Cloudiness regime shift during 1946—1992 recorded by coral in the South China Sea

By extracting and comparing long-term trend components of coral gray value, sea surface temperature, cloudiness, and net heat flux for the period of 1946-1992, the relationships among them are addressed. There exists a prominent regime shift in the cloudiness associated with the corresponding variabilities of sea surface temperature and net heat flux occurred in the mid-1960s, which can be successfully recorded by coral gray value, a climatic proxy. Long-term cloudiness variations in the South China Sea are completely opposite to the equatorial western Pacific in the past five decades, whereas they share a similar trend to that over Asian monsoon prevailing waters. The fact that the coral gray value is highly correlated to cloudiness provides a unique perspective on utilizing this coral to study cloudiness variations in the pre-instrumental period.

Overcast sky condition prevails on and influences the biometeorology of the tropical Andean Páramos

Clouds play a major role in modulating the biometeorological processes. We studied the influence of cloudiness on four biometeorological variables:daily air temperature(Tair), relative humidity(RH),reference evapotranspiration(ETr),and photosynthetic active radiation(PAR), recorded at four sites of Andean Páramos in southern Ecuador during 2.5 to 5.5 years. First, we quantified both the cloud cover percentage(Cloud%) creating cloud masks over the visible bands of Landsat 7 images and the sky condition(K_(T)) using the records of solar and extraterrestrial radiation. Second, we estimated KTfrom Cloud%. Finally, we quantified T_(air), RH, ET_(r), and PAR under clear, cloudy, and overcast K_(T) and their dependence on KT. The average Cloud% ranged between 65%–76%, and KTcorroborated the prevailing overcast sky(between 55% and 72.5% of the days) over the páramos. The proposed model performed well in the sites of calibration(R^(2)= 0.80;MBE = 0.00;RMSE = 0.05) and validation(R^(2)= 0.74;MBE =-0.07;RMSE = 0.11). The overcast sky diminished T_(air)(≤ 10℃), ET_(r)(≤ 1.6 mm day-1), and PAR(4 MJ m^(-2)day^(-1)) and increased RH(≥ 88%),while the variables showed the opposite behavior during the uncommon clear sky(≤ 5.5% of the days).Thus, mostly the dynamic of RH(R^(2)≥ 0.62), ETr(R^(2)≥ 0.85), and PAR(R2≥ 0.77) depended on K_(T). Hence,the prevailing overcast sky influenced the biometeorology of the páramos.

A cloud Bayesian network approach to situation assessment of scouting underwater targets with fixed-wing patrol aircraft

The battlefield situation changes rapidly because underwater targets'are concealment and the sea environment is uncertain.So,a great number of situation information greatly increase,which need to be dealt with in the course of scouting underwater targets.Situation assessment in sea battlefield with a lot of uncertain information is studied,and a new situation assessment method of scouting underwater targets with fixed-wing patrol aircraft is proposed based on the cloud Bayesian network,which overcomes the deficiency of the single cloud model in reasoning ability and the defect of Bayesian network in knowledge representation.Moreover,in the method,the cloud model knowledge deal with the input data of Bayesian network reasoning,and the advantages in knowledge representation of cloud theory and reasoning of Bayesian network are applied;also,the fuzziness and stochasticity of cloud theory in knowledge expression,the reasoning ability of Bayesian network,are combined.Then,the situation assessment model of scouting underwater targets with fixed-wing patrol aircraft is established.Hence,the directed acyclic graph of Bayesian network structure is constructed and the assessment index is determined.Next,the cloud model is used to deal with Bayesian network,and the discrete Bayesian network is obtained.Moreover,after CPT of each node and the transformation between certainty degree and probability are accomplished;the final situation level is obtained through a probability synthesis formula.Therefore,the target type and the operational intention of the other side are deduced to form the battlefield situation.Finally,simulations are carried out,and the rationality and validity of the proposed method are testified by simulation results.By this method,the battlefield situation can be gained.And this method has a wider application range,especially for large sample data processing,and it has better practicability.

Site testing campaign for the Large Optical Telescope at the Ali site

The Large Optical/infrared Telescope(LOT)is a ground-based 12 m diameter telescope which is proposed to be built in western China.The site selection for LOT in China began in 2016,and Ali was listed as one of the three candidate sites.Remote studies and local surveys have been carried out for more than 15 years in western China,and the results show that Ali is a promising site with comprehensive quality in terms of atmospheric and supporting conditions.An overview of the site testing campaign at the Ali site from 2016 to 2019 is presented.After the two years of data collection,the overall median seeing value is found to be 1.17 arcsec,the observable nights are 81.71%and the good observable nights are 71.76%.The weather conditions as follows,the median night temperature value is-5.18℃,the median night relative humidity value is 41.25%,the median night atmospheric pressure value is 540.92 hPa,the median night wind speed value is 7.41 m s-1 and the mainly wind direction is southwestern(SW).The median night sky background value is 22.07 magV.We also discuss the wind speed at different locations on-site,the possibility of light pollution and the effect of wind speed on differential image motion monitor(DIMM)seeing measurements.

