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radiative forcing and Climate Response Due to Black Carbon in Snow and Ice

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Advances in Atmospheric Sciences 2011年第6期28卷 1336-1344页

作者：王志立张华沈学顺 Center for Atmosphere Watch and Services Chinese Academy of Meteorological Sciences China Meteorological Administration Graduate University of Chinese Academy of Sciences National Climate Center China Meteorological Administration State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGCM2.0.1） developed by the National Climate Center（NCC） of the China Meteorological Administration（CMA）.The results show that the global annual mean surface radiative forcing due to BC in snow/ice is ＋0.042 W m 2,with maximum forcing found over the Tibetan Plateau and regional mean forcing exceeding ＋2.8 W m *** global annual mean surface temperature increased 0.071 C due to BC in snow/*** surface radiative forcing was clearly shown in winter and spring and increased the surface temperature of snow/ice in the Northern *** surface temperatures of snow-covered areas of Eurasia and North America in winter（spring） increased by 0.83 C（0.6 C） and 0.83 C（0.46 C）,*** rates also increased greatly,leading to earlier snowmelt and peak runoff *** the rise of surface temperatures in the Arctic,more water vapor could be released into the atmosphere,allowing easier cloud formation,which could lead to higher thermal emittance in the ***,the total cloud forcing could decrease due to increasing cloud cover,which will offset some of the positive feedback mechanism of the clouds.

关键词： black carbon snow/ice radiative forcing climate effects

radiative forcing and global warming potential of perfluorocarbons and sulfur hexafluoride

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Science China Earth Sciences 2011年第5期54卷 764-772页

作者： ZHANG Hua WU JinXiu SHEN ZhongPing Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing 100081 China Shanghai Meteorological Media Center Shanghai 200030 China Shanghai Climate Center Shanghai 200030 China

We developed two radiation parameterizations with different resolutions （17-band and 998-band） for perfluorocarbons （PFCs） and sulfur hexafluoride （SF6） using the updated High-resolution Transmission Molecular Absorption （HITRAN） 2004 database and the correlated k-distribution method. We analyzed the impacts of the two radiation schemes on heating rates. Then we studied their instantaneous radiative efficiency, stratospheric adjusted radiative efficiency, global warming potential （GWP）, and global temperature potential （GTP）, for both clear- and all-sky conditions using a high-resolution radiation scheme. We found that the stratosphere-adjusted radiative efficiencies of C2F6, CF4, and SF6 for the whole sky were 0.346, 0.098, and 0.680 W m^-2 ppbv^-1, respectively. radiative forcing from the industrial revolution to 2005 was 0.001, 0.007, and 0.004 W m^-2, respectively; and was predicted to rise to 0.008, 0.036, and 0.037 W m^-2, respectively, by 2100, according to emission scenarios provided by the IPCC. The GWPs of C2F6, CF4, and SF6 are 17035, 7597, and 31298, respectively, for a time horizon of 100 years relative to CO2. Their GTPs of pulse and sustained emissions, GTPv and GTPs, are 22468, 10052, and 40935 and 16498, 7355, and 30341, respectively, for a 100-year time horizon.

关键词： PFCs SF6 radiative forcing global warming potential (GWP) global temperature potential (GTP) correlatedk-distribution

Ground-based measurements of aerosol optical properties and radiative forcing in North China

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China Particuology 2007年第3期5卷 202-205页

作者： Hongbin Chen Xiangao Xia Pucai Wang Wenxing Zhang Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

In order to gain an insight into the aerosol properties and their climatic effect over the continental source regions of China, it is of significance to carry out long-term ground-based measurements of aerosol optical properties and radiative forcing. A couple of temporary and permanent Aerosol Robotic Network （AERONET） sites and three comprehensive radiative sites were established in China as a result of international cooperation in recent years. Heavy aerosol loading and significant temporal and spatial variation over North China are revealed by the AERONET data. Aerosol-induced reductions in surface radiation budget are examined on the basis of collocated observations by sun photometers and pyranometers. 2007 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.

关键词： Aerosol Optical properties radiative forcing

An Updated Estimation of radiative forcing due to CO_2 and Its Effect on Global Surface Temperature Change

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Advances in Atmospheric Sciences 2013年第4期30卷 1017-1024页

作者：张华张若玉石广玉 Laboratory for Climate Studies China Meteorological Administration National Climate Center Atmosphere Science Academy Nanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics

New estimations of radiative forcing due to CO2 were calculated using updated concentration data of CO2 and a high-resolution radiative transfer model. The stratospheric adjusted radiative forcing （ARF） due to CO2 from the year 1750 to the updated year of 2010 was found to have increased to 1.95 W m-2, which was 17% larger than that of the IPCC＇s 4th Assessment Report because of the rapid increase in CO2 concentrations since 2005. A new formula is proposed to accurately describe the relationship between the ARF of CO2 and its concentration. Furthermore, according to the relationship between the ARF and surface temperature change, possible changes in equilibrium surface temperature were estimated under the scenarios that the concentration of CO2 increases to 1.5, 2, 2.5, 3, 3.5 and 4 times that of the concentration in the year 2008. The result was values of ＋2.2℃, ＋3.8℃, ＋5.1℃, ＋6.2℃, ＋7.1℃ and ＋8.0℃ respectively, based on a middle-level climate sensitivity parameter of 0.8 K （W m 3）-1. Non-equilibrium surface temperature changes over the next 500 years were also calculated under two kinds of emission scenarios （pulsed and sustained emissions） as a comparison, according to the Absolute Global Temperature change Potential （AGTP） of CO2. Results showed that CO2 will likely continue to contribute to global warming if no emission controls are imposed, and the effect on the Earth-atmosphere system will be difficult to restore to its original level.

