Sensitivity of the Grid-point Atmospheric Model of IAP LASG(GAMILI.I.0)Climate Simulations to Cloud Droplet Effective Radius and Liquid Water Path

This paper documents a study to examine the sensitivity to cloud droplet effective radius and liquid water path and the alleviation the energy imbalance at the top of the atmosphere and at the surface in the latest version of the Grid-point Atmospheric Model of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics （LASG）, Institute of Atmospheric Physics （IAP） （GAMIL1.1.0）. Considerable negative biases in all flux components, and thus an energy imbalance, are found in GAMIL1.1.0. In order to alleviate the energy imbalance, two modifications, namely an increase in cloud droplet effective radius and a decrease in cloud liquid water path, have been made to the cloud properties used in GAMIL. With the increased cloud droplet effective radius, the single scattering albedo of clouds is reduced, and thus the reflection of solar radiation into space by clouds is reduced and the net solar radiation flux at the top of the atmosphere is increased. With the reduced cloud optical depth, the net surface shortwave radiation flux is increased, causing a net warming over the land surface. This results in an increase in both sensible and latent heat fluxes over the land regions, which is largely balanced by the increased terrestrial radiation fluxes. Consequently, the energy balance at the top of atmosphere and at the surface is achieved with energy flux components consistent with available satellite observations.

A cloud model target damage effectiveness assessment algorithm based on spatio-temporal sequence finite multilayer fragments dispersion

To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage probability leveraging spatio-temporal finite multilayer fragments distribution and the target damage assessment algorithm based on cloud model theory.Drawing on the spatial dispersion characteristics of fragments of projectile proximity explosion,we divide into a finite number of fragments distribution planes based on the time series in space,set up a fragment layer dispersion model grounded in the time series and intersection criterion for determining the effective penetration of each layer of fragments into the target.Building on the precondition that the multilayer fragments of the time series effectively assail the target,we also establish the damage criterion of the perforation and penetration damage and deduce the damage probability calculation model.Taking the damage probability of the fragment layer in the spatio-temporal sequence to the target as the input state variable,we introduce cloud model theory to research the target damage assessment method.Combining the equivalent simulation experiment,the scientific and rational nature of the proposed method were validated through quantitative calculations and comparative analysis.

A cloud optical and microphysical property product for the advanced geosynchronous radiation imager onboard China's Fengyun-4 satellites: The first version

风云四号作为中国新一代静止气象卫星,提供了高时空分辨率的监测产品。本文介绍风云四号搭载的先进地球同步轨道辐射成像仪AGRI的云光学和微物理特性产品.该产品包含了基于双光谱通道反演的云光学厚度和云粒子有效半径产品,以及基于机器学习的云识别和云相态产品。与时空匹配的主动卫星观测结果对比显示,该产品的云识别和云相态的准确率分别在95%和85%;该产品提供的云光学厚度和云有效粒径与经典的MODIS产品的相关系数达到0.76和0.63.团队将持续优化和更新该云光学和微物理特性定量产品,服务风云四号卫星定量应用。

An Evaluation of the Effects of Cloud Parameterization in the R42L9 GCM

Cloud is one of the uncertainty factors influencing the performance of a general circulation model (GCM). Recently, the State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics (LASG/IAP) has developed a new version of a GCM (R42L9). In this work, roles of cloud parameterization in the R42L9 are evaluated through a comparison between two 20-year simulations using different cloud schemes. One scheme is that the cloud in the model is diagnosed from relative humidity and vertical velocity, and the other one is that diagnostic cloud is replaced by retrieved cloud amount from the International Satellite Cloud Climatology Project (ISCCP), combined with the amounts of high-, middle-, and low-cloud and heights of the cloud base and top from the NCEP. The boreal winter and summer seasonal means, as well as the annual mean, of the simulated top-of-atmosphere shortwave radiative flux, surface energy fluxes, and precipitation are analyzed in comparison with the observational estimates and NCEP reanalysis data. The results show that the scheme of diagnostic cloud parameterization greatly contributes to model biases of radiative budget and precipitation. When our derived cloud fractions are used to replace the diagnostic cloud amount, the top-of-atmosphere and surface radiation fields are better estimated as well as the spatial pattern of precipitation. The simulations of the regional precipitation, especially over the equatorial Indian Ocean in winter and the Asia-western Pacific region in summer, are obviously improved.

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.

