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Impact of Different East Asian Summer Monsoon Circulations on Aerosol-Induced Climatic Effects

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Atmospheric and Oceanic Science Letters 2013年第5期6卷 227-232页

作者： JU Li-Xia han zhi-wei Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Key Laboratory of Regional Climate-Environment for East Asia Institute of Atmospheric Physics Chinese Academy of Sciences

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 *** the top-of-the-atmosphere （TOA） and the surface-negative radiative forcing of aerosols were stronger in weak EASM *** 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 *** spatial difference in the simulated aerosol optical depth （AOD） in two summers generally showed the similar *** 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.

关键词： aerosols climatic effects East Asian summer monsoon regional climate model

Modeling Study of the Impact of Heterogeneous Reactions on Dust Surfaces on Aerosol Optical Depth and Direct Radiative Forcing over East Asia in Springtime

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Atmospheric and Oceanic Science Letters 2011年第6期4卷 309-315页

作者： LI Jia-wei han zhi-wei Key Laboratory of Regional Climate-Environment Research for Temperate East Asia （RCE-TEA） Institute of Atmospheric PhysicsChinese Academy of Sciences Beijing 100029 China

The spatial distributions and interannual variations of aerosol concentrations, aerosol optical depth （AOD）, aerosol direct radiative forcings, and their responses to heterogeneous reactions on dust surfaces over East Asia in March 2006-10 were investigated by utilizing a regional coupled climate-chemistry/aerosol model. Anthropogenic aerosol concentrations （inorganic ＋ carbonaceous） were higher in March 2006 and 2008, whereas soil dust reached its highest levels in March 2006 and 2010, resulting in stronger aerosol radiative forcings in these periods. The domain and five-year （2006-10） monthly mean concentrations of anthropogenic and dust aerosols, AOD, and radiative forcings at the surface （SURF） and at the top of the atmosphere （TOA） in March were 2.4 μg m 3 13.1 lag m^-3, 0.18, -19.0 W m^-2, and -7.4 W m^-2, respectively. Heterogeneous reactions led to an increase of total inorganic aerosol concentration; however, the ambient inorganic aerosol concentration decreased, resulting in a smaller AOD and weaker aerosol radiative forcings. In March 2006 and 2010, the changes in ambient inorganic aerosols, AOD, and aerosol radiative forcings were more evident. In terms of the domain and five-year averages, the total inorganic aerosol concentrations increased by 13.7% （0.17 μg m^-3） due to heterogeneous reactions, but the ambient inorganic aerosol concentrations were reduced by 10.5% （0.13 lag m-3）. As a result, the changes in AOD, SURF and TOA radiative forcings were estimated to be -3.9% （-0.007）, -1.7% （0.34 W m^-2）, and -4.3% （0.34 W m^-2）, respectively, in March over East Asia.

关键词： heterogeneous reaction aerosol concentra- tion aerosol optical depth radiative forcing East Asia

Regional Oceanic Impact on Circulation and Direct Radiative Effect of Aerosol over East Asia

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Atmospheric and Oceanic Science Letters 2011年第6期4卷 324-329页

作者： XIONG Zhe han zhi-wei Key Laboratory of Regional Climate-Environment for East Asia Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029 China

The Regional Integrated Environmental Model System （RIEMS 2.0） coupled with a chemistry-aerosol model and the Princeton Ocean Model （POM） is employed to simulate regional oceanic impact on atmospheric circulation and the direct radiative effect （DRE） of aerosol over East Asia. The aerosols considered in this study include both major anthropogenic aerosols （e.g., sulfate, black carbon, and organic carbon） and natural aerosols （e.g., soil dust and sea salt）. The RIEMS 2.0 is driven by NCEP/NCAR reanalysis II, and the simulated period is from 1 January to 31 December 2006. The results show the following：（1） The simulated annual mean sea-level pressure by RIEMS 2.0 with POM is lower than without POM over the mainland and higher without POM over the ocean. （2） In summer, the subtropical high simulated by RIEMS 2.0 with POM is stronger and extends further westward, and the continental low is stronger than without POM in summer. （3） The aerosol optical depth （AOD） simulated by RIEMS 2.0 with POM is larger in the middle and lower reaches of the Yangtze River than without POM. （4） The direct radiative effect with POM is stronger than that without POM in the middle and lower reaches of the Yangtze River and parts of southern China. Therefore, the authors should take account of the impact of the regional ocean model on studying the direct climate effect ＆aerosols in long term simulation.

