This study aims to evaluate the development of soil reaction values in 15 key localities of soil Partial Monitoring System from 1994 to 2023, and to identify the most important regional drivers of pH value development...This study aims to evaluate the development of soil reaction values in 15 key localities of soil Partial Monitoring System from 1994 to 2023, and to identify the most important regional drivers of pH value development. Soil samples were collected from the depth 0 - 0.10 m yearly in the spring (5 samples from each locality). In the dry soil, samples were determined actively and exchanged soil reaction. The most significant negative changes (decreases of soil reaction) were determined in Haplic Stagnosols group and Cambisols group. The pH value in topsoil is primarily controlled by soil type and soil substrate, soil management and land use, and to a lesser extent by climatic region.展开更多
The regional climate model (RegCM3) and a tropospheric atmosphere chemistry model (TACM) were coupled, thus a regional climate chemistry modeling system (RegCCMS) was constructed, which was applied to investigat...The regional climate model (RegCM3) and a tropospheric atmosphere chemistry model (TACM) were coupled, thus a regional climate chemistry modeling system (RegCCMS) was constructed, which was applied to investigate the spatial distribution of anthropogenic nitrate aerosols, indirect radiative forcing, as well as its climatic effect over China. TACM includes the thermodynamic equilibrium model ISORROPIA and a condensed gas-phase chemistry model. Investigations show that the concentration of nitrate aerosols is relatively high over North and East China with a maximum of 29μg m-3 in January and 8 μg m-3 in July. Due to the influence of air temperature on thermodynamic equilibrium, wet scavenging of precipitation and the monsoon climate, there are obvious seasonal differences in nitrate concentrations. The average indirect radiative forcing at the tropopause due to nitrate aerosols is -1.63 W m 2 in January and -2.65 W m 2 in July, respectively. In some areas, indirect radiative forcing reaches -10 W m-2. Sensitivity tests show that nitrate aerosols make the surface air temperature drop and the precipitation reduce on the national level. The mean changes in surface air temperature and precipitation are 0.13 K and -0.01 mm d-1 in January and -0.09 K and -0.11 mm d-1 in July, respectively, showing significant differences in different regions.展开更多
The regional climate model RegCM4 was used to investigate the regional climate effects of land cover change over China. Two 24-year simulations (1978-2001), one with the land cover derived from the MODIS data and th...The regional climate model RegCM4 was used to investigate the regional climate effects of land cover change over China. Two 24-year simulations (1978-2001), one with the land cover derived from the MODIS data and the other with the CLCV (Chinese land cover derived from vegetation map) data, were conducted for a region encompassing China. The differences between the MODIS and CLCV data reflect characteristics of desertification and degradation of vegetation in China. Results indicate that the land cover change has important impacts on local climate through mechanisms related to changes in surface energy, water budgets and macro-scale circulation. In summer, the land cover change leads to a decrease in surface air temperature over southern China, a reduction in precipitation and an increase in surface air temperature in the transitional climate zone and the northern Tibetan Plateau, and an increase in inter-annual variability of surface air temperature in the marginal monsoon zone and northwestern China. Strengthened southwesterly winds increase precipitation to some extent in central and eastern Inner Mongolia by enhancing water vapor transport. In winter, enhanced northerly winds, bringing more dry and cold air, lead to a reduction in precipitation and temperature over areas south of the Yellow River.展开更多
The authors used a high-resolution regional climate model (RegCM3) coupled with a chemistry/ aerosol module to simulate East Asian climate in 2006 and to test the climatic impacts of aerosols on regional- scale clim...The authors used a high-resolution regional climate model (RegCM3) coupled with a chemistry/ aerosol module to simulate East Asian climate in 2006 and to test the climatic impacts of aerosols on regional- scale climate. The direct radiative forcing and climatic effects of aerosols (dust, sulfate, black carbon, and organic carbon) were discussed. The results indicated that aerosols generally produced negative radiative forcing at the top-of-the-atmosphere (TOA) over most areas of East Asia. The radiative forcing induced by aerosols exhibited significant seasonal and regional variations, with the strongest forcing occurring in summer. The aerosol feed- backs on surface air temperature and precipitation were clear. Surface cooling dominated features over the East Asian continental areas, which varied in the approximate range of-0.5 to -2℃ with the maximum up to -3℃ in summer over the deserts of West China. The aerosols induced complicated variations of precipitation. Except in summer, the rainfall generally varied in the range of-1 to 1 mm d^-1 over most areas of China.展开更多
【Title】There are knowledge gaps in our understanding of vegetation responses to multi-scale climate-related variables in tropical/subtropical mountainous islands in the Asia-Pacific region. Therefore, this study inv...【Title】There are knowledge gaps in our understanding of vegetation responses to multi-scale climate-related variables in tropical/subtropical mountainous islands in the Asia-Pacific region. Therefore, this study investigated inter-annual vegetation dynamics and regular/irregular climate patterns in Taiwan. We applied principal component analysis (PCA) on 11 years (2001~2011) of high-dimensional monthly photosynthetically active vegetation cover (PV) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and investigated the relationships between spatiotemporal patterns of the eigenvectors and loadings of each component through time and multi-scale climate-related variations. Results showed that the first five components contributed to 96.4% of the total variance. The first component (PC1, explaining 94.5% of variance) loadings, as expected, were significantly correlated with the temporal dynamics of the PV (r = 0.94), which was mainly governed by regional climate. The temporal loadings of PC2 and PC3 (0.8% and 0.6% of variance, respectively) were significantly correlated with the temporal dynamics of the PV of forests (r = 0.72) and the farmlands (r = 0.80), respectively. The low-order components (PC4 and PC5, 0.3% and 0.2% of variance, respectively) were closely related to the occurrence of drought (r = 0.49) and to irregular ENSO associated climate anomalies (r = -0.54), respectively. Pronounced correlations were also observed between PC5 and the Southern Oscillation Index (SOI) with one to three months of time lags (r = -0.35 ~ -0.43, respectively), revealing biophysical memory effects on the time-series pattern of the vegetation through ENSO-related rainfall patterns. Our findings reveal that the sensitivity of the ecosystems in this tropical/subtropical mountainous island may not only be regulated by regional climate and human activities but also be susceptible to large-scale climate anomalies which are crucial and comparable to previous large scale analyses. This study demonstrates that PCA can be an effective tool for analyzing seasonal and inter-annual variability of vegetation dynamics across this tropical/subtropical mountainous islandin the Pacific Ocean, which provides an opportunity to forecast the responses and feedbacks of terrestrial environments to future climate scenarios.展开更多