Diffusion mechanism simulation of cloud manufacturing complex network based on cooperative game theory

Cloud manufacturing is a specific implementation form of the "Internet + manufacturing" strategy. Why and how to develop cloud manufacturing platform(CMP), however, remains the key concern of both platform operators and users. A microscopic model is proposed to investigate advantages and diffusion forces of CMP through exploration of its diffusion process and mechanism. Specifically, a three-stage basic evolution process of CMP is innovatively proposed. Then, based on this basic process, a more complex CMP evolution model has been established in virtue of complex network theory, with five diffusion forces identified. Thereafter, simulations on CMP diffusion have been conducted. The results indicate that, CMP possesses better resource utilization,user satisfaction, and enterprise utility. Results of simulation on impacts of different diffusion forces show that both the time required for CMP to reach an equilibrium state and the final network size are affected simultaneously by the five diffusion forces. All these analyses indicate that CMP could create an open online cooperation environment and turns out to be an effective implementation of the "Internet + manufacturing" strategy.

Observational Diagnosis of Cloud Phase in the Winter Antarctic Atmosphere for Parameterizations in Climate Models

The cloud phase composition of cold clouds in the Antarctic atmosphere is explored using data from the Moderate Resolution Imaging Spectroradiometer （MODIS） and Cloud-Aerosol Lidar with Orthogonal Polarization （CALIOP） instruments for the period 2000-2006. We used the averaged fraction of liquid-phase clouds out of the total cloud amount at the cloud tops since the value is comparable in the two measurements. MODIS data for the winter months （June, July, and August） reveal liquid cloud fraction out of the total cloud amount significantly decreases with decreasing cloud-top temperature below 0°C. In addition, the CALIOP vertical profiles show that below the ice clouds, low-lying liquid clouds are distributed over ～20% of the area. With increasing latitude, the liquid cloud fraction decreases as a function of the local temperature. The MODIS-observed relation between the cloud-top liquid fraction and cloud-top temperature is then applied to evaluate the cloud phase parameterization in climate models, in which condensed cloud water is repartitioned between liquid water and ice on the basis of the grid point temperature. It is found that models assuming overly high cut-offs （ -40°C） for the separation of ice clouds from mixed-phase clouds may significantly underestimate the liquid cloud fraction in the winter Antarctic atmosphere. Correction of the bias in the liquid cloud fraction would serve to reduce the large uncertainty in cloud radiative effects.

VARIATIONS OF CLOUD FRACTION OVER EAST ASIA UNDER GLOBAL WARMING CONDITIONS IN THE PAST 20 YEARS

Based on the variation of cloud fraction revealed by D2 Cloud Climatic Data of the InternationalSatellite Cloud Climatology Project and trend analysis methods, the trend of different types of cloud fractionover East Asia during 1984-2006 is obtained. The analysis focuses on the relationship between temperatureand different cloud fraction under the background of globe warming. The result shows a fluctuatingdecreasing tendency in the total cloud fraction, high-level cloud and low-level cloud over East Asia with thedecrement being 2.24%, 1.65% and 1.68%, respectively, while the mid-level cloud increases by 1.07%. Inaddition, there are great regional differences in cloud fraction. Temperature and water-vapor contentvariation caused by the greenhouse effects over East Asia is the primary reason for the variation of cloudfraction. Over the Tibetan Plateau, the Bay of Bengal and the Intertropical Convergence Zone, thetemperature is negatively correlated with high-level cloud, but positively correlated with mid- and low-levelcloud. However, over the West Pacific and the ocean east and north of Japan, the temperature is negativelycorrelated with low-level cloud but positively correlated with high-level cloud.

Data-driven Estimation of Cloud Effects on Surface Irradiance at Xianghe,a Suburban Site on the North China Plain

Clouds are a dominant modulator of the energy budget.The cloud shortwave radiative effect at the surface(CRE)is closely related to the cloud macro-and micro-physical properties.Systematic observation of surface irradiance and cloud properties are needed to narrow uncertainties in CRE.In this study,1-min irradiance and Total Sky Imager measurements from 2005 to 2009 at Xianghe in North China Plain are used to estimate cloud types,evaluate cloud fraction(CF),and quantify the sensitivities of surface irradiance with respect to changes in CF whether clouds obscure the sun or not.The annual mean CF is 0.50,further noting that CF exhibits a distinct seasonal variation,with a minimum in winter(0.37)and maximum in summer(0.68).Cumulus occurs more frequently in summer(32%),which is close to the sum of the occurrence of stratus and cirrus.The annual CRE is–54.4 W m^(–2),with seasonal values ranging from^(–2)9.5 W m^(–2)in winter and–78.2 W m^(–2)in summer.When clouds do not obscure the sun,CF is a dominant factor affecting diffuse irradiance,which in turn affects global irradiance.There is a positive linear relationship between CF and CRE under sun-unobscured conditions,the mean sensitivity of CRE for each CF 0.1 increase is about 1.2 W m^(–2)[79.5°<SZA(Solar Zenith Angle)<80.5°]to 7.0 W m^(–2)(29.5°<SZA<30.5°).When clouds obscure the sun,CF affects both direct and diffuse irradiance,resulting in a non-linear relationship between CF and CRE,and the slope decreases with increasing CF.It should be noted that,although only data at Xianghe is used in this study,our results are representative of neighboring areas,including most parts of the North China Plain.