关键词： CO2 radiative forcing surface temperature change Global Temperature change Potential

Direct radiative forcing of urban aerosols over Pretoria(25.75°S, 28.28°E) using AERONET Sunphotometer data:First scientific results and environmental impact

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Journal of Environmental Sciences 2014年第12期26卷 2459-2474页

作者： Ayodele Joseph Adesina Kanike Raghavendra Kumar Venkataraman Sivakumar Derek Griffith Discipline of Physics School of Chemistry and Physics College of Agriculture Engineering and Science Westville CampusUniversity of Kwa Zulu–Natal Durban 4000 South Africa Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration School of Atmospheric PhysicsNanjing University of Information Science and Technology Optronic Sensor Systems Council for Scientific and Industrial Research (CSIR)–DPSS Pretoria 0001 South Africa

The present study uses the data collected from Cimel Sunphotometer of Aerosol Robotic Network（AERONET） for the period from January to December, 2012 over an urban site,Pretoria（PTR; 25.75°S, 28.28°E, 1449 m above sea level）, South Africa. We found that monthly mean aerosol optical depth（AOD, τa） exhibits two maxima that occurred in summer（February） and winter（August） having values of 0.36 ± 0.19 and 0.25 ± 0.14,respectively, high-to-moderate values in spring and thereafter, decreases from autumn with a minima in early winter（June） 0.12 ± 0.07. The Angstrom exponents（α440–870） likewise,have its peak in summer（January） 1.70 ± 0.21 and lowest in early winter（June） 1.38 ± 0.26,while the columnar water vapor（CWV） followed AOD pattern with high values（summer） at the beginning of the year（February, 2.10 ± 0.37 cm） and low values（winter） in the middle of the year（July, 0.66 ± 0.21 cm）. The volume size distribution（VSD） in the fine-mode is higher in the summer and spring seasons, whereas in the coarse mode the VSD is higher in the winter and lower in the summer due to the hygroscopic growth of aerosol *** single scattering albedo（SSA） ranged from 0.85 to 0.96 at 440 nm over PTR for the entire study period. The averaged aerosol radiative forcing（ARF） computed using SBDART model at the top of the atmosphere（TOA） was- 8.78 ± 3.1 W/m2, while at the surface it was- 25.69 ± 8.1 W/m2 leading to an atmospheric forcing of ＋ 16.91 ± 6.8 W/m2, indicating significant heating of the atmosphere with a mean of 0.47 K/day.

关键词： Pretoria AERONET Aerosol optical depth Single scattering albedo radiative forcing

A Modeling Study of the Effects of Direct radiative forcing Due to Carbonaceous Aerosol on the Climate in East Asia

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Advances in Atmospheric Sciences 2009年第1期26卷 57-66页

作者：张华王志立郭品文王在志 Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing 100081 Chinese Academy of Meteorological Sciences Beijing 100081 The College of Atmospheric Science Nanjing University of Information Science and Technology Nanjing 210044

The study investigated the effects of global direct radiative forcing due to carbonaceous aerosol on the climate in East Asia, using the CAM3 developed by NCAR. The results showed that carbonaceous aerosols cause negative forcing at the top of the atmosphere （TOA） and surface under clear sky conditions, but positive forcing at the TOA and weak negative forcing at the surface under all sky conditions. Hence, clouds could change the sign of the direct radiative forcing at the TOA, and weaken the forcing at the surface. Carbonaceous aerosols have distinct effects on the summer climate in East Asia. In southern China and India, it caused the surface temperature to increase, but the total cloud cover and precipitation to decrease. However, the opposite effects are caused for most of northern China and Bangladesh. Given the changes in temperature, vertical velocity, and surface streamflow caused by carbonaceous aerosol in this simulation, carbonaceous aerosol could also induce summer precipitation to decrease in southern China but increase in northern China.

