stochastic experiment of WGEN in the light of outputs of short-term climate prediction models, and evaluate its simulations on both temporal and spatial scales. Also, we manipulated parameters in relation to the changes in precipitation to produce the intended types and qualitative magnitudes of climatic variability. These adjustments yield various changes in climatic variability for sensitivity analyses. The impacts of changes in climatic variability on maize growth, final yield, and agro-climatic resources in Northeast China are assessed and presented as the case studies through the above methods. However, this corporation is still equivocal due to deficiencies of the generator and unsophisticated manipulation of parameters. To detect and simulate the changes in climatic variability is one of the indispensable ways to reduce the uncertainties in this aspect.
基金supported by the National Natural Science Foundation of China (No. 40705022)the "National Key Programme for Developing Basic Science" Project 2004CB418303the Frontier Project of the Knowledge Innovation Engineering of the Chinese Academy of Sciences(IAP07217)
文摘In the summers of 2003 and 2007, eastern China suffered similar climate disasters with severe flooding in the Huaihe River valley and heat waves in the southern Yangtze River delta and South China. Using SST data and outgoing longwave radiation （OLR） data from NOAA along with reanalysis data from NCEP/NCAR, the 2002/03 and 2006/07 E1 Nifio episodes in the central Pacific and their delayed impacts on the following early summertime climate anomalies of eastern China were analyzed. The possible physical progresses behaved as follows： Both of the moderate E1 Ninio episodes matured in the central equatorial Pacific during the early winter. The zonal wind anomalies near the sea surface of the west-central equatorial Pacific excited equatorial Kelvin waves propagating eastward and affected the evolution of the E1 Nifio episodes. From spring to early summer, the concurring anomalous easterly winds in the central equatorial Pacific and the end of upwelling Kelvin waves propagating eastward in the western equatorial Pacific, favored the equatorial warm water both of the SST and the subsurface temperature in the western Pacific. These conditions favored the warm state of the western equatorial Pacific in the early summer for both cases of 2003 and 2007. Due to the active convection in the western equatorial Pacific in the early summer and the weak warm SST anomalies in the tropical western Pacific from spring to early summer, the convective activities in the western Pacific warm pool showed the pattern in which the anomalous strong convection only appeared over the southern regions of the tropical western Pacific warm pool, which effects the meridional shift of the western Pacific subtropical high in the summer. The physical progress of the delayed impacts of the E1 Nino episodes in the central equatorial Pacific and their decaying evolution on the climate anomalies in eastern China were interpreted through the key role of special pattern for the heat convection in the tropical western Pacific warm pool and the response of the western North Pacific anomalous anticyclone.
文摘Daily and weekly reporting events of climate change and impacts on populations, cultures, economies and politics at local, national, regional and international scales suggest the need to construct databases that will be useful in future scientific inquiry and global human/environmental policies. That need is evident in constructing a geographic or locational knowledge base that examines countries, regions and cities. This study constructs a database on the impacts of climate change using Google Scholar entries for 200 countries and capital cities. A series of maps reveal the vast unevenness in the database, especially between Global North and Global South countries. The discussion explores these sharp differences and suggests future research topics for much-needed global, interdisciplinary and international research.