This study presents a dynamically downscaled climatology over East Asia using the non-hydrostatic Weather Research and Forecasting (WRF) model, forced by the Twentieth Century Reanalysis (20CR-v2). The whole exper...This study presents a dynamically downscaled climatology over East Asia using the non-hydrostatic Weather Research and Forecasting (WRF) model, forced by the Twentieth Century Reanalysis (20CR-v2). The whole experiment is a 111-year (1900--2010) continuous run at 50 km horizontal resolution. Comparisons of climatic means and seasonal cycles among observations, 20CR-v2, and WRF results during the last 30 years (1981-2010) in China are presented, with a focus on sur- face air temperature and precipitation in both summer and winter. The WRF results reproduce the main features of surface air temperature in the two seasons in China, and outperform 20CR-v2 in regional details due to topog- raphic forcing. Summer surface air temperature biases are reduced by as much as 1℃-2℃. For precipitation, the simulation results reproduce the decreasing pattern from Southeast to Northwest China in winter. For summer rainfall, the WRF simulation results reproduce the correct magnitude and position of heavy rainfall around the southeastern coastal area, and are better than 20CR-v2. One of the significant improvements is that an unrealistic center of summer precipitation in Southeast China present in 20CR-v2 is eliminated. However, the simulated results underestimate winter surface air temperature in northern China and winter rainfall in some regions in southeastern China. The mean seasonal cycles of surface air tempera- ture and precipitation are captured well over most of sub-regions by the WRF model.展开更多
The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air te...The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air temperatureand decreased by 5% in annual precipitation over 1951-1990. Regionally, temperature change has varied from acooling of 0.3℃ in Southwest China to a'warming of 1 .0℃ in Northeast China. With the exception of South China,all regions of China have shown a declination in precipitation. Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation. Under doubled CO2 concentration,climatic change in China will tend to be warmer and moister, with increases of 4.5℃ in annual mean air temperatureand 11% in annual precipitation on the national scale. Future climatic change will reduce the temporal and spatialdifferences of climatic factors.展开更多
[Objectives]This study was conducted to scientifically plan orange osmanthus planting in Pucheng County to promote the development of agricultural economy.[Methods]Two factors,the total number of days with daily avera...[Objectives]This study was conducted to scientifically plan orange osmanthus planting in Pucheng County to promote the development of agricultural economy.[Methods]Two factors,the total number of days with daily average temperature≥15℃from March to August and the total number of days with daily average temperature≥20℃in September were determined as the regionalization index factors using the weather data and geographic information data of Pucheng County,according to the 80%guarantee rate principle,the mean square error method and the actual growth law of orange osmanthus.Then,according to the weighted stack method,comprehensively considering the on-site inspection results and expert opinions,the suitability of orange osmanthus planting layout in Pucheng County was evaluated,and the GIS spatial interpolation technology was applied to complete the refined agroclimatic regionalization.[Results]The growth of Pucheng orange osmanthus has a great relationship with the thermal conditions,and it is clear that the suitable,sub-suitable and unsuitable areas for orange osmanthus planting in Pucheng County have certain applicability and maneuverability.[Conclusions]This study will play a scientific guiding role in the industrialization and development of orange osmanthus planting in Pucheng County.展开更多
The different spatial distributions of aerosol-induced direct radiative forcing and climatic effects in a weak (2003) and a strong (2006) East Asian summer monsoon (EASM) circulation were simulated using a high-...The different spatial distributions of aerosol-induced direct radiative forcing and climatic effects in a weak (2003) and a strong (2006) East Asian summer monsoon (EASM) circulation were simulated using a high-resolution regional climate model (RegCM3).Results showed that the atmospheric circulations of summer monsoon have direct relations with transport of aerosols and their climatic effects.Both the top-of-the-atmosphere (TOA) and the surface-negative radiative forcing of aerosols were stronger in weak EASM circulations.The main difference in aerosol-induced negative forcing in two summers varied between 2 and 14 W m-2 from the Sichuan Basin to North China,where a maximum in aerosol-induced negative forcing was also noticed in the EASM-dominated areas.The spatial difference in the simulated aerosol optical depth (AOD) in two summers generally showed the similar pictures.Surface cooling effects induced by aerosols were spatially more uniform in weak EASM circulations and cooler by about 1-4.5℃.A preliminary analysis here indicated that a weaker low-level wind speed not conducive to the transport and diffusion of aerosols could make more contributions to the differences in the two circulations.展开更多
Climate change significantly impacts forest ecosystems in arid and semi-arid regions.However,spatiotemporal patterns of climate-sensitive changes in individual tree growth under increased climate warming and precipita...Climate change significantly impacts forest ecosystems in arid and semi-arid regions.However,spatiotemporal patterns of climate-sensitive changes in individual tree growth under increased climate warming and precipitation in north-west China is unclear.The dendrochronological method was used to study climate response sensitivity of radial growth of Picea schrenkiana from 158 trees at six sites during 1990-2020.The results show that climate warming and increased precipitation significantly promoted the growth of trees.The response to temperature first increased,then decreased.However,the response to increased precipitation and the self-calibrating Palmer Drought Severity Index(scPDSI)increased significantly.In most areas of the Tianshan Mountains,the proportion of trees under increased precipitation and scPDSI positive response was relatively high.Over time,small-diameter trees were strongly affected by drought stress.It is predicted that under continuous warming and increased precipitation,trees in most areas of the Tianshan Mountains,especially those with small diameters,will be more affected by precipitation.展开更多
Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration a...Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world.展开更多
The influences of human activity on regional climate over China have been widely reported and drawn great attention from both the scientific community and governments.This paper reviews the evidence of the anthropogen...The influences of human activity on regional climate over China have been widely reported and drawn great attention from both the scientific community and governments.This paper reviews the evidence of the anthropogenic influence on regional climate over China from the perspectives of surface air temperature(SAT),precipitation,droughts,and surface wind speed,based on studies published since 2018.The reviewed evidence indicates that human activities,including greenhouse gas and anthropogenic aerosol emissions,land use and cover change,urbanization,and anthropogenic heat release,have contributed to changes in the SAT trend and the likelihood of regional record-breaking extreme high/low temperature events over China.The anthropogenically forced SAT signal can be detected back to the 1870s in the southeastern Tibetan Plateau region.Although the anthropogenic signal of summer precipitation over China is detectable and anthropogenic forcing has contributed to an increased likelihood of regional record-breaking heavy/low precipitation events,the anthropogenic precipitation signal over China is relatively obscure.Moreover,human activities have also contributed to a decline in surface wind speed,weakening of monsoon precipitation,and an increase in the frequency of droughts and compound extreme climate/weather events over China in recent decades.This review can serve as a reference both for further understanding the causes of regional climate changes over China and for sound decision-making on regional climate mitigation and adaptation.Additionally,a few key or challenging scientific issues associated with the human influence on regional climate changes are discussed in the context of future research.展开更多
Human activities have notably affected the Earth’s climate through greenhouse gases(GHG), aerosol, and land use/land cover change(LULCC). To investigate the impact of forest changes on regional climate under differen...Human activities have notably affected the Earth’s climate through greenhouse gases(GHG), aerosol, and land use/land cover change(LULCC). To investigate the impact of forest changes on regional climate under different shared socioeconomic pathways(SSPs), changes in surface air temperature and precipitation over China under low and medium/high radiative forcing scenarios from 2021 to 2099 are analyzed using multimodel climate simulations from the Coupled Model Intercomparison Project Phase 6(CMIP6). Results show that the climate responses to forest changes are more significant under the low radiative forcing scenario. Deforestation would increase the mean, interannual variability, and the trend of surface air temperature under the low radiative forcing scenario, but it would decrease those indices under the medium/high radiative forcing scenario. The changes in temperature show significant spatial heterogeneity. For precipitation, under the low radiative forcing scenario, deforestation would lead to a significant increase in northern China and a significant decrease in southern China, and the effects are persistent in the near term(2021–40), middle term(2041–70), and long term(2071–99). In contrast, under the medium/high radiative forcing scenario, precipitation increases in the near term and long term over most parts of China, but it decreases in the middle term, especially in southern, northern,and northeast China. The magnitude of precipitation response to deforestation remains comparatively small.展开更多
Based on the meteorological data and DEM data in the producing areas of Morchella esculenta in the western Sichuan plateau from 1991 to 2020, the biological characteristics of M. esculenta, as well as the survey of pr...Based on the meteorological data and DEM data in the producing areas of Morchella esculenta in the western Sichuan plateau from 1991 to 2020, the biological characteristics of M. esculenta, as well as the survey of production in the planting area, the correlation between M. esculenta production and the climatic ecological conditions at an altitude of 1 200-3 000 m in the western Sichuan plateau was comprehensively analyzed by using the inverse distance weight method, analytic hierarchy process, climate risk assessment model and geographic information system(GIS), and restrictive or high impact climatic ecological factors were selected as the suitability zoning indicators to carry out the analysis of climatic ecological suitability and planting zoning. The results show that the climatic factors affecting M. esculenta cultivation in the western Sichuan plateau were mainly temperature, temperature difference between day and night, and humidity, and the main meteorological disaster was freezing disaster. Under the influence of vertical changes in temperature, topography and cold damage, the growing areas of M. esculenta in the western Sichuan plateau were mainly distributed in the Minjiang River basin and the river valley along the Dadu River basin at an altitude of 1 200-2 000 m, and were distributed in strips and branches along the rivers. The suitable areas were mainly distributed in Wenchuan, Lixian, Maoxian, Kangding, Jiulong and Luding counties(cities), which were the main producing areas of M. esculenta, but the area was small, accounting for only 3.5% of the study area;the sub-suitable areas were mainly distributed in some towns of Danba, Xiaojin, Wenchuan, Lixian, Maoxian, Heishui and Jiuzhaigou counties, accounting for 36.0% of the total area, and they were the main planting areas of M. esculenta.展开更多
Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation planning.Previous related studies mainly focused...Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation planning.Previous related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate models.Here,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation effects.Two experiments were conducted with and without winter wheat irrigation to isolate the effects of irrigation.Results showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil moisture.Moreover,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation schemes.Winter wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum temperature.Additionally,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the atmosphere.Further analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and agriculture.Fortunately,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated region.Additionally,no notable change was found in terms of heavy rainfall events and precipitation intensity,which might be an undereastimation caused by the less water use in model simulation.Although winter wheat irrigation does not have notable impact on the climate of the surrounding region,it is an important factor for the local-scale climate.展开更多