关键词： carbonaceous aerosol radiative forcing CAM3 climate effect in East Asia

The Significant Role of Radiosonde-measured Cloud-base Height in the Estimation of Cloud radiative forcing

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Advances in Atmospheric Sciences 2021年第9期38卷 1552-1565页

作者： Hui XU Jianping GUO Jian LI Lin LIU Tianmeng CHEN Xiaoran GUO Yanmin LYU Ding WANG Yi HAN Qi CHEN Yong ZHANG State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China Meteorological Observation Center China Meteorological AdministrationBeijing 100081China

The satellite-based quantification of cloud radiative forcing remains poorly understood,due largely to the limitation or uncertainties in characterizing cloud-base height(CBH).Here,we use the CBH data from radiosonde measurements over China in combination with the collocated cloud-top height(CTH) and cloud properties from MODIS/Aqua to quantify the impact of CBH on shortwave cloud radiative forcing(SWCRF).The climatological mean SWCRF at the surface(SWCRFSUR),at the top of the atmosphere(SWCRFTOA),and in the atmosphere(SWCRFATM) are estimated to be-97.14,-84.35,and 12.79 W m^(-2),respectively for the summers spanning 2010 to 2018 over *** illustrate the role of the cloud base,we assume four scenarios according to vertical profile patterns of cloud optical depth(COD).Using the CTH and cloud properties from MODIS alone results in large uncertainties for the estimation of SWCRFATM,compared with those under scenarios that consider the ***,the biases of the CERES estimation of SWCRFATM tend to increase in the presence of thick clouds with low ***,the discrepancy of SWCRFATM relative to that calculated without consideration of CBH varies according to the vertical profile of *** a uniform COD vertical profile is assumed,the largest SWCRF discrepancies occur during the early morning or late *** comparison,the two-point COD vertical distribution assumption has the largest uncertainties occurring at noon when the solar irradiation *** findings justify the urgent need to consider the cloud vertical structures when calculating the SWCRF which is otherwise neglected.

关键词： cloud base height radiosonde radiative forcing China climatology

The Impacts of Optical Properties on radiative forcing Due to Dust Aerosol

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Advances in Atmospheric Sciences 2006年第3期23卷 431-441页

作者：王宏石广玉李书严李伟王标黄彦彬 State Key Laboratory of Severe Weather/Center for Numerical Prediction Research State Key Laboratory of Atmospheric and Quaternary Geology Hainan Meteorology and Ecology Institute

There are large uncertainties in the quantitative assessment of radiative effects due to atmospheric dust aerosol. The optical properties contribute much to those uncertainties. The authors perform several sensitivity experiments to estimate the impacts of optical characteristics on regional radiative forcing in this paper. The experiments involve in refractive indices, single scattering aibedo, asymmetry factor and optical depth. An updated dataset of refractive indices representing East Asian dust and the one recommended by the World Meteorology Organization （WMO） are contrastively analyzed and used. A radiative transfer code for solar and thermal infrared radiation with detailed aerosol parameterization is employed. The strongest emphasis is on the refractive indices since other optical parameters strongly depend on it, and the authors found a strong sensitivity of radiative forcing on refractive indices. Studies show stronger scattering, weaker absorption and forward scattering of the East Asian dust particles at solar wavelengths, which leads to higher negative forcing, lower positive forcing and bigger net forcing at the top of the atmosphere （TOA） than that of the WMO dust model. It is also found that the TOA forcings resulting from these two dust models have opposite signs in certain regions, which implies the importance of accurate measurements of optical properties in the quantitative estimation of radiative forcing.

关键词： optical properties dust aerosol radiative forcing

Modeling Study of the Global Distribution of radiative forcing by Dust Aerosol

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Acta meteorologica Sinica 2010年第5期24卷 558-570页

作者：张华马井会郑有飞 Laboratory for Climate Studies National Climate CenterChina Meteorological Administration Pudong New Area Weather Office Shanghai Meteorological Bureau Department of Enviormental Science and Technology Nanjing University of Information Science & Technology

To quantitatively understand the dust aerosol effects on climate change, we calculated the global dis-tribution of direct radiative forcing due to dust aerosol under clear and cloudy skies in both winter and summer, by using an improved radiative transfer model and the global distribution of dust mass concentra-tion given by GADS （Global Aerosol Data Set）. The results show that the global means of the solar forcing due to dust aerosol at the tropopause for winter and summer are -0.48 and -0.50 W m-2, respectively; the corresponding values for the longwave forcing due to dust are 0.11 and 0.09 W m-2, respectively. At the surface, the global means of the solar forcing clue to dust are -1.36 W m-2 for winter and -1.56 W m-2 for summer, whereas the corresponding values for the longwave forcing are 0.27 and 0.23 W m-2, respectively. This work points out that the absolute values of the solar forcing due to dust aerosol at both the tropopause and surface increase linearly with the cosine of solar zenith angle and surface albedo. The solar zenith angle influences both the strength and distribution of the solar forcing greatly. Clouds exert great effects on the direct radiative forcing of dust, depending on many factors including cloud cover, cloud height, cloud water path, surface albedo, solar zenith angle, etc. The effects of low clouds and middle clouds are larger than those of high clouds. The existence of clouds reduces the longwave radiative forcing at the tropopause, where the influences of low clouds are the most obvious. Therefore, the impacts of clouds should not be ignored when estimating the direct radiative forcing due to dust aerosol.

关键词： dust aerosol radiative forcing radiative transfer model surface albedo zenith angle clouds