Amplitude—Phase Characteristics of the Annual Cycle of Surface Air Temperature in the Northern Hemisphere

The amplitude-phase characteristics (APC) of surface air temperature (SAT) annual cycle (AC) in the Northern Hemisphere are analyzed. From meteorological observations for the 20th century and meteorological reanalyses for its second half, it is found that over land negative correlation of SAT AC amplitude with annual mean SAT dominates. Nevertheless, some exceptions exist. The positive correlation between these two variables is found over the two desert regions: in northern Africa and in Central America. Areas of positive correlations are also found for the northern Pacific and for the tropical Indian and Pacific Oceans. Southward of the characteristic annual mean snow-ice boundary (SIB) position, the shape of the SAT AC becomes more sinusoidal under climate warming. In contrast, northward of it, this shape becomes less sinusoidal. The latter is also found for the above-mentioned two desert regions. In the Far East (southward of about 50?N), the SAT AC shifts as a whole: here its spring and autumn phases occur earlier if the annual mean SAT increases. From energy-balance climate considerations, those trends for SAT AC APC in the middle and high latitudes are associated with the influence of the albedo-SAT feedback due to the SIB movement. In the Far East the trends are attributed to the interannual cloudiness variability, and in the desert regions, to the influence of a further desertification and/or scattering aerosol loading into the atmosphere. In the north Pacific, the exhibited trends could only be explained as a result of the influence of the greenhouse-gases loading on atmospheric opacity. The trends for SAT AC APC related to the SIB movement are simulated reasonably well by the climate model of intermediate complexity (IAP RAS CM) in the experiment with greenhouse gases atmospheric loading. In contrast, the tendencies resulting from the cloudiness variability are not reproduced by this model. The model also partly simulates the tendencies related to the desertification processes.

开源PaaS平台初探

文章在研究Cloud Foundry、Cloudify、Docker开源PaaS平台的架构特征及其实现模式与策略的基础上,总结了当前开源PaaS平台的技术发展趋势,提出了电信运营商业务网络演进的发展策略。

皮克斯动画短片创意分析——以《Partly Cloudy》为例

皮克斯动画工作室(Pixar Animation Studios)简称皮克斯,这个总部坐落于美国加利福尼亚州爱莫利维尔市的动画制作公司于1986年成立,一直致力于制作优秀的三维电脑动画作品。

Ozone and Aerosol Influence on Ultraviolet Radiation on the East Coast of the Brazilian Northeast

The purpose of this research is to determine the influence of Total Ozone and Aerosols about variability of Ultraviolet Radiation (UV) in the east coast of the Northeastern region of Brazil through measures from multispectral sensor GUV (Ground-based Ultraviolet Radiometer). The methodology consisted of descriptive study and cluster analyses using data of UV in channels UVB (305 nm) and UVA (320 nm, 340 nm and 380 nm) and data of UV index, Total Ozone, Aerosol, Global Solar Radiation, Cloudiness and Wind. The results for city of Natal indicated that an annual event occurs in September/October which stabilizes the UV or UV Index when Total Ozone levels reach their annual maximum. This event is influenced by marine Aerosol that is found on mainland at a higher concentration in September due to greater Wind intensity and their southeasterly direction (sea for land). The cluster analysis using the variables above allowed us to detect three different groups: the first group is formed by Natal, Recife and Jo?o Pessoa and so determined that this event occurs in these three cities;the second group is formed by Maceió, Aracaju and Salvador and the third group includes only Fortaleza and had different results.

Ultraviolet Radiation in Overcast Sky at the Surface

Based on the analysis of one year of observation data of solar radiation at the ground in Beijing in 1990, a simple empirical formula for calculating UV radiation in overcast sky is established. The formula is Quv/Quv0 = A1S + A0, where Quv and Quvo are monthly mean daily sums of UV exposure in overcast sky and clear sky, respectively. 5 is the daily sunshine hours. The calculated results agree well with the observed. The maximum and minimum relative biases are 9.9% and 0.1%, respectively, and the yearly relative bias is 2.9%. The ratio of ultraviolet radiation of overcast sky to clear sky in 1990 is between 44.6% and 61.8%, and the yearly average is 53.9%. Thus, almost half of the UV energy is lost in the atmosphere in overcast sky in 1990.