An Evidence of Aerosol Indirect Effect on Stratus Clouds from the Integrated Ground-Based Measurements at the ARM Shouxian Site

The aerosol effect on clouds was explored using remote sensing of aerosol and cloud data at Shouxian, China. Non-precipitation, ice-free, and overcast clouds were firstly chosen by a combination of sky im- ages from the Total Sky Imager （TSI）, cloud base heights from the Ceilometer, and vertical temperature profiles from the Balloon-Borne Sounding System （BBSS）. Six cases were chosen in summer, and seven in autumn. The averaged cloud effective radii （re）, cloud optical depth （COD）, aerosol total light scattering coefficient （a）, and liquid water path （LWP） are, respectivey, 6.47 μm, 35.4, 595.9 mm-1, 0.19 mm in summer, and 6.07 μm, 96.0, 471.7 mm-1, 0.37 mm in autumn. The correlation coefficient between re and tc was found to change from negative to positive value as LWP increases.

Variation of sulfate aerosol concentrations over the western Pacific and their effect on clouds, radiation and precipitation

Under bilateral cooperation between the United States of America and the People's Republic of China, a series of research cruises were conducted over the western Pacific Ocean. It was found that a) the non-sea-salt sulfate aerosol particles are the major source of cloud condensation nuclei, b) the population of clouds and the total albedo are proportional to the concentration of condensation nuclei and consequently to the concentration of the non-sea-salt aerosol particles, and c) the amount of rainfall is inversely proportional to the concentration of non-sea-salt sulfate aerosol particles. It seems that anthropogenic sulfate aerosol particles affect the regional planetary albedo and climate and that the contribution from biogenically derived sulfate aerosol particles is of lesser importance.

A Comprehensive Observational Analysis for the Effects of Gas Cannons on Clouds and Precipitation

To analyze the effects of gas cannons on clouds and precipitation,multisource observational data,including those from National Centers for Environmental Prediction(NCEP)reanalysis,Hangzhou and Huzhou new-generation weather radars,laser disdrometer,ground-based automatic weather station,wind profiler radar,and Lin'an C-band dualpolarization radar,were adopted in this study.Based on the variational dual-Doppler wind retrieval method and the polarimetric variables obtained by the dual-polarization radar,we analyzed the microphysical processes and the variations in the macro-and microphysical quantities in clouds from the perspective of the synoptic background before precipitation enhancement,the polarization echo characteristics before,during and after enhancement,and the evolution of the fine three-dimensional kinematic structure and the microphysical structure.The results show that the precipitation enhancement operation promoted the development of radar echoes and prolonged their duration,and both the horizontal and vertical wind speeds increased.The dual-polarization radar echo showed that the diameter of the precipitation particles increased,and the concentration of raindrops increased after precipitation enhancement.The raindrops were lifted to a height corresponding to 0 to-20℃due to vertical updrafts.Based on the disdrometer data during precipitation enhancement,the concentration of small raindrops(lgN_(w))showed a significant increase,and the mass-weighted diameter D_(m)value decreased,indicating that the precipitation enhancement operation played a certain“lubricating”effect.After the precipitation enhancement,the concentration of raindrops did not change much compared with that during the enhancement process,while the Dm increased,corresponding to an increase in rain intensity.The results suggest the positive effect of gas cannons on precipitation enhancement.

The Role of Clouds in Global Radiation Changes Measured in Israel during the Last Sixty Years

An analysis of global radiation measurements and fractional cloud cover observations made in the Israel Meteorological Service’s network of climate stations demonstrated a significant decrease in the transmittance of solar radiation through the atmosphere during the last 60 years. The major cause was the reduced transparency of clouds. Under completely overcast skies with complete cloud cover transmission in the industrialized central coastal region decreased from 0.41 in the mid-20th century to 0.21 in the first decade of the 21st century. Under cloudless skies the reduction in the transmission of global radiation was less, from 0.79 to 0.71, and not statistically significant. Similar but somewhat smaller changes were observed in the less industrialized central hill region. Multi-linear analysis showed that since 1970, 61% of the measured decline in global radiation was attributable to changes in fractional cloud cover but only 2% to the marked increase in local fuel combustion;there was no statistically significant interaction between the two parameters.