基金provided by the LASG State Key Laboratory Special Fund for this research project
文摘The impacts of solar activity on climate are explored in this two-part study. Based on the principles of atmospheric dynamics, Part I propose an amplifying mechanism of solar impacts on winter climate extremes through changing the atmospheric circulation patterns. This mechanism is supported by data analysis of the sunspot number up to the predicted Solar Cycle 24, the historical surface temperature data, and atmospheric variables of NCEP/NCAR Reanalysis up to the February 2011 for the Northern Hemisphere winters. For low solar activity, the thermal contrast between the low- and high-latitudes is enhanced, so as the mid-latitude baroclinic ultra-long wave activity. The land-ocean thermal contrast is also enhanced, which amplifies the topographic waves. The enhanced mid-latitude waves in turn enhance the meridional heat transport from the low to high latitudes, making the atmospheric ＂heat engine＂ more efficient than normal. The jets shift southward and the polar vortex is weakened. The Northern Annular Mode （NAM） index tends to be negative. The mid-latitude surface exhibits large-scale convergence and updrafts, which favor extreme weather/climate events to occur. The thermally driven Siberian high is enhanced, which enhances the East Asian winter monsoon （EAWM）. For high solar activity, the mid-latitude circulation patterns are less wavy with less meridional transport. The NAM tends to be positive, and the Siberian high and the EAWM tend to be weaker than normal. Thus the extreme weather/climate events for high solar activity occur in different regions with different severity from those for low solar activity. The solar influence on the mid- to high-latitude surface temperature and circulations can stand out after removing the influence from the E1 Nifio-Southern Oscillation. The atmospheric amplifying mechanism indicates that the solar impacts on climate should not be simply estimated by the magnitude of the change in the solar radiation over solar cycles when it is compared with other external radiative forcings that do not influence the climate in the same way as the sun does.
文摘Based on climate change scenarios projected from GCMs (GFDL, UKMO and MPI), this study evaluates possible impacts of climate warming on rice production in China using numerical simulation experiments. A stochastic weather generator is used to make the projected climatic change scenarios suitable to the input of crop model, ORYZA1. The results show that the duration of rice growing season will be lengthened by 6-11 days and the accumulated temperature will increase by 200℃.d-330℃.d when CO2 concentration in the atmosphere doubles. The probability of cool injury in reproductive and grain filling period will decrease while that of heat stress will increase. Rice yield will decrease if cultivars and fanning practices are unchanged. If the dates of rice development stages can be maintained unchanged through cultivar adjustment although rice yield in most parts of the areas will decrease, the decrements will be much less than that when cultivars and farming practices are unchanged.
文摘Over 60% of Singapore＇s coral reefs have been lost to decades of coastal urbanization and heavy sedimentation has restricted coral development to the upper 5 m of the reef slope. High species diversity, predictable mass spawning events and vigorous growth of larval recruits indicate that active rehabilitation can help enhance reef resilience to urbanization and climate change impacts. Rehabilitation techniques selected should address high sedimentation, destabilized reef substrate and reef community structure change. Coral species dominance has shifted to favor those more tolerant of reduced light. Initiating rehabilitation with these dominant species can stabilize the reef substrate quickly. Coral nurseries with raised mesh-net platforms prevent sediment smothering and improve survival of coral fragments and juveniles. Juveniles have also naturally recruited and developed on seawalls constructed in non-reef areas. Innovative design and engineering of coastal defenses can facilitate coral growth as sea level rises. Floating reefs and seawalls that incorporate terraced tidal pools can encourage continued growth and development of coral communities. Two approaches considered appropriate to rehabilitating coral communities exposed to impacts of urbanization and climate change are： （1） increase of live coral cover and diversity of degraded reefs; （2） creation of reef communities in non-reef areas.
文摘Climate change in the Middle East area including Jordan has started to be reflected in decreasing precipitation and increasing temperatures with their impacts on the availability of surface and groundwater. This article aims to evaluate the impacts of decreasing or increasing precipitation by 10% and 20% on the quantities of flood runoff based on recorded precipitation and runoffs of catchments during the past 60 to 70 years of observation, during which the precipitation in individual or a few years increased or decreased by tens of percentages relative to the long-term average precipitation. The results of quantification show that in Jordan as a whole, decreasing precipitation by 10% and 20% has historically (during the recording period) resulted in reductions in flood flows by 26.2% and 52.8% and that increasing precipitation by 10% and 20% has resulted in increases in flood flows by 26.4% and 56.5% respectively. These results look somehow paradox, because the general perception is that flood runoff changes in the same percentage like precipitation although flood flow is not linearly correlated with precipitation but exponentially. Decreasing precipitation in the water-scarce stressed country, Jordan due to climatic changes, will have strong implications on rain-fed and irrigated agriculture and on household water supplies with very severe socio-economic percussions expressed in increasing unemployment and poverty which may lead to social and political unrest. Therefore, proactive measures have to be implemented before disasters hit. Such measures are limited in Jordan to seawater desalination, intensified water harvesting and improved water use efficiency in agriculture.
