A Review of Atmospheric Chemistry Research in China: Photochemical Smog, Haze Pollution, and Gas-Aerosol Interactions

In this paper we present a review of atmospheric chemistry research in China over the period 2006-2010, focusing on tropospheric ozone, aerosol chemistry, and the interactions between trace gases and aerosols in the polluted areas of China. Over the past decade, China has suffered severe photochemical smog and haze pollution, especially in North China, the Yangtze River Delta, and the Pearl River Delta. Much scientific work on atmospheric chemistry and physics has been done to address this large-scale, complex environmental problem. Intensive field experiments, satellite data analyses, and model simulations have shown that air pollution is significantly changing the chemical and physical characters of the natural atmosphere over these parts of China. In addition to strong emissions of primary pollutants, photochemical and heterogeneous reactions play key roles in the formation of complex pollution. More in-depth research is recommended to reveal the formation mechanism of photochemical smog and haze pollution and their climatic effects at the urban, regional, and global scales.     

The Relative Impact of Regional Scale Land Cover Change and Increasing CO2 over China

A series of 17-yr equilibrium simulations using the NCAR CCM3 (T42 resolution) were performed to investigate the regional scale impacts of land cover change and increasing CO2 over China. Simulations with natural and current land cover at CO2 levels of 280,355, 430, and 505 ppmv were conducted. Results show statistically significant changes in major climate fields (e.g. temperature and surface wind speed) on a 15-yr average following land cover change. We also found increases in the maximum temperature and in the diurnal temperature range due to land cover change. Increases in CO2 affect both the maximum and minimum temperature so that changes in the diurnal range are small. Both land cover change and CO2 change also impact the frequency distribution of precipitation with increasing CO2 tending to lead to more intense precipitation and land cover change leading to less intense precipitation-indeed, the impact of land cover change typically had the opposite effect versus the impacts of CO2. Our results provide support for the inclusion of future land cover change scenarios in long-term transitory climate inodelling experiments of the 21st Century. Our results also support the inclusion of land surface models that can represent future land cover changes resulting from an ecological response to natural climate variability or increasing CO2. Overall, we show that land cover change can have a significant impact on the regional scale climate of China, and that regionally, this impact is of a similar magnitude to increases in CO2 of up to about 430 ppmv. This means that that the impact of land cover change must be accounted for in detection and attribution studies over China.     

Numerical Simulation of Long-Term Climate Change in East Asia

A 10-yr regional climate simulation was performed using the fifth-generation PSU/NCAR Mesoscale Model Version 3 (MM5V3) driven by large-scale NCEP/NCAR reanalyses. Simulations of winter and summer mean regional climate features were examined against observations. The results showed that the model could well simulate the 10-yr winter and summer mean circulation, temperature, and moisture transport at middle and low levels. The simulated winter and summer mean sea level pressure agreed with the NCAR/NCEP reanalysis data. The model could well simulate the distribution and intensity of winter mean precipitation rates as well as the distribution of summer mean precipitation rates, but it overestimated the summer mean precipitation over North China. The model's ability to simulate the regional climate change in winter was superior to that in summer. In addition, the model could simulate the inter-annual variation of seasonal precipitation and surface air temperature. Geopotential heights and temperature at middle and high levels between simulations and observations exhibited high anomaly correlation coefficients. The model also showed large variability to simulate the regional climate change associated with the El Nino events. The MM5V3 well simulated the anomalies of summer mean precipitation in 1992 and 1995, while it demonstrated much less ability to simulate that in 1998. Generally speaking, the MM5V3 is capable of simulating the regional climate change, and could be used for long-term regional climate simulation.     