关键词： aerosols direct radiative effect circulation regional ocean model the Regional Integrated Environ- mental Model System 2.0

Modeling of the Second Indirect Effect of Anthropogenic Aerosols in East Asia

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Atmospheric and Oceanic Science Letters 2011年第6期4卷 316-323页

作者： WU Peng-Ping han zhi-wei Key Laboratory of Regional Climate-Environment Researeh for Temperate East Asia （RCE-TEA） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Institute of Plateau Meteorlogy China Meteorological Administration Chengdu 610072 China

This study investigated the second indirect climatic effect of anthropogenic aerosols,including sulfate,organic carbon(OC) ,and black carbon(BC) ,over East *** seasonal variation of the climatic response to the second indirect effect was also *** simulation period for this study was *** to a decrease in autoconversion rate from cloud water to rain as a result of aerosols,the cloud liquid water path(LWP) ,and radiative flux(RF) at the top of the atmosphere(TOA) changed dramatically,increasing by 14.3 g m-2 and decreasing by-4.1 W m-2 in terms of domain and annual *** LWP and RF changed most in autumn. There were strong decreases in ground temperature in Southwest China,the middle reaches of the Yangtze River in spring and autumn,while maximum cooling of up to-1.5 K occurred in the Chongqing *** regional and annual mean change in ground temperature reached-0.2 K over eastern *** all seasons except summer,precipitation generally decreased in most areas north of the Yangtze River,whereas precipitation changed little in South *** changed most in summer,with alternating bands of increasing(～40 mm) and decreasing(～40 mm) precipitation appearing in eastern *** decreased by 1.5-40 mm over large areas of Northeast China and the Huabei *** domain and annual mean change in precipitation was approximately-0.3 mm over eastern *** maximum reduction in precipitation occurred in summer,with mean absolute and relative changes of-1.2 mm and-3.8%over eastern *** study revealed considerable climate responses to the second indirect effect of aerosols over specific regions of China.

关键词： aerosols second indirect effect autoconversion liquid water path model simulation

Direct Radiative Forcing and Climatic Effects of Aerosols over East Asia by RegCM3

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Atmospheric and Oceanic Science Letters 2011年第6期4卷 363-367页

作者： JU Li-Xia han zhi-wei Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Nansen -Zhu International Researeh Centre institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Key Laboratory of Regional Climate-Environment for East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

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.

关键词： regional climate model aerosols direct radiative forcing climatic effects

Indirect Radiative and Climatic Effects of Sulfate and Organic Carbon Aerosols over East Asia Investigated by RIEMS

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Atmospheric and Oceanic Science Letters 2011年第1期4卷 7-11页

作者： WU Peng-Ping han zhi-wei Key Laboratory of Regional Climate-Environment Research for Temperate East Asia （RCE-TEA） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

The indirect radiative and climatic effects of sulfate and organic carbon aerosols over East Asia were investigated using a Regional Integrated Environment Model System (RIEMS) with an empirical aerosol-cloud *** first indirect radiative forcing was negative and ranged from-9-0 W m-2 in the *** maximum cooling,up to-9 W m-2,occurred in the Chongqing District in winter,whereas the cooling areas were larger during summer than in *** carbon (OC) aerosols were more abundant in winter than in summer,whereas the sulfate concentration during summer was much higher than during *** concentrations of sulfate and OC were comparable in winter,and sulfate played a dominant role in determining indirect radiative forcing in summer,whereas in winter,both sulfate and OC were *** regional mean indirect radiative forcings were-0.73 W m-2 and-0.41 W m-2 in summer and winter,*** surface cooling caused by indirect effects was more obvious in winter than that in *** ground temperature decreased by ～1.2 K in most areas of eastern China in winter,whereas in summer,the temperature decreased (～-1.5 K) in some regions,such as the Yangtze River region,but increased (～0.9 K) in the areas between the Yellow and Yangtze *** winter,the precipitation decreased by 0-6 mm in most areas of eastern China,but in summer,alternating bands of increasing (up to 80 mm) and decreasing (～-80 mm) precipitation appeared in eastern China.

