Modeling Study of Aerosol Indirect Effectson Global Climate with an AGCM

Aerosol indirect effects （AIEs） on global climate were quantitatively investigated by introducing aerosol–cloud interaction parameterizations for water stratus clouds into an AGCM （BCC AGCM2.0.1）, which was developed by the National Climate Center of the China Meteorological Administration. The study yielded a global annual mean of -1.14 W m^-2 for the first indirect radiative forcing （IRF）, with an obvious seasonal change. In summer, large forcing mainly occurred in mid to high latitudes of the Northern Hemisphere, whereas in winter, large values were found at 60°S. The second indirect effect led to global annual mean changes in net shortwave flux of -1.03 W m^-2 at the top of the atmosphere （TOA）, which was relatively significant in mid-latitude regions of both hemispheres. The total AIE reduced the global annual means of net shortwave flux at the TOA and of surface temperature by 1.93 W m^-2 and 0.12 K, respectively. Change in surface temperature induced by the total AIE was clearly larger in the Northern Hemisphere （-0.23 K） than in the Southern Hemisphere, where changes were negligible. The interhemispheric asymmetry in surface cooling resulted in significant differences in changes of the interhemispheric annual mean precipitation rate, which could lead to a tendency for the ITCZ to broaden. The total AIE decreased the global annual mean precipitation rate by 0.055 mm df^-1.

First Surface-based Estimation of the Aerosol Indirect Effect over a Site in Southeastern China

The deployment of the U.S. Atmospheric Radiation Measurement mobile facility in Shouxian from May to December 2008 amassed the most comprehensive set of measurements of atmospheric, surface, aerosol, and cloud variables in China. This deployment provided a unique opportunity to investigate the aerosol-cloud interactions, which are most challenging and, to date, have not been examined to any great degree in China. The relationship between cloud droplet effective radius （CER） and aerosol index （AI） is very weak in summer because the cloud droplet growth is least affected by the competition for water vapor. Mean cloud liquid water path （LWP） and cloud optical depth （COD） significantly increase with increasing AI in fall. The sensitivities of CER and LWP to aerosol loading increases are not significantly different under different air mass conditions. There is a significant correlation between the changes in hourly mean AI and the changes in hourly mean CER, LWP, and COD. The aerosol first indirect effect （FIE） is estimated in terms of relative changes in both CER （FIEcER） and COD （FIEcoD） with changes in AI for different seasons and air masses. FIEcoD and FIEcER are similar in magnitude and close to the typical FIE value of - 0.23, and do not change much between summer and fall or between the two different air mass conditions. Similar analyses were done using spaceborne Moderate Resolution Imaging Spectroradiometer data. The satellite-derived FIE is contrary to the FIE estimated from surface retrievals and may have large uncertainties due to some inherent limitations.

Aerosol Indirect Effects on Warm Clouds in the Grid-Point Atmospheric Model of IAP LASG(GAMIL)

Aerosol indirect effects on warm clouds are estimated in the Grid-point Atmospheric Model of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics(IAP LASG)(GAMIL) with a new two-moment cloud microphysics scheme using two different physically-based aerosol activation parameterizations:Abdul-Razzak and Ghan,and Nenes and Seinfeld.The annual global mean changes in shortwave cloud forcing from preindustrial times to present day(a measure of the aerosol indirect effects) estimated from these two parameterizations are remarkably similar:0.76 W m?2 with the Abdul-Razzak and Ghan parameterization,and 0.78 W m?2 with the Nenes and Seinfeld parameterization.Physically-based parameterizations can provide robust representations of aerosol effects on droplet nucleation,meaning that aerosol activation is no longer the most uncertain factor in modeling aerosol indirect effects.