MM5 Simulations of the China Regional Climate During the LGM. Ⅱ： Influence of Change of Land Area,Vegetation, and Large-scale Circulation Background

Using a regional climate model MM5 nested to an atmospheric global climate model CCM3, a series of simulations and sensitivity experiments have been performed to investigate the relative LGM climate response to changes of land-sea distribution, vegetation, and large-scale circulation background over China. Model results show that compared with the present climate, the fluctuations of sea-land distribution in eastern Asia during the LGM result in the temperature decrease in winter and increase in summer. It has significant impact on the temperature and precipitation in the east coastal region of China. The impact on precipitation in the east coastal region of China is the most significant one, with 25%-50% decrease in the total precipitation change during the LGM. On the other hand, the changes in sea-land distribution have less influence on the climate of inland and western part of China. During the LGM, significant changes in vegetation result in temperature alternating with winter increase and summer decrease, but differences in the annual mean temperature are minor. During the LGM, the global climate, i.e., the large-scale circulation background has changed significantly. These changes have significant influences on temperature and precipitation over China. They result in considerable temperature decreases in this area, and direct the primary patterns and characteristics of temperature changes. Results display that, northeastern China has the greatest temperature decrease, and the temperature decrease in the Tibetan Plateau is larger than in the eastern part of China located at the same latitude. Moreover, the change of large-scale circulation background also controls the pattern of precipitation change. Results also show that, most of the changes in precipitation over western and northeastern parts of China are the consequences of changing large-scale circulation background, of which 50%-75% of precipitation changes over northern and eastern China are the results of changes in large-scale circulation backgrou     

Numerical Simulation of Regional Climate Change under IPCC A2 Scenario in China

Regional climate change in China under the IPCC A2 Scenario, was simulated for continuous 10-yr period by the MM5V3, using the output of an IPCC A2 run from CISRO Mark 3 climate system model as lateral and surface boundary conditions. The regional climate change of surface air temperature, precipitation, and circulation were analyzed. The results showed that （1） the distribution of mean circulation, surface air temperature, and precipitation was reproduced by the MM5V3. The regional climate model was capable to improve the regional climate simulation driven by GCM. （2） The climate change simulation under the IPCC A2 Scenario indicated that the surface air temperature in China would increase in the future, with a stronger trend in winter and the increasing magnitude from the south to the north. The precipitation distribution would appear a distinct change as well. Annual mean precipitation would remarkably increase in Northeast China, Yangtze and Huaihe River Valley, and the south area of the valley. Meanwhile, rainfall would show a decreasing trend in partial areas of North China, and many regions of Southwest and Northwest China.     

Detection, Causes and Projection of Climate Change over China： An Overview of Recent Progress

This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years.It is shown that observed climate change in China bears a strong similarity with the global average.The country-averaged annual mean surface air temperature has increased by 1.1℃over the past 50 years and 0.5-0.8℃over the past 100 years,slightly higher than the global temperature increase for the same periods.Northern China and winter have experienced the greatest increases in surface air temperature.Although no significant trend has been found in country-averaged annual precipitation, interdecadal variability and obvious trends on regional scales are detectable,with northwestern China and the mid and lower Yangtze River basin having undergone an obvious increase,and North China a severe drought.Some analyses show that frequency and magnitude of extreme weather and climate events have also undergone significant changes in the past 50 years or so. Studies of the causes of regional climate change through the use of climate models and consideration of various forcings,show that the warming of the last 50 years could possibly be attributed to an increased atmospheric concentration of greenhouse gases,while the temperature change of the first half of the 20th century may be due to solar activity,volcanic eruptions and sea surface temperature change.A significant decline in sunshine duration and solar radiation at the surface in eastern China has been attributed to the increased emission of pollutants. Projections of future climate by models of the NCC(National Climate Center,China Meteorological Administration)and the IAP(Institute of Atmospheric Physics,Chinese Academy of Sciences),as well as 40 models developed overseas,indicate a potential significant warming in China in the 21st century,with the largest warming set to occur in winter months and in northern China.Under varied emission scenarios,the country-averaged annual mean temperature is projected to increase by 1.5-2.1℃by 2020,2.3-3.3℃by 2050, and by 3.9-6.0℃by 2100,in comparison to the 30-year average of 1961 1990.Most models project a 10% 12% increase in annual precipitation in China by 2100,with the trend being particularly evident in Northeast and Northwest China,but with parts of central China probably undergoing a drying trend.Large uncertainty exists in the projection of precipitation,and further studies are needed.Furthermore,anthropogenic climate change will probably lead to a weaker winter monsoon and a stronger summer monsoon in eastern Asia.     