[Objective] The aim was to make full use of light-heat resources to expand the potato planting area on the base of ensuring the production of main grain crops and the limited arable land. [Methods] Through catch crops...[Objective] The aim was to make full use of light-heat resources to expand the potato planting area on the base of ensuring the production of main grain crops and the limited arable land. [Methods] Through catch crops, multiple cropping and intercropping, new multiple planting patterns of potato with efficiency are constructed, for the purpose of increasing yield and benefit of potato. [Result] In irrigated plain and hill area, three new planting patterns such as autumn potato/rope-rice,winter potato-rice-autumn potato, and autumn(winter) potato-rice were constructed.In dry land of plain and hill area, three new planting patterns such as spring(winter)potato/maize/sweet potato, spring(winter) potato/maize-autumn potato, and wheat + winter potato/maize/sweet potato were constructed. In plateau mountainous area, spring potato/maize was constructed. [Conclusion] With use of new planting patterns, the cropping index of new patterns was 200%-300%, while the accumulated temperature utilization was 68.9%-93.4%, light energy utilization was 0.98%-1.59% and straw utilization was 50%-100%. To compared with traditional planting patterns, the yield increased by 2.6%-93%, and benefit increased by 15.8%-284.3%. Furthermore,multiple planting patterns of potato have become main planting patterns in increasing yield and income in Sichuan.展开更多
This paper describes the construction of a 0.5°× 0.5° daily temperature dataset for the period of 1961- 2005 over China's Mainland for the purpose of climate model validation. The dataset is based o...This paper describes the construction of a 0.5°× 0.5° daily temperature dataset for the period of 1961- 2005 over China's Mainland for the purpose of climate model validation. The dataset is based on the interpolation from 751 observing stations in China and comprises 3 variables: daily mean, minimum, and maximum temperature. The "anomaly approach" is applied in the interpolation. The gridded climatology of 1971-2000 is first calculated and then a gridded daily anomaly for 1961-2005 is added to the climatology to obtain the final dataset. Comparison of the dataset with CRU (Climatic Research Unit) observations at the monthly scale shows general agreement between the two datasets. The differences found can be largely attributed to the introduction of observations at new stations. The dataset shows similar interannual variability as does CRU data over North China and eastern part of the Tibetan Plateau, but with a slightly larger linear trend. The dataset is employed to validate the simulation of three extreme indices based on daily mean, minimum, and maximum temperature by a high-resolution regional climate model. Results show that the model reproduces these indices well. The data are available at the National Climate Center of China Meteorological Administration, and a coarser resolution (1°× 1°) version can be accessed via the World Wide Web.展开更多
Changes of extreme events due to greenhouse effects (2 × CO<SUB>2</SUB>) over East Asia, with a focus on the China region as simulated by a regional climate model (RegCM2), are investigated. The model...Changes of extreme events due to greenhouse effects (2 × CO<SUB>2</SUB>) over East Asia, with a focus on the China region as simulated by a regional climate model (RegCM2), are investigated. The model is nested to a global coupled ocean-atmosphere model (CSIRO R21L9 AOGCM). Analysis of the control run of the regional model indicates that it can reproduce well the extreme events in China. Statistically significant changes of the events are analyzed. Results show that both daily maximum and daily minimum temperature increase in 2 × CO<SUB>2</SUB> conditions, while the diurnal temperature range decreases. The number of hot spell days increases while the number of cold spell days decreases. The number of rainy days and heavy rain days increases over some sub-regions of China. The 2 × CO<SUB>2</SUB> conditions also cause some changes in the tropical storms affecting China.展开更多
Climate effects of land use change in China as simulated by a regional climate model (RegCM2) are investigated. The model is nested in one-way mode within a global coupled atmosphere-ocean model (CSIRO R21L9 AOGCM). T...Climate effects of land use change in China as simulated by a regional climate model (RegCM2) are investigated. The model is nested in one-way mode within a global coupled atmosphere-ocean model (CSIRO R21L9 AOGCM). Two multi-year simulations, one with current land use and the other with potential vegetation cover, are conducted. Statistically significant changes of precipitation, surface air temperature, and daily maximum and daily minimum temperature are analyzed based on the difference between the two simulations. The simulated effects of land use change over China include a decrease of mean annual precipitation over Northwest China, a region with a prevalence of arid and semi-arid areas; an increase of mean annual surface air temperature over some areas; and a decrease of temperature along coastal areas. Summer mean daily maximum temperature increases in many locations, while winter mean daily minimum temperature decreases in East China and increases in Northwest China. The upper soil moisture decreases significantly across China. The results indicate that the same land use change may cause different climate effects in different regions depending on the surrounding environment and climate characteristics.展开更多
Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission sce...Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission scenarios of the Representative Concentration Pathways—RCP4.5 and RCP8.5.This is based on a period of transient simulations from 1950 to2099,with a grid spacing of 50 km.The present paper focuses on the annual mean temperature and precipitation in China over this period,with emphasis on their future changes.Validation of model performance reveals marked improvement of the RegCM4.0 model in reproducing present day temperature and precipitation relative to the driving BCC_CSM1.1 model.Significant warming is simulated by both BCC_CSM1.1 and RegCM4.0,however,spatial distribution and magnitude differ between the simulations.The high emission scenario RCP8.5 results in greater warming compared to RCP4.5.The two models project different precipitation changes,characterized by a general increase in the BCC_CSM1.1,and broader areas with decrease in the RegCM4.0 simulations.展开更多
文摘This study aims to evaluate the development of soil reaction values in 15 key localities of soil Partial Monitoring System from 1994 to 2023, and to identify the most important regional drivers of pH value development. Soil samples were collected from the depth 0 - 0.10 m yearly in the spring (5 samples from each locality). In the dry soil, samples were determined actively and exchanged soil reaction. The most significant negative changes (decreases of soil reaction) were determined in Haplic Stagnosols group and Cambisols group. The pH value in topsoil is primarily controlled by soil type and soil substrate, soil management and land use, and to a lesser extent by climatic region.
