大气成分与环境气象研究进展.pdf

2022 CAMSAnnual Report91大气成分与环境气象研究进展Advances in Research on Atmospheric Composition and Environmental Meteorology 1 大气成分及相关特性变化观测研究1 Observational studies of atmospheric composition and related properties 1.1 The pathway toward carbon neutrality challenges and countermeasuresChinas solemn commitment to the world to strive for carbon neutrality by 2060 demonstrates the nations determination to take a new development route,different from its impressive achievements during the more than 40 years since 1979.Taking a green,low-carbon,and high-quality development path is also a strong manifestation of Chinas determination to follow its consistent development belief of“conformity with morality,”with its emphasis on multilateral mechanisms and a willingness to make the best possible contribution to global concerns such as adaption to and mitigation of climate change.Through actions that promote carbon neutrality,China also wants to create change in its energy structure,which will be followed by a newly generated industrial structure and socioeconomic status,so as to inspire its citizens to better meet the challenges of the fourth industrial revolution and to take on an active role in this process.Furthermore,achieving the strategic goal of carbon neutrality will have a significant impact on the long-term stability of Chinas development.In the future,China will face many challenges and uncertainties regarding possible scenarios with different emission peak times and carbon emissions by 2050 and the extent of its use of renewables.China is also likely to be confronted with the problem of a portion of carbon dioxide(CO2)from fossil energy combustion remaining in the atmosphere through various efforts by 2050 or 2060,requiring the technology of carbon capture and storage(CCS).The establishment of major science and technology CCS infrastructures is a decisive factor in CCS technological innovation,cost and risk reduction,commercial promotion,and talent training for key technologies.Aside from CCS,carbon capture,utilization,and storage(CCUS)is another means of addressing retained atmospheric CO2 that deserves attention.Significant scientific and technological difficulties and opportunities remain to be overcome or achieved in terms of capture,utilization,and storage,respectively.Energy transition is also a very important technology for the process of replacing traditional fossil energy with renewables,and it needs to be commercialized at a significantly reduced cost.In addition to issues related to achieving carbon neutrality in large-scale industries,there are scientific and technological issues related to achieving carbon neutrality in sectors that are closely linked to social life,such as wastewater treatment.The effects of actions promoting carbon neutrality also need to be promptly monitored,accounted for,and evaluated.Moreover,China needs to learn from and make progress based on the practices and experiences of other countries.For this special issue,six articles and an opinion paper have been chosen to report on the most recent insights into science and technologies aimed at carbon neutrality.大气成分与环境气象 Atmospheric Composition and Environmental Meteorology 科研成果与进展Scientific Achievements and Advances92In this issue,Zhang and Chen propose and compare four carbon-neutral scenarios with different emission peak times and carbon emissions by 2050 using the Integrated MARKAL-EFOM System(TIMES)model of China.They demonstrate that Chinas carbon-emission peak(at 10.310.4 Gt)will occur between 2025 and 2030.By that time,renewables will account for 60%of Chinas total energy consumption(calorific value calculation)and 90%of total electricity generation,and the electrification rate will be close to 60%.The authors emphasize that achieving peak emissions earlier will yield more near-term benefits but will require an accelerated phasing out of coal after 2025 and the widespread deployment of renewables during the subsequent decade.Ma et al.review the development and classification of CCS projects in advanced countries to provide a reference for other countries aiming to deploy and promote CCS projects.Practices in advanced countries show that establishing major science and technology CCS infrastructures has been the dominant factor in CCS technological innovation,cost and risk reduction,commercial promotion,and talent training for key technologies.Lin et al.present a technical perspective on critical aspects of CCUS and propose that chemical absorption requires efficient and low-cost absorbents for its deployment in carbon capture.For carbon utilization,the development of highly active,selective,and stable electrocatalysts and the optimization of electrolyzer design are the future directions for electrochemical conversion.For carbon storage,successful deployment relies on a better understanding of fluid mechanics,geomechanics,and reactive transport.Blunt and Lin suggest applications of multiphase flow in porous media