Atmospheric Intercomparison Project simulations of the summertime diurnal cycle of precipitation and low-level winds over subtropical China by Intergovernmental Panel on Climate Change Fifth Assessment Report models w...Atmospheric Intercomparison Project simulations of the summertime diurnal cycle of precipitation and low-level winds over subtropical China by Intergovernmental Panel on Climate Change Fifth Assessment Report models were evaluated. By analyzing the diurnal variation of convective and stratiform components, results confirmed that major biases in rainfall diurnal cycles over subtropical China are due to convection parameterization and further pointed to the diurnal variation of convective rainfall being closely related to the closure of the convective scheme. All models captured the early-morning peak of total rainfall over the East China Sea, but most models had problems in simulating diurnal rainfall variations over land areas of subtropical China. When total rainfall was divided into stratiform and convective rainfall, all models successfully simulated the diurnal variation of stratiform rainfall with a maximum in the early morning. The models, overestimating noon-time （nocturnal） total rainfall over land, generally simulated too much convective rainfall, which peaked close to noon （midnight）, sharing some similarities in the closures of their deep convection schemes. The better performance of the Meteorological Research Institute atmospherer. ocean coupled global climate model version 3 （MRI-CGCM3） is attributed to the well captured ratio of the two kinds of rainfall, but not diurnal variations of the two components. Therefore, a proper ratio of convective and stratiform rainfall to total rainfall is also important to improve simulated diurnal rainfall variation.展开更多
This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 （the Intergovernmental Panel on Climate Change Fifth Assessment Report） em...This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 （the Intergovernmental Panel on Climate Change Fifth Assessment Report） emissions inventories and a fully coupled chemistry-aerosol general circulation model. As compared to the previous Global Emissions Inventory Activity （GEIA） data, that have been commonly used for forcing estimates since 1990, the IPCC AR5 emissions inventories report lower anthropogenic emissions of organic carbon and black carbon aerosols and higher sulfur and NOx emissions. The simulated global and annual mean burdens of sulfate, nitrate, black carbon （BC）, primary organic aerosol （POA）, secondary organic aerosol （SOA）, and ozone were 0.79, 0.35, 0.05, 0.49, 0.34, and 269 Tg, respectively, in the year 1850, and 1.90, 0.90, 0.11, 0.71, 0.32, and 377 Tg, respectively, in the year 2000. The estimated annual mean top of the atmosphere （TOA） direct radiative forcing of all anthropogenic aerosols based on the AR5 emissions inventories is -0.60 W m^-2 on a global mean basis from 1850 to 2000. However, this is -2.40 W m-2 when forcing values are averaged over eastern China （18-45°N and 95-125°E）. The value for tropospheric ozone is 0.17 W m^-1 on a global mean basis and 0.24 W m^-2 over eastern China. Forcing values indicate that the climatic effect of aerosols over eastern China is much more significant than the globally averaged effect.展开更多
This article contributes to research on how climate change will impact crops in China by moving from ex-post empirical analysis to forecasting. We construct a multiple regression model, using agricultural observations...This article contributes to research on how climate change will impact crops in China by moving from ex-post empirical analysis to forecasting. We construct a multiple regression model, using agricultural observations and meteorological simulations by GCMs, to simulate the possible planting boundaries and suitable planting re- gions of spring wheat under RCP4.5 scenario for the base period 2040s and 2070s. We find that the south bound- ary of possible planting region for spring wheat spreads along the belt： south Shandong-north Jiangsu-north Anhui-central Henan-north Hubei-southeast Sichuan-north Yunnan provinces, and will likely move northward under RCP4.5 scenario in 2040s and 2070s, resulting in the decrease of possible planting area in China. Moreover, the sowing and harvest date of spring wheat in the base period shows a gradually delayed phenomenon from the belt： south Xinjiang - Gansu, to the Tibet Plateau. As a result, the growth period of spring wheat in China will shorten because of the impacts of climate change. These results imply that a variety of adaptations measures should be set up in response to changing climatic conditions, including developing the planting base for spring wheat, restricting the planting area of spring wheat in sub-suitable areas at risk while expanding the planting area of optimal crops.展开更多
A decadal climate prediction was performed by a coupled global climate model FGOALS_gl developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) within t...A decadal climate prediction was performed by a coupled global climate model FGOALS_gl developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) within the Institute of Atmospheric Physics(IAP),Chinese Academy of Sciences.First,an Incremental Analysis Updates(IAU) scheme was applied to assimilate surface and subsurface ocean temperature and salinity fields derived from oceanic objective analysis data,for the initialization of the ocean component of the model.Starting from the initialized states,hindcast integrations were performed with the specified historical solar cycle variations,concentrations of greenhouse gasses and sulfate aerosol,following the standard 20C3M scenario used in phase three of the Coupled Model Intercomparison Project(CMIP3).Based on the hindcast integrations,we performed forecast integrations under the radiative forcing of the A1B scenario in the CMIP3.Compared with the 20C3M run,the hindcast integrations have a much higher ability to simulate the decadal variability of SST(Sea Surface Temperature) in the tropical central-eastern Pacific and mid-latitude northeastern Pacific.This suggests that the ocean initialization is able to enhance the model skill in the regions with large decadal variability.The forecast integrations suggest that the SST in the tropical central-eastern Pacific has reached its trough phase,and will gradually increase in the following 10-15 years.Meanwhile,the global mean surface temperature predicted by the forecast integrations increases slower than that projected by the A1B scenario run over 2000-2010,but faster than the latter after that.展开更多
基金jointly supported by the Major National Basic Research Program of China(973 Program)on Global Change(Grant No.2010CB951902)the National Natural Science Foundation of China(Grant Nos.41221064 and 41205053)the China R&D Special Fund for Public Welfare Industry(meteorology)(Grant No.GYHY201306068)
文摘Atmospheric Intercomparison Project simulations of the summertime diurnal cycle of precipitation and low-level winds over subtropical China by Intergovernmental Panel on Climate Change Fifth Assessment Report models were evaluated. By analyzing the diurnal variation of convective and stratiform components, results confirmed that major biases in rainfall diurnal cycles over subtropical China are due to convection parameterization and further pointed to the diurnal variation of convective rainfall being closely related to the closure of the convective scheme. All models captured the early-morning peak of total rainfall over the East China Sea, but most models had problems in simulating diurnal rainfall variations over land areas of subtropical China. When total rainfall was divided into stratiform and convective rainfall, all models successfully simulated the diurnal variation of stratiform rainfall with a maximum in the early morning. The models, overestimating noon-time （nocturnal） total rainfall over land, generally simulated too much convective rainfall, which peaked close to noon （midnight）, sharing some similarities in the closures of their deep convection schemes. The better performance of the Meteorological Research Institute atmospherer. ocean coupled global climate model version 3 （MRI-CGCM3） is attributed to the well captured ratio of the two kinds of rainfall, but not diurnal variations of the two components. Therefore, a proper ratio of convective and stratiform rainfall to total rainfall is also important to improve simulated diurnal rainfall variation.