基金supported by the National Basic Research Program of China (Grant Nos. 2006CB403706 and 2006CB403703)the National Science and Technology Support Program (Grant No.2007BAC03A01)the Jiangsu Natural Science Foundation (Grant No. BK2006515)
文摘The regional climate model (RegCM3) and a tropospheric atmosphere chemistry model (TACM) were coupled, thus a regional climate chemistry modeling system (RegCCMS) was constructed, which was applied to investigate the spatial distribution of anthropogenic nitrate aerosols, indirect radiative forcing, as well as its climatic effect over China. TACM includes the thermodynamic equilibrium model ISORROPIA and a condensed gas-phase chemistry model. Investigations show that the concentration of nitrate aerosols is relatively high over North and East China with a maximum of 29μg m-3 in January and 8 μg m-3 in July. Due to the influence of air temperature on thermodynamic equilibrium, wet scavenging of precipitation and the monsoon climate, there are obvious seasonal differences in nitrate concentrations. The average indirect radiative forcing at the tropopause due to nitrate aerosols is -1.63 W m 2 in January and -2.65 W m 2 in July, respectively. In some areas, indirect radiative forcing reaches -10 W m-2. Sensitivity tests show that nitrate aerosols make the surface air temperature drop and the precipitation reduce on the national level. The mean changes in surface air temperature and precipitation are 0.13 K and -0.01 mm d-1 in January and -0.09 K and -0.11 mm d-1 in July, respectively, showing significant differences in different regions.
基金supported by the National Basic Research Program (No.2010CB428403, 2010CB951001)the National Natural Science Foundation of China (No.91125016)
文摘The regional climate model RegCM4 was used to investigate the regional climate effects of land cover change over China. Two 24-year simulations (1978-2001), one with the land cover derived from the MODIS data and the other with the CLCV (Chinese land cover derived from vegetation map) data, were conducted for a region encompassing China. The differences between the MODIS and CLCV data reflect characteristics of desertification and degradation of vegetation in China. Results indicate that the land cover change has important impacts on local climate through mechanisms related to changes in surface energy, water budgets and macro-scale circulation. In summer, the land cover change leads to a decrease in surface air temperature over southern China, a reduction in precipitation and an increase in surface air temperature in the transitional climate zone and the northern Tibetan Plateau, and an increase in inter-annual variability of surface air temperature in the marginal monsoon zone and northwestern China. Strengthened southwesterly winds increase precipitation to some extent in central and eastern Inner Mongolia by enhancing water vapor transport. In winter, enhanced northerly winds, bringing more dry and cold air, lead to a reduction in precipitation and temperature over areas south of the Yellow River.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-Q11-03)the National Basic Research Program of China(2009CB421407)the National Natural Science Foundation of China(40805030)
文摘The authors used a high-resolution regional climate model (RegCM3) coupled with a chemistry/ aerosol module to simulate East Asian climate in 2006 and to test the climatic impacts of aerosols on regional- scale climate. The direct radiative forcing and climatic effects of aerosols (dust, sulfate, black carbon, and organic carbon) were discussed. The results indicated that aerosols generally produced negative radiative forcing at the top-of-the-atmosphere (TOA) over most areas of East Asia. The radiative forcing induced by aerosols exhibited significant seasonal and regional variations, with the strongest forcing occurring in summer. The aerosol feed- backs on surface air temperature and precipitation were clear. Surface cooling dominated features over the East Asian continental areas, which varied in the approximate range of-0.5 to -2℃ with the maximum up to -3℃ in summer over the deserts of West China. The aerosols induced complicated variations of precipitation. Except in summer, the rainfall generally varied in the range of-1 to 1 mm d^-1 over most areas of China.
基金sponsored by the grants of the National Science Council of Taiwan(NSC 98-2221E-002-198-,NSC 98-2313-B-002-062-MY2,NSC 100-2621-B-002-001-MY3)National Taiwan University(EcoNTU:NTU-CESRP-102R7604-2)
文摘【Title】There are knowledge gaps in our understanding of vegetation responses to multi-scale climate-related variables in tropical/subtropical mountainous islands in the Asia-Pacific region. Therefore, this study investigated inter-annual vegetation dynamics and regular/irregular climate patterns in Taiwan. We applied principal component analysis (PCA) on 11 years (2001~2011) of high-dimensional monthly photosynthetically active vegetation cover (PV) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and investigated the relationships between spatiotemporal patterns of the eigenvectors and loadings of each component through time and multi-scale climate-related variations. Results showed that the first five components contributed to 96.4% of the total variance. The first component (PC1, explaining 94.5% of variance) loadings, as expected, were significantly correlated with the temporal dynamics of the PV (r = 0.94), which was mainly governed by regional climate. The temporal loadings of PC2 and PC3 (0.8% and 0.6% of variance, respectively) were significantly correlated with the temporal dynamics of the PV of forests (r = 0.72) and the farmlands (r = 0.80), respectively. The low-order components (PC4 and PC5, 0.3% and 0.2% of variance, respectively) were closely related to the occurrence of drought (r = 0.49) and to irregular ENSO associated climate anomalies (r = -0.54), respectively. Pronounced correlations were also observed between PC5 and the Southern Oscillation Index (SOI) with one to three months of time lags (r = -0.35 ~ -0.43, respectively), revealing biophysical memory effects on the time-series pattern of the vegetation through ENSO-related rainfall patterns. Our findings reveal that the sensitivity of the ecosystems in this tropical/subtropical mountainous island may not only be regulated by regional climate and human activities but also be susceptible to large-scale climate anomalies which are crucial and comparable to previous large scale analyses. This study demonstrates that PCA can be an effective tool for analyzing seasonal and inter-annual variability of vegetation dynamics across this tropical/subtropical mountainous islandin the Pacific Ocean, which provides an opportunity to forecast the responses and feedbacks of terrestrial environments to future climate scenarios.