Atmospheric Environmental Capacity of SO2 in Winter over Lanzhou in China： A Case Study

The total emission control method based on atmospheric environmental capacity is the most effective in air pollution mitigation. The atmospheric environmental capacities of SO2 on representative days over Lanzhou are estimated using the numerical models RAMS, HYPACT and a linear programming model, according to the national ambient air quality standard of China （NAAQSCHN）. The results show that the fields of meteorological elements and SO2 simulated by the models agree reasonably well with observations. The atmospheric environmental capacity of SO2 over Lanzhou is around 111.7 × 10^3 kg d^-1, and in order to meet the air quality level Ⅱ of the NAAQSCHN, SO2 emissions need to be reduced by 20%.     

GCM STUDIES ON ANTHROPOGENIC CLIMATE CHANGE IN CHINA

Impacts of human activities on climate change as simulated by the general circulation models(GCMs)in China for the recent ten years have been summarized and reviewed in this paper.Theresearches show that it might be getting warmer over China due to the greenhouse effects.Theatmospheric circulation and precipitation also might be changed due to the greenhouse effects.Theassessments and evaluations of the models over the globe and China have also been presented in thispaper.     

Progress in the Development and Application of Climate Ocean Models and Ocean-Atmosphere Coupled Models in China

A review is presented about the development and application of climate ocean models and oceanatmosphere coupled models developed in China as well as a review of climate variability and climate change studies performed with these models. While the history of model development is briefly reviewed, emphasis has been put on the achievements made in the last five years. Advances in model development are described along with a summary on scientific issues addressed by using these models. The focus of the review is the climate ocean models and the associated coupled models, including both global and regional models, developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences. The progress of either coupled model development made by other institutions or climate modeling using internationally developed models also is reviewed.     

A Numerical Simulation Study of Impacts of Historical Land-Use Changes on the Regional Climate in China Since 1700

By using the improved regional climate model (BCC_RegCM1.0), a series of modeling experiments are undertaken to investigate the impacts of historical land-use changes (LUCs) on the regional climate in China. Simulations are conducted for 2 years using estimated land-use for 1700, 1800, 1900, 1950, and 1990. The conversion of land cover in these periods was extensive over China, where large areas were altered from forests to either grass or crops, or from grasslands to crops. Results show that, since 1700, historical LUCs have significant effects on regional climate change, with rainfall increasing in the middle and lower reaches of the Yangtze River Basin, Northwest China, and Northeast China, but decreasing by different degrees in other regions. The air temperature shows significant warming over large areas in recent hundred years, especially from 1950 to 1990, which is consistent with the warming caused by increasing greenhouse gases. On the other hand, historical LUCs have obvious effects on mean circulation, with the East Asian winter and summer monsoonal flows becoming more intensive, which is mainly attributed to the amplifled temperature difference between ocean and land due to vegetation change. Thus, it would be given more attention to the impacts of LUCs on regional climate change.     

Climatic effects of air pollutants over china: A review

Tropospheric ozone(O3) and aerosols are major air pollutants in the atmosphere. They have also made significant contributions to radiative forcing of climate since preindustrial times. With its rapid economic development, concentrations of air pollutants are relatively high in China; hence, quantifying the role of air pollutants in China in regional climate change is especially important. This review summarizes existing knowledge with regard to impacts of air pollutants on climate change in China and defines critical gaps needed to reduce the associated uncertainties. Measured monthly, seasonal, and annual mean surface-layer concentrations of O3 and aerosols over China are compiled in this work, with the aim to show the magnitude of concentrations of O3 and aerosols over China and to provide datasets for evaluation of model results in future studies. Ground-based and satellite measurements of O3 column burden and aerosol optical properties, as well as model estimates of radiative forcing by tropospheric O3 and aerosols are summarized. We also review regional and global modeling studies that have investigated climate change driven by tropospheric O3and/or aerosols in China; the predicted sign and magnitude of the responses in temperature and precipitation to O3/aerosol forcings are presented. Based on this review, key priorities for future research on the climatic effects of air pollutants in China are highlighted.     