基金supported by the National Natural Science Foundation of China (Grant Nos.90711004 and40825016)the Chinese Academy of Sciences (Grant Nos.KZCX2-YW-Q1 and KZCX2-YW-Q11-03)
文摘This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 （the Intergovernmental Panel on Climate Change Fifth Assessment Report） emissions inventories and a fully coupled chemistry-aerosol general circulation model. As compared to the previous Global Emissions Inventory Activity （GEIA） data, that have been commonly used for forcing estimates since 1990, the IPCC AR5 emissions inventories report lower anthropogenic emissions of organic carbon and black carbon aerosols and higher sulfur and NOx emissions. The simulated global and annual mean burdens of sulfate, nitrate, black carbon （BC）, primary organic aerosol （POA）, secondary organic aerosol （SOA）, and ozone were 0.79, 0.35, 0.05, 0.49, 0.34, and 269 Tg, respectively, in the year 1850, and 1.90, 0.90, 0.11, 0.71, 0.32, and 377 Tg, respectively, in the year 2000. The estimated annual mean top of the atmosphere （TOA） direct radiative forcing of all anthropogenic aerosols based on the AR5 emissions inventories is -0.60 W m^-2 on a global mean basis from 1850 to 2000. However, this is -2.40 W m-2 when forcing values are averaged over eastern China （18-45°N and 95-125°E）. The value for tropospheric ozone is 0.17 W m^-1 on a global mean basis and 0.24 W m^-2 over eastern China. Forcing values indicate that the climatic effect of aerosols over eastern China is much more significant than the globally averaged effect.
基金National Natural Sciences Foundation of China(Study on allocation of water and land resources based on food security at population peaks in ChinaNo.41471463)
文摘This article contributes to research on how climate change will impact crops in China by moving from ex-post empirical analysis to forecasting. We construct a multiple regression model, using agricultural observations and meteorological simulations by GCMs, to simulate the possible planting boundaries and suitable planting re- gions of spring wheat under RCP4.5 scenario for the base period 2040s and 2070s. We find that the south bound- ary of possible planting region for spring wheat spreads along the belt： south Shandong-north Jiangsu-north Anhui-central Henan-north Hubei-southeast Sichuan-north Yunnan provinces, and will likely move northward under RCP4.5 scenario in 2040s and 2070s, resulting in the decrease of possible planting area in China. Moreover, the sowing and harvest date of spring wheat in the base period shows a gradually delayed phenomenon from the belt： south Xinjiang - Gansu, to the Tibet Plateau. As a result, the growth period of spring wheat in China will shorten because of the impacts of climate change. These results imply that a variety of adaptations measures should be set up in response to changing climatic conditions, including developing the planting base for spring wheat, restricting the planting area of spring wheat in sub-suitable areas at risk while expanding the planting area of optimal crops.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDA05110305)the National Basic Research Program of China (2010CB951904)+2 种基金the National Natural Science Foundation of China (41005040)the Program of Excellent State Key Laboratory (41023002)the National High-Tech Research and Development Plan of China (2010AA012302)
文摘A decadal climate prediction was performed by a coupled global climate model FGOALS_gl developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) within the Institute of Atmospheric Physics(IAP),Chinese Academy of Sciences.First,an Incremental Analysis Updates(IAU) scheme was applied to assimilate surface and subsurface ocean temperature and salinity fields derived from oceanic objective analysis data,for the initialization of the ocean component of the model.Starting from the initialized states,hindcast integrations were performed with the specified historical solar cycle variations,concentrations of greenhouse gasses and sulfate aerosol,following the standard 20C3M scenario used in phase three of the Coupled Model Intercomparison Project(CMIP3).Based on the hindcast integrations,we performed forecast integrations under the radiative forcing of the A1B scenario in the CMIP3.Compared with the 20C3M run,the hindcast integrations have a much higher ability to simulate the decadal variability of SST(Sea Surface Temperature) in the tropical central-eastern Pacific and mid-latitude northeastern Pacific.This suggests that the ocean initialization is able to enhance the model skill in the regions with large decadal variability.The forecast integrations suggest that the SST in the tropical central-eastern Pacific has reached its trough phase,and will gradually increase in the following 10-15 years.Meanwhile,the global mean surface temperature predicted by the forecast integrations increases slower than that projected by the A1B scenario run over 2000-2010,but faster than the latter after that.