基金supported by the National Basic Research Program of China (Grant No. 2013CB430201)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA11010404)
文摘This study presents a dynamically downscaled climatology over East Asia using the non-hydrostatic Weather Research and Forecasting (WRF) model, forced by the Twentieth Century Reanalysis (20CR-v2). The whole experiment is a 111-year (1900--2010) continuous run at 50 km horizontal resolution. Comparisons of climatic means and seasonal cycles among observations, 20CR-v2, and WRF results during the last 30 years (1981-2010) in China are presented, with a focus on sur- face air temperature and precipitation in both summer and winter. The WRF results reproduce the main features of surface air temperature in the two seasons in China, and outperform 20CR-v2 in regional details due to topog- raphic forcing. Summer surface air temperature biases are reduced by as much as 1℃-2℃. For precipitation, the simulation results reproduce the decreasing pattern from Southeast to Northwest China in winter. For summer rainfall, the WRF simulation results reproduce the correct magnitude and position of heavy rainfall around the southeastern coastal area, and are better than 20CR-v2. One of the significant improvements is that an unrealistic center of summer precipitation in Southeast China present in 20CR-v2 is eliminated. However, the simulated results underestimate winter surface air temperature in northern China and winter rainfall in some regions in southeastern China. The mean seasonal cycles of surface air tempera- ture and precipitation are captured well over most of sub-regions by the WRF model.
文摘The trends and features of China's climatic change in the past and future are analysed by applying station observations and GCM simulation results. Nationally, the country has warmed by 0.3℃ in annual mean air temperatureand decreased by 5% in annual precipitation over 1951-1990. Regionally, temperature change has varied from acooling of 0.3℃ in Southwest China to a'warming of 1 .0℃ in Northeast China. With the exception of South China,all regions of China have shown a declination in precipitation. Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation. Under doubled CO2 concentration,climatic change in China will tend to be warmer and moister, with increases of 4.5℃ in annual mean air temperatureand 11% in annual precipitation on the national scale. Future climatic change will reduce the temporal and spatialdifferences of climatic factors.
基金Open Research Fund Project of Fujian Meteorological Bureau(2019KH04)。
文摘[Objectives]This study was conducted to scientifically plan orange osmanthus planting in Pucheng County to promote the development of agricultural economy.[Methods]Two factors,the total number of days with daily average temperature≥15℃from March to August and the total number of days with daily average temperature≥20℃in September were determined as the regionalization index factors using the weather data and geographic information data of Pucheng County,according to the 80%guarantee rate principle,the mean square error method and the actual growth law of orange osmanthus.Then,according to the weighted stack method,comprehensively considering the on-site inspection results and expert opinions,the suitability of orange osmanthus planting layout in Pucheng County was evaluated,and the GIS spatial interpolation technology was applied to complete the refined agroclimatic regionalization.[Results]The growth of Pucheng orange osmanthus has a great relationship with the thermal conditions,and it is clear that the suitable,sub-suitable and unsuitable areas for orange osmanthus planting in Pucheng County have certain applicability and maneuverability.[Conclusions]This study will play a scientific guiding role in the industrialization and development of orange osmanthus planting in Pucheng County.
基金supported by the National Basic Research Program of China (2009CB421407)the Special Public Welfare Research Fund for Meteorological Profession of China Meteorological Administration (GYHY201006022)
文摘The different spatial distributions of aerosol-induced direct radiative forcing and climatic effects in a weak (2003) and a strong (2006) East Asian summer monsoon (EASM) circulation were simulated using a high-resolution regional climate model (RegCM3).Results showed that the atmospheric circulations of summer monsoon have direct relations with transport of aerosols and their climatic effects.Both the top-of-the-atmosphere (TOA) and the surface-negative radiative forcing of aerosols were stronger in weak EASM circulations.The main difference in aerosol-induced negative forcing in two summers varied between 2 and 14 W m-2 from the Sichuan Basin to North China,where a maximum in aerosol-induced negative forcing was also noticed in the EASM-dominated areas.The spatial difference in the simulated aerosol optical depth (AOD) in two summers generally showed the similar pictures.Surface cooling effects induced by aerosols were spatially more uniform in weak EASM circulations and cooler by about 1-4.5℃.A preliminary analysis here indicated that a weaker low-level wind speed not conducive to the transport and diffusion of aerosols could make more contributions to the differences in the two circulations.
基金funded by the National Natural Science Foundation of China(No.31971460 and 32271646)the National Key Research and Development Program of China(2021YFD2200401)。
文摘Climate change significantly impacts forest ecosystems in arid and semi-arid regions.However,spatiotemporal patterns of climate-sensitive changes in individual tree growth under increased climate warming and precipitation in north-west China is unclear.The dendrochronological method was used to study climate response sensitivity of radial growth of Picea schrenkiana from 158 trees at six sites during 1990-2020.The results show that climate warming and increased precipitation significantly promoted the growth of trees.The response to temperature first increased,then decreased.However,the response to increased precipitation and the self-calibrating Palmer Drought Severity Index(scPDSI)increased significantly.In most areas of the Tianshan Mountains,the proportion of trees under increased precipitation and scPDSI positive response was relatively high.Over time,small-diameter trees were strongly affected by drought stress.It is predicted that under continuous warming and increased precipitation,trees in most areas of the Tianshan Mountains,especially those with small diameters,will be more affected by precipitation.