An evaluation of the Arctic clouds and surface radiative fluxes in CMIP6 models

To assess the performances of state-of-the-art global climate models on simulating the Arctic clouds and surface radiation balance,the 2001–2014 Arctic Basin surface radiation budget,clouds,and the cloud radiative effects(CREs)in 22 coupled model intercomparison project 6(CMIP6)models are evaluated against satellite observations.For the results from CMIP6 multi-model mean,cloud fraction(CF)peaks in autumn and is lowest in winter and spring,consistent with that from three satellite observation products(Cloud Sat-CALIPSO,CERESMODIS,and APP-x).Simulated CF also shows consistent spatial patterns with those in observations.However,almost all models overestimate the CF amount throughout the year when compared to CERES-MODIS and APP-x.On average,clouds warm the surface of the Arctic Basin mainly via the longwave(LW)radiation cloud warming effect in winter.Simulated surface energy loss of LW is less than that in CERES-EBAF observation,while the net surface shortwave(SW)flux is underestimated.The biases may result from the stronger cloud LW warming effect and SW cooling effect from the overestimated CF by the models.These two biases compensate each other,yielding similar net surface radiation flux between model output(3.0 W/m2)and CERES-EBAF observation(6.1 W/m2).During 2001–2014,significant increasing trend of spring CF is found in the multi-model mean,consistent with previous studies based on surface and satellite observations.Although most of the 22 CMIP6 models show common seasonal cycles of CF and liquid water path/ice water path(LWP/IWP),large inter-model spreads exist in the amounts of CF and LWP/IWP throughout the year,indicating the influences of different cloud parameterization schemes used in different models.Cloud Feedback Model Intercomparison Project(CFMIP)observation simulator package(COSP)is a great tool to accurately assess the performance of climate models on simulating clouds.More intuitive and credible evaluation results can be obtained based on the COSP model output.In the future,with the release of more COSP output of CMIP6 models,it is expected that those inter-model spreads and the model-observation biases can be substantially reduced.Longer term active satellite observations are also necessary to evaluate models’cloud simulations and to further explore the role of clouds in the rapid Arctic climate changes.

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 （P1） 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 in- creased less than 5 g m-2 or decreased by 5 g m2 over North China. The effective radius （Re） decreased by more than 4 pm over Southwest, Central, and Southeast China and 2 pm over North China. In July, variations in cloud properties were more uniform; the cloud droplet number increased by approximately 250400 cm-3, the LWP increased by approximately 30-50 g m 2, and Re decreased by approximately 3 μm over most regions of China. In response to cloud property changes from PI to PD, shortwave （SW） cloud radiative m-2 over the ocean and 10 forcing strengthened by 30 W 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 l0 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.

In the Future, Learning in the Cloud Will be More Effective than Learning in A Physical University

With the progress of technology,learning in the cloud has becoming the new teaching and learning model in education.Compared with the traditional class,it influences on improving academic performance,stimulating learning motivation and saving time.However,most changeling of it is increased of dropout.What is more,the feeling of lacking interpersonal communication happened between the teachers and students.

Absence of the Impact of the Flux of Cosmic Rays and the Cloud Cover on the Energy Balance of the Earth

The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area of the cloud cover.Svensmark et al.suggest that the increase in the area of the cloud cover in the lower atmosphere,presumably caused by an increase in the flux of galactic cosmic rays during the quasi-bicentennial minimum of solar activity,results only in an increase in the fraction of the solar radiation reflected back to the space and weakens the flux of the solar radiation that reached the Earth surface.It is suggested,without any corresponding calculations of the variations of the average annual energy balance of the EarthЕ,that the consequences will include only a deficit of the solar energy absorbed by the Earth and a cooling of the climate up to the onset of the Little Ice Age.These suggestions ignore simultaneous impact of the opposite aspects of the increase in the area of the cloud cover on the climate warming.The latter will result from a decrease in the power of thermal radiation of the Earth’s surface released to the space,and also in the power of the solar radiation reflected from the Earth’s surface,due to the increase in their absorption and reflection back to the surface.A substantial strengthening in the greenhouse effect and the narrowing of the atmospheric transparency window will also occur.Here,we estimate the impact of all aspects of possible long-term 2%growth of the cloud cover area in the lower atmosphere byЕ.We found that an increase in the cloud cover area in the lower atmosphere will result simultaneously both in the decrease and in the increase in the temperature,which will virtually compensate each other,while the energy balance of the Earth E before and after the increase in the cloud cover area by 2%will stay essentially the same:E1-E0≈0.