文摘The emissions of greenhouse gasses in Egypt are about 0.58% of the total emissions of the world in the year 2015, although Egypt is one of the countries most affected by the impacts of climate change. By assessment and analysis of the expected economic impacts of climate change by the year 2030, the Egyptian cultivated area will be reduced to about 0.949 million acres, equal to about 8.22% of the Egyptian cultivated area compared with the case of no sinking part of the Delta land, thus reducing crop area in Egypt to about 1.406 million acres, approximately to about 6.25% of crop area compared with the case of no sinking part of the Delta land, in addition to surplus in the Egyptian balance water to about 2.48 billion m3. In this case value of the Egyptian agriculture production will decrease by about 6.19 billion dollars, equal to about 6.19% compared with presumably no sinking of the Delta land. In the case of sinking 15% of Delta lands, with the change of the productivity and water consumption of most crops, the result will be a reduction in the cultivated area to about 0.94 million acres. In addition to decreasing the Egyptian crop area to about 1.39 million acres, with a deficit in the Egyptian balance water to about 4.74 billion m3 compared to the case of no sinking part of the Delta land, the cultivated area will decrease to about 8.17%, and the crop area will decrease 6.18%. Also, the value of the Egyptian agriculture production will decrease by about 12.51%. While compared to sinking part of the Delta land to about 15% of the total Delta area without the other impacts of climate change, the cultivated area will increase by about 0.06%;the crop area will increase by about 0.08%;also, the value of the Egyptian agriculture production will decrease by about 5.57%.
文摘Global climate change is real and already taking place. The most recent Fifth Assessment Report of the Intergov- ernmental Panel on Climate Change （IPCC AR5） stated that global land and ocean surface temperature increased by 0.85℃ over the period of 1880 to 2012 （IPCC Climate Change 2013）. China is among the most affected countries by global climate change.
基金Under the auspices of National Key Research and Development Program of China (No.2017YFA0604403-3,2016YFA0602301)the Joint Fund of National Natural Science Foundation of China (No.U19A2023)。
文摘Cotton is a revenue source for cotton-producing countries;as the second-largest crop in Pakistan,it significantly contributes to its economy.Over the past few decades,cotton productivity has become unstable in Pakistan,and climate change is one of the main factors that impact cotton yield.Due to climate change,it becomes very important to understand the change trend and its impact on cotton yield at the regional level.Here,we investigate the relationship of standardized cotton yield variability with the variability of climate factors using a 15-yr moving window.The piecewise regression was fitted to obtain the trend-shifting point of climate factors.The results show that precipitation has experienced an overall decreasing trend of–0.64 mm/yr during the study period,with opposing trends of–1.39 mm/yr and 1.52 mm/yr before and after the trend-shifting point,respectively.We found that cotton yield variability increased at a rate of 0.17%/yr,and this trend was highly correlated with the variability of climate factors.The multiple regression analysis explains that climate variability is a dominant factor and controlled 81%of the cotton production in the study area from 1990 to 2019,while it controlled 73%of the production from 1990 to 2002 and 84%from 2002 to 2019.These findings reveal that climate factors affact the distinct spatial pattern of changes in cotton yield variability at the tehsil level.