基金The National Natural Science Foundation of China under contract Nos 42077410 and 41872112。
文摘Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world.
基金supported by the National Natural Science Foundation of China(Grant No.41875113).
文摘The influences of human activity on regional climate over China have been widely reported and drawn great attention from both the scientific community and governments.This paper reviews the evidence of the anthropogenic influence on regional climate over China from the perspectives of surface air temperature(SAT),precipitation,droughts,and surface wind speed,based on studies published since 2018.The reviewed evidence indicates that human activities,including greenhouse gas and anthropogenic aerosol emissions,land use and cover change,urbanization,and anthropogenic heat release,have contributed to changes in the SAT trend and the likelihood of regional record-breaking extreme high/low temperature events over China.The anthropogenically forced SAT signal can be detected back to the 1870s in the southeastern Tibetan Plateau region.Although the anthropogenic signal of summer precipitation over China is detectable and anthropogenic forcing has contributed to an increased likelihood of regional record-breaking heavy/low precipitation events,the anthropogenic precipitation signal over China is relatively obscure.Moreover,human activities have also contributed to a decline in surface wind speed,weakening of monsoon precipitation,and an increase in the frequency of droughts and compound extreme climate/weather events over China in recent decades.This review can serve as a reference both for further understanding the causes of regional climate changes over China and for sound decision-making on regional climate mitigation and adaptation.Additionally,a few key or challenging scientific issues associated with the human influence on regional climate changes are discussed in the context of future research.
基金jointly supported by the National Natural Science Foundation of China under Grant No. 41975081the Research Funds for the Frontiers Science Center for Critical Earth Material Cycling Nanjing Universitythe Fundamental Research Funds for the Central Universities (Grant No. 020914380103)。
文摘Human activities have notably affected the Earth’s climate through greenhouse gases(GHG), aerosol, and land use/land cover change(LULCC). To investigate the impact of forest changes on regional climate under different shared socioeconomic pathways(SSPs), changes in surface air temperature and precipitation over China under low and medium/high radiative forcing scenarios from 2021 to 2099 are analyzed using multimodel climate simulations from the Coupled Model Intercomparison Project Phase 6(CMIP6). Results show that the climate responses to forest changes are more significant under the low radiative forcing scenario. Deforestation would increase the mean, interannual variability, and the trend of surface air temperature under the low radiative forcing scenario, but it would decrease those indices under the medium/high radiative forcing scenario. The changes in temperature show significant spatial heterogeneity. For precipitation, under the low radiative forcing scenario, deforestation would lead to a significant increase in northern China and a significant decrease in southern China, and the effects are persistent in the near term(2021–40), middle term(2041–70), and long term(2071–99). In contrast, under the medium/high radiative forcing scenario, precipitation increases in the near term and long term over most parts of China, but it decreases in the middle term, especially in southern, northern,and northeast China. The magnitude of precipitation response to deforestation remains comparatively small.
基金Supported by the Second Tibetan Plateau Scientific Expedition and Research Pro-gram(STEP)(2019QZKK0303-02)the Foundation of Science and Technology Development of Sichuan Province Key Laboratory of Heavy Rain and Drought-Flood Disasters in Plateau and Basin(SCQXKJYJXMS202109).
文摘Based on the meteorological data and DEM data in the producing areas of Morchella esculenta in the western Sichuan plateau from 1991 to 2020, the biological characteristics of M. esculenta, as well as the survey of production in the planting area, the correlation between M. esculenta production and the climatic ecological conditions at an altitude of 1 200-3 000 m in the western Sichuan plateau was comprehensively analyzed by using the inverse distance weight method, analytic hierarchy process, climate risk assessment model and geographic information system(GIS), and restrictive or high impact climatic ecological factors were selected as the suitability zoning indicators to carry out the analysis of climatic ecological suitability and planting zoning. The results show that the climatic factors affecting M. esculenta cultivation in the western Sichuan plateau were mainly temperature, temperature difference between day and night, and humidity, and the main meteorological disaster was freezing disaster. Under the influence of vertical changes in temperature, topography and cold damage, the growing areas of M. esculenta in the western Sichuan plateau were mainly distributed in the Minjiang River basin and the river valley along the Dadu River basin at an altitude of 1 200-2 000 m, and were distributed in strips and branches along the rivers. The suitable areas were mainly distributed in Wenchuan, Lixian, Maoxian, Kangding, Jiulong and Luding counties(cities), which were the main producing areas of M. esculenta, but the area was small, accounting for only 3.5% of the study area;the sub-suitable areas were mainly distributed in some towns of Danba, Xiaojin, Wenchuan, Lixian, Maoxian, Heishui and Jiuzhaigou counties, accounting for 36.0% of the total area, and they were the main planting areas of M. esculenta.
基金This work was jointly supported by the National Key Research and Development Program of China(2022YFC3201703)the National Natural Science Foundation of China(41805074)+1 种基金China Three Gorges Corporation(0704181)the key Innovation Team of China Meteorological Administration Climate Change Detection and Response(CMA2022ZD03).
文摘Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation planning.Previous related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate models.Here,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation effects.Two experiments were conducted with and without winter wheat irrigation to isolate the effects of irrigation.Results showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil moisture.Moreover,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation schemes.Winter wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum temperature.Additionally,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the atmosphere.Further analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and agriculture.Fortunately,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated region.Additionally,no notable change was found in terms of heavy rainfall events and precipitation intensity,which might be an undereastimation caused by the less water use in model simulation.Although winter wheat irrigation does not have notable impact on the climate of the surrounding region,it is an important factor for the local-scale climate.