that are relevant to the current energy transition.They propose a framework for designing multiphase displacement that is optimal for flow,trapping,and saturation.This framework can be used to design efficient devices and effective storage schemes that make use of recent advances in non-destructive three-dimensional(3D)imaging,analysis,and modeling.Lam et al.assess the progress and lessons learned from the greenhouse gas(GHG)emissions management of urban water systems in four global cities:Amsterdam,Melbourne,New York City,and Tokyo.The study shows that it is difficult for the water industry to achieve carbon neutrality on its own.A collaborative approach with other sectors is needed when aiming toward a citys carbon-neutrality goal.This approach also involves expanding the usual water industry system boundary to externally tap into engineering and non-engineering opportunities.Liu et al.review conventional annual-based carbon-emission accounting approaches and emerging real-time carbon-emission monitoring technologies.The authors argue that real-time carbon-emission monitoring technology would strongly support the carbon-neutrality strategy in China and present a global near-real-time carbon-emission framework.Wei et al.summarize the priorities,perspectives,and scientific and strategic demands involved in achieving a carbon peak and carbon neutrality by reviewing 1105 publications on these two carbon-emission-reduction goals between 1995 and 2020.Based on a full review of the research status in this field,the authors propose theoretical insights and practical countermeasures that would facilitate achieving a carbon-neutral future.We believe that these articles can provide readers with information on recent developments in science,technology,and systems management for achieving the goals of carbon neutrality and a sustainable future for our planet.(Zhang,Xiaoye)1.2 Turbulent transport dissimilarities of particles,momentum,and heatThe turbulent transport of particles is normally assumed to be similar to the momentum(or heat)transport,both in observations and simulations.However,observations from the boundary layer reinforcement 2022 CAMSAnnual Report93experiment conducted at the Pingyuan County Meteorological Bureau,Shandong Province,China,showed dissimilar turbulent transports for momentum,heat,and particles.Our results reveal the prevalence of ejection and sweep motions in the transport of momentum and heat but not in that of particles.For momentum transport,sweep motion is more efficient,and the contribution of ejection(sweeps)motion is higher during the day(night)for heat transport.Momentum transport may be affected by pollutants during heavy pollution episodes(HPEs),whereas heat transport is affected by pollutants at night during HPEs.The sink/source differences lead to differences in particle transport for different HPEs.Furthermore,the momentum motion does not transport heat and particles in the same manner,particularly during HPEs.Compared to heat and momentum transport,the transport of particles is not significantly affected by stability.The turbulent transport of momentum is often smaller than that of particles and heat.Therefore,certain dissimilarities exist in the turbulent transport of momentum,heat,and particles.Overall,these findings found by the observations shed some light on the turbulent transport of particles in mesoscale models,and the turbulent transport dissimilarities between momentum,heat,and particles have an important impact on correcting and obtaining an accurate particle flux.(Jia Wenxing,Zhang Xiaoye)1.3 Superimposed effects of typical local circulations driven by mountainous topography and aerosol-radiation interaction on heavy haze in the Beijing-Tianjin-Hebei central and southern plains in winterAlthough Chinas air quality has substantially improved in recent years due to the vigorous emission reduction,the Beijing-Tianjin-Hebei(BTH)region,especially its central and southern plains at the eastern foot of the Taihang Mountains,has been the most polluted area in China with persistent and severe haze in winter.Combining meteorology-chemistry coupled model simulations and multiple observations,this study explored the causes of several heavy haze events in this area in January 2017,focusing on local circulations related to mountain terrain.The study results showed that on weather scale,the configuration of the upper,middle,and lower atmosphere provided favorable weather and water vapor transport conditions for the development of haze pollution.Under the weak weather-scale systems,local circulation played a dominant role in the regional distribution and extreme values of PM2.5.Influenced by the Taihang and Yanshan Mountains,vertical circulations and wind convergence zone were formed between the plain and mountain slopes.The vertical distribution of pollutants strongly depended on the intensity and location of the circulation.Strong and low circulation was more unfavorable to the vertical