中国的PM2.5和对流层臭氧及污染物排放控制对策的综合分析

本文首先对中国PM2.5和近地面臭氧浓度的观测进行了简要的综述;并利用2010-2013年全球对流层臭氧的卫星观测数据给出了对流层臭氧浓度在全球和中国地区的分布特征,其平均值分别为29.78 DU和33.97 DU。然后,利用一个气溶胶大气化学-全球气候双向耦合模式模拟了中国地区PM2.5的浓度分布和季节变化,其年平均值为0.51×10^-8 kg/m³。在此基础上又分析了5种典型气溶胶对PM2.5总浓度在不同季节的贡献。结合IPCC第五次评估报告（AR5）,讨论了气溶胶和温室气体及其前体物的排放与辐射强迫的联系,以及减排大气臭氧前体物和气溶胶颗粒物质（PM）对气候变化的可能影响。指出减排臭氧前体物对气候的影响还不完全清楚,对短寿命的温室气体和黑碳气溶胶的减排是一种短期（未来50年）的辅助措施;为了保证全球平均温度增长不超过2℃,减少二氧化碳的排放仍是我们需要坚持的长期战略。短期和长期的减排战略对于保护环境和减缓气候变化都是至关重要的。     

Seasonal to interannual prediction of air pollution in China:Review and insight

复合型大气污染对中国环境,健康和经济存在巨大的不利影响.2013年以来的减排措施有效改善了空气质量.目前,我国已进入大气污染与气候变化协同治理的关键阶段.在季节-年际尺度上,对大气污染(霾,臭氧和沙尘暴)的准确预测可以为有关部门的减排措施提供有效的科技技撑.近年来,全球科学家在理解中国气候变化,大气污染变率及相关物理机...     

秦皇岛2019年冬季重污染过程PM2.5来源数值模拟

秦皇岛地处河北省东北部,是环渤海重要的港口城市,在近几年京津冀地区减排效果较好的情况下,于2019年1月出现了多次持续细颗粒物（PM2.5）污染过程。因此本文利用耦合了数值源解析模块ISAM（Integrated Source Apportionment Method）的区域空气质量模式RAMS-CMAQ（Regional Atmospheric Modeling System–Community Multiscale Air Quality）,对2019年1月秦皇岛地区PM2.5进行模拟,并将PM2.5质量浓度高于（低于）75 μg m－3的时段划分为污染（清洁）时段,分别探讨了两个时段本地排放源对秦皇岛市PM2.5质量浓度的贡献情况,并且进一步探讨了秦皇岛各区县及外地排放源对秦皇岛市4个国控环境监测站点（第一关站、北戴河站、市监测站、建设大厦站）PM2.5质量浓度的区域传输特征。结果表明,秦皇岛地区PM2.5质量浓度整体呈“南高北低”式分布。清洁时段,PM2.5质量浓度受本地贡献较大,青龙县、卢龙县大部分地区贡献为40%～50%,海港区、抚宁区、北戴河区、第一关区及昌黎县大部分地区贡献在60%以上;4个国控环境监测站点受跨界输送贡献占34.7%～41.6%。污染时段,秦皇岛市本地贡献相对于清洁时段整体下降10%左右,当地大气污染受到跨界区域传输影响增加;而在4个国控站中,北戴河站、第一关站受到跨界输送贡献分别下降1.0%和2.3%;市监测站、建设大厦站受到跨界输送贡献分别上升2.9%和2.0%。     

四川盆地大气气溶胶污染时空变化的地形影响研究进展

四川盆地作为我国一个特殊的大气气溶胶污染区域,亟待厘清其大气污染时空变化与独特盆地地形影响相关机理。本文综述了近年来一系列相关研究成果,包括:（1）揭示了四川盆地大气环境变化中大地形影响作用,青藏高原东侧区域气溶胶空间分布“避风港”效应,以及大地形热力强迫对盆地空气质量变化的“气候调节”影响; （2）探明了四川盆地大气边界层结构对大气气溶胶变化的影响,冬季重霾期间大气边界层垂直结构变化特征及其相关PM_2.5物理化学特性;（3）明晰了大气气溶胶在四川盆地暴雨过程中的重要作用机理,以及四川盆地气溶胶高污染分布导致的降水分布型态的气候变化。这些研究提升了四川盆地气溶胶污染形成机理及大地形对大气环境变化影响效应的科学认识,并表明未来应该深入研究四川盆地地形背景下独特大气边界层结构,人为与自然源排放和环境大气物理-化学过程变化。      

Better air for better health: Forging synergies in policies for energy access,climate change and air pollution