Water Vapor and Cloud Radiative Forcings over the Pacific Ocean Simulated by the LASG/IAP AGCM:Sensitivity to Convection Schemes

Characteristics of the total clear-sky greenhouse effect （GA） and cloud radiative forcings （CRFs）, along with the radiative-related water vapor and cloud properties simulated by the Spectral Atmospheric Model developed by LASGIAP （SAMIL） are evaluated. Impacts of the convection scheme on the simulation of CRFs are discussed by using two AMIP （Atmospheric Model Inter-comparison Project） type simulations employing different convection schemes： the new Zhang-McFarlane （NZH） and Tiedtke （TDK） convection schemes. It shows that both the climatological GA and its response to El Nio warming are simulated well, both in terms of spatial pattern and magnitude. The impact of the convection scheme on GA is not significant. The climatological longwave CRF （LWCRF） and its response to El Nio warming are simulated well, but with a prominently weaker magnitude. The simulation of the climatology （response） of LWCRF in the NZH （TDK） run is slightly more realistic than in the TDK （NZH） simulation, indicating significant impacts of the convection scheme. The shortwave CRF （SWCRF） shows large biases in both spatial pattern and magnitude, and the results from the TDK run are better than those from the NZH run. A spuriously excessive negative climatological SWCRF over the southeastern Pacific and an insufficient response of SWCRF to El Nio warming over the tropical Pacific are seen in the NZH run. These two biases are alleviated in the TDK run, since it produces vigorous convection, which is related to the low threshold for convection to take place. Also, impacts of the convection scheme on the cloud profile are discussed.

Characteristics of the Heat Island Effect in Shanghai and Its Possible Mechanism

The characteristics of the urban heat island effect and the climate change in Shanghai and its possible mechanism are analyzed based on monthly meteorological data from 1961 to 1997 at 16 stations in Shanghai and its adjacent areas. The results indicate that Shanghai City has the characteristics of a heat island of air temperature and maximum and minimum air temperature, a cold island of surface soil temperature, a weak rainy island of precipitation, and a turbid island of minimum visibility and aerosols, with centers at or near Longhua station (the urban station of Shanghai). Besides theses, the characteristics of a cloudy island and sunshine duration island are also obvious, but their centers are located in the southern part of the urban area and in the southern suburbs. A linear trend analysis suggests that all of the above urban effects intensified from 1961 to 1997. So far as the heat island effect is concerned, the heat island index (difference of annual temperature between Longhua and Songjiang stations) strengthens (weakens) as the economic development increases (decreases). The authors suggest that the heating increase caused by increasing energy consumption due to economic development is a main factor in controlling the climate change of Shanghai besides natural factors. On the other hand, increasing pollution aerosols contribute to the enhancement of the turbid island and cooling. On the whole, the heating effect caused by increasing energy consumption is stronger than the cooling effect caused by the turbid island and pollution aerosols.

Analysis of the stress wave and rarefaction wave produced by hypervelocity impact of sphere onto thin plate

Shock wave is emitted into the plate and sphere when a sphere hypervelocity impacts onto a thin plate.The fragmentation and phase change of the material caused by the propagation and unloading of shock wave could result in the formation of debris cloud eventually.Propagation models are deduced based on one-dimensional shock wave theory and the geometry of sphere,which uses elliptic equations(corresponding to ellipsoid equations in physical space)to describe the propagation of shock wave and the rarefaction wave.The“Effective thickness”is defined as the critical plate thickness that ensures the rarefaction wave overtake the shock wave at the back of the sphere.The“Effective thickness”is directly related to the form of the debris cloud.The relation of the“Effective thickness”and the“Optimum thickness”is also discussed.The impacts of Al spheres onto Al plates are simulated within SPH to verify the propagation models and associated theories.The results show that the wave fronts predicted by the propagation models are closer to the simulation result at higher impact velocity.The curvatures of the wave fronts decrease with the increase of impact velocities.The predicted“Effective thickness”is consistent with the simulation results.The analysis about the shock wave propagation and unloading in this paper can provide a new sight and inspiration for the quantitative study of hypervelocity impact and space debris protection.