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

This study investigated the second indirect climatic effect of anthropogenic aerosols,including sulfate,organic carbon(OC) ,and black carbon(BC) ,over East Asia.The seasonal variation of the climatic response to the second indirect effect was also characterized.The simulation period for this study was 2006.Due 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 average.Both 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 district.The regional and annual mean change in ground temperature reached-0.2 K over eastern China.In all seasons except summer,precipitation generally decreased in most areas north of the Yangtze River,whereas precipitation changed little in South China.Precipitation changed most in summer,with alternating bands of increasing(～40 mm) and decreasing(～40 mm) precipitation appearing in eastern China.Precipitation decreased by 1.5-40 mm over large areas of Northeast China and the Huabei Plain.The domain and annual mean change in precipitation was approximately-0.3 mm over eastern China.The maximum reduction in precipitation occurred in summer,with mean absolute and relative changes of-1.2 mm and-3.8%over eastern China.This study revealed considerable climate responses to the second indirect effect of aerosols over specific regions of China.

Indirect effects among biodiversity loss of mutualistic ecosystems

Drastic reduction in biodiversity has been a severe threat to ecosystems,which is exacerbated when losing few species leads to disastrous and even irreparable consequences.Therefore,revealing the mechanism underlying biodiversity loss is of uttermost importance.In this study,we show that abundant indirect interactions among mutualistic ecosystems are critical in determining species’status.Combining topological and ecological characteristics,we propose an indicator derived from a dynamic model to identify keystone species and quantify their influence,which outperforms widely-used indicators like degree in realistic and simulated networks.Furthermore,we demonstrate that networks with high modularity,heterogeneity,biodiversity,and less intimate interactions tend to have larger indirect effects,which are more amenable in predicting decline of biodiversity with the proposed indicator.These findings shed some light onto the influence of apposite biodiversities,paving the way from complex network theory to ecosystem protection and restoration.

Indirect effects among biodiversity loss of mutualistic ecosystems

Drastic reduction in biodiversity has been a severe threat to ecosystems,which is exacerbated when losing few species leads to disastrous and even irreparable consequences.Therefore,revealing the mechanism underlying biodiversity loss is of uttermost importance.In this study,we show that abundant indirect interactions among mutualistic ecosystems are critical in determining species’status.Combining topological and ecological characteristics,we propose an indicator derived from a dynamic model to identify keystone species and quantify their influence,which outperforms widely-used indicators like degree in realistic and simulated networks.Furthermore,we demonstrate that networks with high modularity,heterogeneity,biodiversity,and less intimate interactions tend to have larger indirect effects,which are more amenable in predicting decline of biodiversity with the proposed indicator.These findings shed some light onto the influence of apposite biodiversities,paving the way from complex network theory to ecosystem protection and restoration.

Indirect Radiative Forcing and Climatic Effect of the Anthropogenic Nitrate Aerosol on Regional Climate of China

The regional climate model （RegCM3） and a tropospheric atmosphere chemistry model （TACM） were coupled, thus a regional climate chemistry modeling system （RegCCMS） was constructed, which was applied to investigate the spatial distribution of anthropogenic nitrate aerosols, indirect radiative forcing, as well as its climatic effect over China. TACM includes the thermodynamic equilibrium model ISORROPIA and a condensed gas-phase chemistry model. Investigations show that the concentration of nitrate aerosols is relatively high over North and East China with a maximum of 29μg m-3 in January and 8 μg m-3 in July. Due to the influence of air temperature on thermodynamic equilibrium, wet scavenging of precipitation and the monsoon climate, there are obvious seasonal differences in nitrate concentrations. The average indirect radiative forcing at the tropopause due to nitrate aerosols is -1.63 W m 2 in January and -2.65 W m 2 in July, respectively. In some areas, indirect radiative forcing reaches -10 W m-2. Sensitivity tests show that nitrate aerosols make the surface air temperature drop and the precipitation reduce on the national level. The mean changes in surface air temperature and precipitation are 0.13 K and -0.01 mm d-1 in January and -0.09 K and -0.11 mm d-1 in July, respectively, showing significant differences in different regions.