文摘Climate Change is a global phenomenon that has a global scale impact. The current trend of climate change towards the warming of the globe has resulted in various changes in the geological, climatology, social, economical, and bio-logical processes worldwide. Temperature of the globe has increased due to various factors, but anthropogenic plays a major contribution through the heavy input of Greenhouse gases. One of the world’s most remote regions that have been affected by most of the anthropogenic stresses on environmental services is the Arctic Region. The Arctic Region has shown various drastic changes and has shown to be effected by various anthropogenic activities that take place elsewhere. These changes include the ozone hole (resulting from ozone degrading compound emitted heavily by an-thropogenic demands), the accumulation of various persistent and volatile pollutants (i.e. POPs), and the meltdown of the polar ice (among others). These drastic changes are well perceived and well projected for future preparations. However, the question still remains if these impacts would only accelerate change. This paper aims to discuss if these changes are accelerating or happening at a constant rate. In addition, this paper aims to only focus on changes due to global warming and climate changes
基金This work was supported by the National Key Basic Science Program in China (Grant No.1998040903) and Chinese NSF (Grant No 498
文摘The SST variation in the equatorial Indian Ocean is studied with special interest in analyzing its dipole oscillation feature. The dipole oscillation appears to be stronger in September-November and weaker in January-April with higher SST in the west region and lower SST in the east region as the positive phase and higher SST in the east region and lower SST in the west region as the negative phase. Generally, the amplitude of the positive phase is larger than the negative phase. The interannual variation (4-5 year period) and the interdecadal variation (25-30 year period) also exist in the dipole. The analyses also showed the significant impact of the Indian Ocean dipole on the Asian monsoon activity, because the lower tropospheric wind fields over the Southern Asia, the Tibetan high in the upper troposphere and the subtropical high over the northwestern Pacific are all related to the Indian Ocean dipole. On the other, the Indian Ocean dipole still has significant impact on atmospheric circulation and climate in North America and the southern Indian Ocean region (including Australia and South Africa).
基金supported by Chinese Academy of Sciences (KZCX2-YW-219, 100 Tal-ents Program)Ministry of Science and Technology of China (2009CB421406)
文摘The capability of an improved Dynamic Global Vegetation Model （DGVM） in reproducing the impact of climate on the terrestrial ecosystem is evaluated. The new model incorporates the Community Land Model- DGVM （CLM3.0-DGVM） with a submodel for temperate and boreal shrubs, as well as other revisions such as the ＂two-leaf＂ scheme for photosynthesis and the definition of fractional coverage of plant functional types （PFTs）. Results show that the revised model may correctly reproduce the global distribution of temperate and boreal shrubs, and improves the model performance with more realistic distribution of di？erent vege- tation types. The revised model also correctly reproduces the zonal distributions of vegetation types. In reproducing the dependence of the vegetation distribution on climate conditions, the model shows that the dominant regions for trees, grasses, shrubs, and bare soil are clearly separated by a climate index derived from mean annual precipitation and temperature, in good agreement with the CLM4 surface data. The dominant plant functional type mapping to a two dimensional parameter space of mean annual temperature and precipitation also qualitatively agrees with the results from observations and theoretical ecology studies.
文摘The potential CO2-induced impacts on the geographical shifts of wheat growth zones in China were studied from seven GCMs outputs. The wheat growth regions may move northward and westward under the condition of a doubling CO2 climate. The wheat cultivation features and variety types may also assume significant changes. Climatic warming would have a positive influence in Northeast China, but high temperature stress may be produced in some regions of central and southern China. Higher mean air temperatures during wheat growth, particularly during the reproductive stages, may increase the need for earlier-maturing and more heat-tolerant cultivars.
基金s We acknowledged the financial support of the National Key Research and Development Program of China (2018YFB1502803), the National Natural Science Foundation of China (41475066), and Tsinghua University Initiative Sci entific Research Program (20131089357, 20131089356).