diffusion and horizontal transport of near-surface pollutants.More importantly,we found that aerosol-radiation interaction(ARI)significantly amplified the impacts of local vertical circulations on heavy haze by two mechanisms.First,ARI strengthened the vertical circulations at the lower levels,with the zonal wind speeds increasing by 0.20.8 m s1.Meanwhile,ARI could cause a substantial downward shift of the vertical circulations(about 100 m).Second,ARI weakened the horizontal transport of pollutants by reducing the westerly winds below 300 m and enhancing the wind convergence below 1000 m.Under these two mechanisms,pollutants could only recirculate in a limited space.This superposition of typical local circulation and ARI eventually contributed to the accumulation of pollutants and the consequent deterioration of haze pollution in the region.(Peng Yue,Wang Hong,Zhang Xiaoye)1.4 Long-term trend of new particle formation events in the Yangtze River Delta,China and its influencing factors:7-year dataset analysisTo evaluate the influence of anthropogenic emission reductions since 2013 in China,a long-term trend analysis of the particle number size distribution(PNSD)and new particle formation(NPF)events in the Yangtze River Delta(YRD)region was conducted based on the PNSD measurement(diameter ranging from 3 to 850 nm)at the Linan(LAN)regional background station from 2013 to 2019.A modified Mann-Kendall 科研成果与进展Scientific Achievements and Advances94test and a Theil-Sen estimator were used to calculate the overall trend of particle number concentrations in different modes and the relevant influencing factors.We observed a significant decreasing trend in the Aitken and accumulation mode number concentrations,with annual decrease rates of approximately 5.6%and 8.2%,respectively,resulting in an approximately 6.0%decline in total particles annually.However,the nucleation mode particle number concentration showed no significant trend from 2013 to 2016,but an increasing trend from 2016 to 2019,which was related to the NPF events occurrence frequency.The regional NPF events of“banana shape”accounted for an increasing fraction of all NPF events.As a key parameter influencing the NPF event,the condensation sink decreased by approximately 63%from 2013 to 2019.Moreover,the estimated sulfuric acid concentration decreased by approximately 50%,with a higher reduction rate occurring during 20132016 as a result of the effective SO2 reduction.Surface meteorological factors(including the air temperature,relative humidity,air pressure,and wind)and the air masses origin were found to play minor roles in the long-term trend of NPF events.As PNSD and NPF events are closely related to changes in the particle emissions and regional air pollution levels,studies concerning PNSD and NPF are necessary to provide important information regarding air quality improvements and evaluating the efficacy of climate change mitigation strategies.(Shen Xiaojing,Sun Junying,Ma Qianli,Zhang Yangmei,Zhong Junting,Yue Yi,Xia Can,Hu Xinyao,Zhang Sinan,Zhang Xiaoye)1.5 The significant contribution of small-sized and spherical aerosol particles to the decreasing trend in total aerosol optical depth over land from 2003 to 2018The optical and microphysical properties of aerosols remain one of the greatest uncertainties associated with evaluating the climate forcing attributed to aerosols.Although the trends in aerosol optical depth(AOD)at global and regional scales have been widely examined,little attention has been paid to the trends in type-dependent AODs related to aerosol particle properties.Here,using the aerosol optical component dataset from the multi-angle imaging spectroradiometer(MISR)instrument,we investigate decadal-scale trends in total aerosol loading as well as AODs for five aerosol components by particle size and morphology during 20032018 over land.Relationships between the total AOD(TAOD)trends and type-dependent AOD changes were examined,and the relative contribution of each type-dependent AOD to the overall TAOD trends was quantified.By dividing the TAOD values into four different aerosol pollution levels(APLs)with splits at 0.15,0.40,and 0.80,we further explored the relationships between TAOD changes and interannual variations in the frequency-of-occurrences(FoOs)of these APLs.Long-term trends in FoOs in the different APLs show that there was a significant improvement in air quality between 2003 and 2018 in most land areas,except South Asia,corresponding to a shift from lightly polluted to clean conditions.However,the effects of different APLs on TAOD changes are regionally dependent and their extent of correlation varied spatially.Moreover,we observed that the annual mean TAOD has decreased by 0.47%yr1 over land since 2003(P 0.05).This significant reduction was mainly attributed to the continued reduction in small-sized(0.7 mm diameter)AOD(SAOD)(0.74%yr1)and spherical AOD(SPAOD)(0.46%yr1).Statistical analysis shows that SAOD and SPAOD respectively