Air pollution and its related health impacts are a global concern. This paper addresses how current policies on air pollution, climate change and access to clean cooking fuels can effectively reduce both outdoor and household air pollution and improve human health. A state of the art modeling framework is used that combines an integrated assessment model and an atmospheric model to estimate the spatial extent and distribution of outdoor air pollution exposures. Estimates of household energy access and use are modeled by accounting for heterogeneous household energy choices and affordability constraints for rural and urban populations spanning the entire income distribution. Results are presented for 2030 for a set of policy scenarios on air pollution, climate change and energy access and include spatially explicit emissions of air pollutants; ambient concentrations of PM2.5; and health impacts in terms of disability adjusted life years (DALYs) from both ambient and household air pollution. The results stress the importance of enforcing current worldwide air quality legislation in addressing the impacts of outdoor air pollution. A combination of stringent policies on outdoor air pollution, climate change and access to clean cooking fuels is found to be effective in achieving reductions in average ambient PM2.5 exposures to below World Health Organization recommended levels for a majority of the world's population and results in a significant decline in the global burden of disease from both outdoor and household air pollution.     

我国霾和光化学污染观测研究进展

霾和光化学污染已成为我国最严重的环境气象灾害,受到政府和公众广泛关注。针对我国的环境气象问题,国内外科研人员开展了大量研究工作,发表了一系列的研究成果。该文对近年来我国霾和光化学污染的观测、分析和影响研究方面的文献进行综述,为将来相关研究提供基础。在霾污染方面,主要回顾了霾的现象与判别、组成与来源、影响霾的气象因素、霾的长期趋势等方面的研究进展。在光化学污染方面,主要回顾了污染的特征与水平、污染的区域化、臭氧垂直分布、地面臭氧影响因素、臭氧污染发展趋势等方面的研究进展。此外,还概括了霾和光化学污染危害研究主要成果,在文献综述的基础上,提出了未来研究中值得关注的几方面问题,包括进一步加强霾和雾的科学判识方法、污染物相互作用、污染-气象-化学-生态间耦合效应研究,特别关注光化学污染发展态势,加强长期观测资料的积累、分析与应用等。     

Future air pollution in the Shared Socio-economic Pathways

Emissions of air pollutants such as sulfur and nitrogen oxides and particulates have significant health impacts as well as effects on natural and anthropogenic ecosystems. These same emissions also can change atmospheric chemistry and the planetary energy balance, thereby impacting global and regional climate. Long-term scenarios for air pollutant emissions are needed as inputs to global climate and chemistry models, and for analysis linking air pollutant impacts across sectors. In this paper we present methodology and results for air pollutant emissions in Shared Socioeconomic Pathways (SSP) scenarios. We first present a set of three air pollution narratives that describe high, central, and low pollution control ambitions over the 21st century. These narratives are then translated into quantitative guidance for use in integrated assessment models. The resulting pollutant emission trajectories under the SSP scenarios cover a wider range than the scenarios used in previous international climate model comparisons. In the SSP3 and SSP4 scenarios, where economic, institutional and technological limitations slow air quality improvements, global pollutant emissions over the 21^st century can be comparable to current levels. Pollutant emissions in the SSP1 scenarios fall to low levels due to the assumption of technological advances and successful global action to control emissions.     

汾渭平原CUACE模式空气质量预报性能的检验订正及环境评估

利用2019年1—6月地面环境监测资料和PM_2.5气象条件评估指数，结合滚动偏差订正方法，对汾渭平原CUACE空气质量预报产品进行了检验订正，并对气象条件和污染减排影响进行了评估。结果表明：CUACE模式对空气质量指数(AQI)、PM_2.5和SO₂浓度预报值较接近观测值，PM₁₀、CO和NO₂预报值小于观测值，O₃预报值大于观测值；对首要污染物O₃和PM_2.5及重度和严重等级污染的预报的TS评分最高，漏报率和空报率最小，预报偏差最接近1；滚动偏差订正方法对改善CUACE空气质量预报效果较为明显，尤其是对PM₁₀、O₃和NO₂改善最为明显；汾渭平原2019年上半年气象条件变化使PM_2.5浓度较2018年同期和过去5年同期分别上升了18.26%和11.18%，减排措施使PM_2.5浓度较2018年同期和过去5年...