基金Supported by Special Fund of Sichuan Financial Genetic Engineering(2011QNJJ-019)Science and Technology Support Program of Sichuan Province(2011NZ0068)"12th Five-Year Plan" Breeding Project of Crops and Livestock of Sichuan Province(2011NZ0098-15)~~
文摘[Objective] The aim was to make full use of light-heat resources to expand the potato planting area on the base of ensuring the production of main grain crops and the limited arable land. [Methods] Through catch crops, multiple cropping and intercropping, new multiple planting patterns of potato with efficiency are constructed, for the purpose of increasing yield and benefit of potato. [Result] In irrigated plain and hill area, three new planting patterns such as autumn potato/rope-rice,winter potato-rice-autumn potato, and autumn(winter) potato-rice were constructed.In dry land of plain and hill area, three new planting patterns such as spring(winter)potato/maize/sweet potato, spring(winter) potato/maize-autumn potato, and wheat + winter potato/maize/sweet potato were constructed. In plateau mountainous area, spring potato/maize was constructed. [Conclusion] With use of new planting patterns, the cropping index of new patterns was 200%-300%, while the accumulated temperature utilization was 68.9%-93.4%, light energy utilization was 0.98%-1.59% and straw utilization was 50%-100%. To compared with traditional planting patterns, the yield increased by 2.6%-93%, and benefit increased by 15.8%-284.3%. Furthermore,multiple planting patterns of potato have become main planting patterns in increasing yield and income in Sichuan.
基金supported by the National Basic Research Program of China (2009CB421407,2006CB403707,and2007BAC03A01)the R & D Special Fund for Public Welfare Industry(meteorol-ogy)(GYHY200806010)Chinese Academy of Sciences(Grant NOKZCX2-YW-Q1-02)
文摘This paper describes the construction of a 0.5°× 0.5° daily temperature dataset for the period of 1961- 2005 over China's Mainland for the purpose of climate model validation. The dataset is based on the interpolation from 751 observing stations in China and comprises 3 variables: daily mean, minimum, and maximum temperature. The "anomaly approach" is applied in the interpolation. The gridded climatology of 1971-2000 is first calculated and then a gridded daily anomaly for 1961-2005 is added to the climatology to obtain the final dataset. Comparison of the dataset with CRU (Climatic Research Unit) observations at the monthly scale shows general agreement between the two datasets. The differences found can be largely attributed to the introduction of observations at new stations. The dataset shows similar interannual variability as does CRU data over North China and eastern part of the Tibetan Plateau, but with a slightly larger linear trend. The dataset is employed to validate the simulation of three extreme indices based on daily mean, minimum, and maximum temperature by a high-resolution regional climate model. Results show that the model reproduces these indices well. The data are available at the National Climate Center of China Meteorological Administration, and a coarser resolution (1°× 1°) version can be accessed via the World Wide Web.
基金Thanks are due to CSIRO in Australia and the Institute of Botany,Chinese Academy of Sciences,National Climate Center of China , for providing the data sets of the GCM and the vegetation coverThis research was supported by the National Natural Science Foundation of China under Grant No, 40125014National Key Programme for Developing Basic Sciences (G1998040900-part 1).
文摘Changes of extreme events due to greenhouse effects (2 × CO<SUB>2</SUB>) over East Asia, with a focus on the China region as simulated by a regional climate model (RegCM2), are investigated. The model is nested to a global coupled ocean-atmosphere model (CSIRO R21L9 AOGCM). Analysis of the control run of the regional model indicates that it can reproduce well the extreme events in China. Statistically significant changes of the events are analyzed. Results show that both daily maximum and daily minimum temperature increase in 2 × CO<SUB>2</SUB> conditions, while the diurnal temperature range decreases. The number of hot spell days increases while the number of cold spell days decreases. The number of rainy days and heavy rain days increases over some sub-regions of China. The 2 × CO<SUB>2</SUB> conditions also cause some changes in the tropical storms affecting China.
文摘Climate effects of land use change in China as simulated by a regional climate model (RegCM2) are investigated. The model is nested in one-way mode within a global coupled atmosphere-ocean model (CSIRO R21L9 AOGCM). Two multi-year simulations, one with current land use and the other with potential vegetation cover, are conducted. Statistically significant changes of precipitation, surface air temperature, and daily maximum and daily minimum temperature are analyzed based on the difference between the two simulations. The simulated effects of land use change over China include a decrease of mean annual precipitation over Northwest China, a region with a prevalence of arid and semi-arid areas; an increase of mean annual surface air temperature over some areas; and a decrease of temperature along coastal areas. Summer mean daily maximum temperature increases in many locations, while winter mean daily minimum temperature decreases in East China and increases in Northwest China. The upper soil moisture decreases significantly across China. The results indicate that the same land use change may cause different climate effects in different regions depending on the surrounding environment and climate characteristics.
基金supported by the National Basic Research Program of China (Grant No. 2010CB 950903)the China-UK-Swiss Adapting to Climate Change in China Project (ACCC)-Climate Science
文摘Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission scenarios of the Representative Concentration Pathways—RCP4.5 and RCP8.5.This is based on a period of transient simulations from 1950 to2099,with a grid spacing of 50 km.The present paper focuses on the annual mean temperature and precipitation in China over this period,with emphasis on their future changes.Validation of model performance reveals marked improvement of the RegCM4.0 model in reproducing present day temperature and precipitation relative to the driving BCC_CSM1.1 model.Significant warming is simulated by both BCC_CSM1.1 and RegCM4.0,however,spatial distribution and magnitude differ between the simulations.The high emission scenario RCP8.5 results in greater warming compared to RCP4.5.The two models project different precipitation changes,characterized by a general increase in the BCC_CSM1.1,and broader areas with decrease in the RegCM4.0 simulations.