关键词： indirect radiative forcing climatic effect sulfate organic carbon RIEMS

Direct Climatic Effect of Aerosols and Interdecadal Variations over East Asia Investigated by a Regional Coupled Climate-Chemistry/Aerosol Model

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Atmospheric and Oceanic Science Letters 2011年第6期4卷 299-303页

作者： han zhi-wei XIONG Zhe LI Jia-wei Key Laboratory of Regional Climate-Environment Research for Temperate East Asia （RCE-TEA） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols （sulfate, black carbon, and organic carbon） and natural aerosols （soil dust and sea salt）. Anthropogenic emissions used in model simulation are from a global emission inventory prepared for the Intergovernmental Panel on Climate Change Fifth Assessment Report （IPCC AR5）, whereas natural aerosols are calculated online in the model. The simulated 20-year average direct solar radiative effect due to aerosols at the surface was estimated to be in a range of-9- -33 W m-2 over most areas of China, with maxima over the Gobi desert of West China, and-12 W m-2 to -24 W m-2 over the Sichuan Basin, the middle and lower reaches of the Yellow River and the Yangtze River. Aerosols caused surface cooling in most areas of East Asia, with maxima of-0.8℃ to -1.6℃ over the deserts of West China, the Sichuan Basin, portions of central China, and the middle reaches of the Yangtze River. Aerosols induced a precipitation decrease over almost the entire East China, with maxima of-90 mm/year to -150 mm/year over the Sichuan Basin, the middle reaches of the Yangtze River and the lower reaches of the Yellow River. Interdecadal variation of the climate response to the aerosol direct radiative effect is evident, indicating larger decrease in surface air temperature and stronger per- turbation to precipitation in the 1990s than that in the 1980s, which could be due to the interdecadal variation of anthropogenic emissions.

关键词： aerosols direct radiative effect climatic response interdecadal variation model simulation

Real-Time Slab Quality Diagnosis and Analysis System Based on Solidification Mechanism

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Journal of Iron and Steel Research International 2013年第12期20卷 40-46页

作者： FENG Ke WANG Shui-gen han zhi-wei KONG Yi-wen CAO Jian-feng CISDI Research and Development Co. Ltd. Continuous Casting Department CISDI Engineering Co.Ltd.

According to the two types of slab defects （surface crack and internal crack）, a real-time slab quality diag nosis and analysis system named CISDI_SQDS ONLINE R2011 was developed based on heat transfer and solidifica tion simulation, stress and strain calculation as well as metallurgical process analysis about continuous casting, com- bined with expert knowledge database for specific casting events. The respective crack formation indexes were intro duced as the theoretical reference data for slab quality level evaluation. Meanwhile, both the quality loss factors relat ed to casting metallurgical rules and the adjusting factors related to casting events were taken into full consideration, which was integrated organically with theoretical analysis and expert system. The system can be widely used as an important theoretical tool for prediction and control of slab quality in slab continuous casting process.

关键词： slab continuous casting internal crack surface crack quality diagnosis

Application and Numerical Simulation of Electromagnetic Stirring in Secondary Cooling Zone During Continuous Casting of Ultra-Thick Slab

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Journal of Iron and Steel Research International 2012年第S2期19卷 977-982页

作者： QU Tian-peng REN Bing-zhi han zhi-wei FENG Ke CISDI Chongqing Iron & Steel making Plant Integration Co. Ltd.

The segregation of solute elements at solidification front could be greatly improved by application of electromagnetic stirring(SEM)in secondary cooling *** location of SEM in secondary cooling zone affects the operational *** the present study,based on the application of SEM in Ultra-thick slab continuous casting,the shell thickness was calculated by self-programming code and the results were verified by nail-shooting test.A numerical model was established to calculate the fluid flow of molten steel under shell to determine the suitable SEM location in secondary cooling *** results shows that the velocity of molten steel increases with increase of stirring current which enhance the circulatory flow of unset steel at solidification ***,in order to fully develop ability of SEM it is necessary to select suitable stirring current and mode for ultra-thick slab *** calculation provides theoretical base for application of SEM in secondary cooling zone during ultra-thick slab casting process.

关键词： Electromagnetic stirring Secondary cooling zone Ultra-thick slab Continuous casting