Analytical Studies of the Cloud Droplet Spectral Dispersion Influence on the First Indirect Aerosol Effect

Atmospheric aerosols （acting as cloud condensation nuclei） can enhance the cloud droplet number concentration and reduce the cloud droplet size, and in turn affect the cloud optical depth, as well as the cloud albedo, and thereby exert a radiative influence on climate （the first indirect aerosol effect）. In this paper, based on various relationships between cloud droplet spectral dispersion （c） and cloud droplet number concentration （Nc）, we analytically derive the corresponding expressions of the cloud radiative forcing induced by changes in the cloud droplet number concentration. Further quantitative evaluation indicates that the cloud radiative forcing induced by aerosols for the different ^-Nc relationships varies from -29.1% to 25.2%, compared to the case without considering spectral dispersion （e = 0）. Our results suggest that an accurate description of e - Nc relationships helps to reduce the uncertainty of the first indirect aerosol effect and advances our scientific understanding of aerosol-cloud-radiation interactions.

An improved recommendation algorithm via weakening indirect linkage effect

We propose an indirect-link-weakened mass diffusion method（IMD）, by considering the indirect linkage and the source object heterogeneity effect in the mass diffusion（MD） recommendation method. Experimental results on the MovieLens, Netflix, and RYM datasets show that, the IMD method greatly improves both the recommendation accuracy and diversity, compared with a heterogeneity-weakened MD method（HMD）, which only considers the source object heterogeneity. Moreover, the recommendation accuracy of the cold objects is also better elevated in the IMD than the HMD method. It suggests that eliminating the redundancy induced by the indirect linkages could have a prominent effect on the recommendation efficiency in the MD method.

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

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 parameterization.The first indirect radiative forcing was negative and ranged from-9-0 W m-2 in the domain.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 winter.Organic carbon (OC) aerosols were more abundant in winter than in summer,whereas the sulfate concentration during summer was much higher than during winter.The 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 important.The regional mean indirect radiative forcings were-0.73 W m-2 and-0.41 W m-2 in summer and winter,respectively.The surface cooling caused by indirect effects was more obvious in winter than that in summer.The 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 Rivers.In 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.

On the parameters for electrocaloric effect predicted by indirect method

The influences of specific heat capacity CP, temperature step ？T, electric field step ？E, and initial electric field E1 on predicted electrocaloric（EC） temperature ？T of monodomain Ba TiO3 are examined by combining the Maxwell equation and phenomenological theory. Since the procedure is similar to indirect measurement of the EC effect, the results can serve as a reference for experiments. The results suggest that（i） it is reasonable to use zero-field CP,（ii） optimized ？T should be 2 K,（iii） it is better to keep △E 〈 EC, and（iv） E1〈 EC. Here, EC is the coercive field of material.

雷电间接效应多重脉冲组电流产生装置的设计

针对雷电间接效应多重脉冲组电流模拟需求,完成了雷电间接效应多重脉冲组模拟源的设计,采用20个Crowbar电路支路,通过分时放电的方式实现1个脉冲串内多脉冲输出需求,每个支路可以实现最小间隔30 ms的重复频率放电,从而实现3个脉冲串的输出需求。对放电支路的参数进行了详细设计,分析了电容、波尾电路电感、波尾电路电阻参数变化对输出特性的影响。分析了采用并联大电容实现放电电容重复频率快速充电的可行性,完成了装置的初步结构设计并结合装置结构简要分析了电路模拟参数设置的合理性。该装置建成后,可为电子、电气设备等开展测试提供技术支持。

碳排放权交易对试点地区绿色发展的影响及溢出效应——基于PSM-DID和SDID模型的实证分析

在碳中和、碳达峰背景下,本文选用2003~2021年全国273个地级市的面板数据,以碳排放权交易试点(CETP)为出发点,用生态效率测度绿色发展水平,通过PSM-DID和SDID模型实证检验了CETP对绿色发展的直接效应、间接效应和空间溢出效应。研究发现:(1)CETP能显著促进绿色发展,且通过了安慰剂检验和稳健性检验;(2)CETP产生的创新效应对绿色发展有推动作用,但产业结构效应不显著;(3)CETP对周边试点城市产生了显著负向的溢出效应,但对非试点城市的生态效率无明显影响。最后,结合以上研究结论,提出了政策建议。