文摘Wind energy has been rapidly developed in China during the past decades and the installed capacity has been the largest in the world. In the future, utilization of wind power is still expected to carry out in China mainly with a large-scale centralized layout. Here, we examine the potential climatic impacts of large-scale windfarms associated with deployment scale in China using numerical experiments, in which four deployment scenarios were designed. These four scenarios represented relatively small- (484 GW), medium- (2165 GW) and large-scale (3490 GW and 5412 GW) installed wind power capacities, respectively. Results showed that turbulent kinetic energy, wind velocity, and air temperature varied consistently within those windfarms with the largest changes in turbine hub heights. Moreover, the above relatively large- scale windfarms could induce regional wanning with a maximum of above 0.8 °C in North China. This regional warming may be linked to an anomalous circulation pattern with a negative pressure anomaly center in Northeast China and a positive pressure anomaly center in the middle and lower reaches of the Yangtze-Huaihe River Basin.
文摘Ecosystem of eastern Eurasian steppe is facing more and more challenges of global issues such as climate change, food and ecological security and human excessive utilization since the 21st century. Facing on the increasingly prominent international issues, it is very essential for relevant countries, international organizations and domestic counterparts to enhance systematic and mutual cooperation and exchanges to carry out scientific research and develop protection practice on the Eurasian steppe.
基金supported by the National Basic Research Program of China (No. 2007CB411507): "Cryospheric processes in China and their climatic, hydrologic and ecologic effects and adaptation"
文摘Climate change has major impacts directly on the natural ecosystem and human society, of which the cryosphere is most easily affected be-cause of its frangibility and sensitivity. Similarly, cryosphere change has numerous impacts on the natural ecosystem and human society, which may resemble an indirect influence of climate change. These two types of impacts, in shared fields, are distinguished in space and time by effective mechanisms and processes. Climate change has positive and negative impacts on some systems, which may be adjusted by cryosphere change. These indirect and direct impacts may be distinguished, and then correct policies and measures can be made against these changes.
基金Major Program of the National Natural Science Foundation of China(41290255)National Natural Science Foundation of China(41305082)Fundamental Research Funds of Chengdu Institute of Plateau Meteorology,CMA
文摘This paper attempts to reveal a long-distance-relayed water vapor transport(LRWVT) east of Tibetan Plateau and its impacts. The results show that from August to October, east of Tibetan Plateau, there exists a unique LRWVT,and the water vapor from the South China Sea and the western Pacific can affect the Sichuan Basin, Northwest China and other Chinese regions far from the tropical sea through this way. From August to October, the precipitation of the region east of the Plateau is closely linked both in the intra-annual and inter-annual variations, and the LRWVT from the South China Sea and the western Pacific is an important connection mechanism. The large-scale circulation background of the LRWVT impacting the precipitation of the region east of the Plateau is as follows: At high levels,the South Asian High is generally stronger than normal and significantly enhances with its northward advance and eastward extension over the region east of the Plateau. At mid-level, a broad low pressure trough is over Lake Balkhash and its surroundings, and the Western Pacific Subtropical High(WPSH) is northward and westward located, and the western part of Sichuan Basin and the eastern part of Northwest China are located in the west and northwest edge of WPSH.
基金Supported by Trial on Change Rules of CO_2 in Solar Greenhouse and Its Effect on Tomato(2015sdqxm10)~~
文摘Detailed statistics of characteristics of climatic factors in Liaocheng in 2015 were carried out. The main points of meteorological service＇ were summed up to im- prove the ability of meteorological forecast, thereby meeting the new requirements of the public for meteorological cause. The results showed that the annual average temperature in various Counties was in the range of 13.6-14.5 ℃, which was slight- ly higher than that in an average year and lower than that in the past year; the average annual precipitation of various counties ranged from 376.9 to 592.1 mm, which was slightly less than those in an average year and the past year; the aver- age sunshine duration across the city was 2 026 h, which was less than that in an average year and slightly more than that in the past year. The main climatic events included fog and haze, heavy snowfall, thunderstorm, gale, hail, high temperature, heavy rain and rainy sparse sunlight, which produced a negative impact on the agri- culture, tourism, transportation and people＇s daily life. This is the focus of future services.