飞机及分系统雷电效应标准及测试浅析

对国内外关军用及民用飞机平台、分系统及设备雷电标准进行分析,针对雷电直接效应和雷电间接效应的所有测试项目,详述每个测试项目的适用区域、波形要求、测试配置等。结合现有国内雷电设计验证标准及测试存在的不足,提出提升测试设备与试验验证技术匹配性、扩展军用标准测试领域、统一同军种同一平台要求等建议。通过对军用机载平台、设备及分系统关于雷电设计验证标准及测试的分析,为相关产品设计师及试验人员提供设计指标参考,明确产品关于雷电防护的设计要求及验证要求,做到有的放矢,提高设计费效比。

上海市洪涝灾害损失对长江下游地区的辐射影响

随着区域经济一体化程度的加深,跨区域产业关联损失已成为灾害损失评估不容忽视的一部分,准确量化洪涝灾害损失的辐射影响对于制定防灾减灾措施、减少洪涝灾害损失具有重要作用。在系统评估了不同暴雨重现期情景下上海市减停产损失的基础上,采用两区域投入产出模型,测算和分析了长江下游地区不同省(直辖市)的区域内乘数效应、区域间溢出效应和区域间反馈效应,量化了上海市洪涝灾害损失对长江下游地区的辐射影响。结果表明,暴雨重现期10 a、20 a、30 a、50 a、100 a时,上海市的减停产损失分别为14.01亿元、19.83亿元、25.58亿元、33.82亿元和46.24亿元;在长江下游地区,上海市与浙江省的经济相互影响强度最大,且跨区域产业关联损失以溢出效应为主导;上海市发生洪涝灾害时,跨区域波及效应将导致长江下游地区损失增加26.24%。因此,在城市之间联系日益紧密的情况下,不仅要关注洪涝灾害对自身的影响,同时也要采取有效措施减少地域之间的波及影响,以便更有效地开展防灾减灾工作。

绿色金融、碳交易与产业绩效:影响机理及中国7个试点的力证

目前,各界对绿色金融和碳交易影响产业绩效的认知和预期仍相对模糊或片面。基于实际发展进程与客观诉求,对C-D生产函数进行重构与改进,通过实证分析验证绿色金融和碳交易影响产业绩效的动态机制。结果表明:直接影响,绿色金融和碳交易的导入会短暂阻碍产业绩效的提升,但跨越“拐点”后可显著促进产业发展;间接影响,绿色金融和碳交易的推进均存在一个最佳时间段,不仅可通过生产要素影响产业绩效,而且可促进“劳动密集型”向“资本密集型+能源密集型”的结构升级;现阶段绿色金融和碳交易的相互影响不具有对称性。只有对“试点建设”成功经验和作用规律进行科学总结才可为“全国推广”奠定坚实基础。

Numerical study of aerosol effect on three types of clouds and precipitation in Beijing area

Three types of rainfall （storm, moderate and slight rainfall） in the Beijing area were simulated by the Weather Research and Fore- cast （WRF3.2） model coupled with Milbrandt-two-moment cloud microphysics scheme, to explore the effect of aerosols on clouds and precipitation under continental and maritime aerosol scenarios. Results indicate that an increase of aerosols has various effects on clouds and precipitation. （1） The amount of surface precipitation is obviously affected. With an increase of aerosol con- centration, the 48-hr total precipitation of storm and moderate rainfall decreased by 23% and 16.6%, respectively, and the 24-hr total precipitation of slight rainfall decreased by 14.0%. （2） The distribution of surface precipitation is also clearly affected. The average precipitation for a rain storm increases in most parts of western Beijing and decreases by more than 20 mm in most parts of eastern Beijing with increasing aerosol concentration. The average precipitation of moderate rainfall decreases by 0.1-5 mm in most parts of the Beijing area. The effect of increased aerosol concentration is weak for slight rainfall distribution in the study area. （3） With an increase of aerosol concentration, a narrower width and lower precipitation peak value are found in the storm rainfall, and its duration is prolonged for the high aerosol concentration. An earlier precipitation termination of moderate rainfall is found with increasing aerosol concentration. （4） The upper-air hydrometeors vary with aerosol concentration, For storm and moderate rainfall, significantly higher cloud water concentration and lower rain water were found under the continental aerosol scenario.

Model Analysis of the Anthropogenic Aerosol Effect on Clouds over East Asia

A coupled meteorology and aerosol/chemistry model WRF-Chem(Weather Research and Forecast model coupled with Chemistry) was used to conduct a pair of simulations with present-day(PD) and preindustrial(PI) emissions over East Asia to examine the aerosol indirect effect on clouds.As a result of an increase in aerosols in January,the cloud droplet number increased by 650 cm-3 over the ocean and East China,400 cm-3 over Central and Southwest China,and less than 200 cm-3 over North China.The cloud liquid water path(LWP) increased by 40-60 g m-2 over the ocean and Southeast China and 30 g m-2 over Central China;the LWP increased less than 5 g m-2 or decreased by 5 g m-2 over North China.The effective radius(Re) decreased by more than 4 μm over Southwest,Central,and Southeast China and 2μm over North China.In July,variations in cloud properties were more uniform;the cloud droplet number increased by approximately 250-400 cm-3,the LWP increased by approximately 30-50 g m-2,and Re decreased by approximately 3 ?m over most regions of China.In response to cloud property changes from PI to PD,shortwave(SW) cloud radiative forcing strengthened by 30 W m-2 over the ocean and 10 W m-2 over Southeast China,and it weakened slightly by approximately 2-10 W m-2 over Central and Southwest China in January.In July,SW cloud radiative forcing strengthened by 15 W m-2 over Southeast and North China and weakened by 10 W m-2 over Central China.The different responses of SW cloud radiative forcing in different regions was related to cloud feedbacks and natural variability.

A Simple Method of Measuring Vaccine Effects on Infectiousness and Contagion

The vaccination of one person may prevent another from becoming infected, either because the vaccine may prevent the first person from acquiring the infection and thereby reduce the probability of transmission to the second, or because, if the first person is infected, the vaccine may impair the ability of the infectious agent to initiate new infections. The former mechanism is referred as a contagion effect and the latter is referred as an infectiousness effect. By applying a principal stratification approach, the conditional infectiousness effect has been defined, but the contagion effect is not defined using this approach. Recently, new definitions of unconditional infectiousness and contagion effects were provided by applying a mediation analysis approach. In addition, a simple relationship between conditional and unconditional infectiousness effects was found under a number of assumptions. These two infectiousness effects can be assessed by very simple estimation and sensitivity analysis methods under the assumptions. Nevertheless, such simple methods to assess the contagion effect have not been discussed. In this paper, we review the methods of assessing infectiousness effects, and apply them to the inference of the contagion effect. The methods provided here are illustrated with hypothetical vaccine trial data.

充电基础设施对新能源汽车推广的影响研究

以2010—2020年中国37个城市为样本,研究充电基础设施对新能源汽车推广的影响。研究发现:充电基础设施的完善显著提高了中国新能源汽车的销量,以城市商业服务业设施用地面积作为公共充电桩的工具变量,以城市居民住宅竣工面积作为私人充电桩的工具变量,上述结论依然成立;在人口稠密、交通拥挤的大城市,与单纯增加充电桩数量相比,改进充电技术缩短充电时间更有助于刺激新能源汽车消费,特别是纯电动汽车;充电基础设施可用性的提高、可见度的增加和充电时间的缩短均能够显著增加新能源汽车的销量。