Characterization of Spatio-Temporal Variability of Irradiation, Nebulosity and Aerosols Optical Depth in 10˚North-20˚North African Band

This work concerns the 10? North, 20? North African band. Area renowned for having some of the poorest countries in the world. It is also home to the Sahelian strip and part of the Sahara. The countries in this zone have a relatively low electrification rate compared to the enlightened country. To solve this problem, these countries want to turn to renewable energies such as photovoltaics (renewable energy obtained through solar radiation). Therefore, understanding the behavior of irradiation and cloudiness in the 10 - 20 band becomes necessary. The application of the empirical orthogonal functions to the different cloud layers and to the irradiation reveals a seasonality of the latter, in particular compared to the first modes of the empirical orthogonal functions (EOF1). Indeed, by filtering in time and space to isolate solar radiation and cloudiness, the EOF1 expresses respectively 94.3% of the variation of descending solar radiation in clear sky in the 10 - 20 band. Note 65.7% for global radiation, 54.4% for cloudiness at 450 hPa, 69.6% for cloudiness between 800 hPa and 450 hPa, 76.6% for low cloudiness, 61.4% for total cloudiness. These results allow us to say that we have generally good sunshine over several months, with little cloud cover in this band. However, since this zone is considered to be part of the main aerosol emission source zones, it is important in their temporal consideration of the optical depth. By doing the wavelet analysis on the optical depth data from Dakar and Banizoumbou, we note that the average dust presence spectrum over the entire period from 1997 to 2019 in the two stations with a slight shift compared to the peaks and the maximum observed value. A sign that there is a strong presence of dust in this area and that it should be taken into account for any photovoltaic installation in this area.

上层大气中石质流星尾迹的紫外光谱模拟

利用Sparrow的粒子碰撞理论,计算了海拔100～90 km范围内的大气中的不同初始地心坐标速度的石质流星的有效温度;分别采取不同的成分配比,给出了速度72 km·s-1的石质流星尾迹主要成分的粒子数密度;应用大型光谱合成程序Cloudy模拟了上述流星尾迹的240～400 nm波段紫外辐射,给出了若干预期的强谱线的相对强度;经比较发现,有效温度5 680 K、蒸汽分压0.1 Pa的尾迹光谱比较接近观测结果.

Trends in sunshine duration and atmospheric visibility in the Yunnan-Guizhou Plateau,1961-2005

Using the observed data from 184 stations over the Yunnan-Guizhou Plateau （YGP） from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility （Vd）, dry extinction, and water vapor over the YGP are analyzed. The results show that 85% of the stations recorded shortening annual sunshine duration, with the decrease rates between -12.2 and -173.7 h/10yr. Results of Mann-Kendall tests indicate that, among the stations with decreasing sunshine duration, 63.7% of them experienced an abrupt change that started in the 1970s and peaked in the 1980s. This decreasing trend has reversed in the early years of the 21st century. The cloud cover and water vapor content in the mid and lower levels over the YGP had no obvious changes during the study period. The annual averages of Vd declined from 34 km in the 1960s to 27 km at present. The annual mean dry extinction coefficient trended upward, from 0.176 to 0.190, on the YGP from 1980 to 2005. Analyses of cloud cover, water vapor, atmospheric visibility, and dry extinction coefficient revealed that emitted tropospheric aerosols （including air pollutants） resulting from increased energy consumption over the YGP could be a major Factor influencing the reductions of sunshine duration and atmospheric visibility.

Preliminary Study on Direct Assimilation of Cloud-affected Satellite Microwave Brightness Temperatures

Direct assimilation of cloud-affected microwave brightness temperatures from AMSU-A into the GSI three-dimensional variational （3D-Var） assimilation system is preliminarily studied in this paper. A combination of cloud microphysics param- eters retrieved by the 1D-Var algorithm （including vertical profiles of cloud liquid water content, ice water content, and rain water content） and atmospheric state parameters from objective analysis fields of an NWP model are used as background fields. Three cloud microphysics parameters （cloud liquid water content, ice water content, and rain water content） are ap- plied to the control variable. Typhoon Halong （2014） is selected as an example. The results show that direct assimilation of cloud-affected AMSU-A observations can effectively adjust the structure of large-scale temperature, humidity and wind anal- ysis fields due to the assimilation of more AMSU-A observations in typhoon cloudy areas, especially typhoon spiral cloud belts. These adjustments, with temperatures increasing and humidities decreasing in the movement direction of the typhoon, bring the forecasted typhoon moving direction closer to its real path. The assimilation of cloud-affected satellite microwave brightness temperatures can provide better analysis fields that are more similar to the actual situation. Furthermore, typhoon prediction accuracy is improved using these assimilation analysis fields as the initial forecast fields in NWP models.

Infrared Radiance Simulation and Application under Cloudy Sky Conditions Based on HIRTM

An algorithm based on hyperspectral infrared cloudy radiative transfer model (HIRTM) is introduced and a simulation method for infrared image of the generation geostationary meteorological satellite is proposed. Based on the parameters from weather research and forecast (WRF), such as the water content, atmospheric temperature, and humidity profile, the simulation data for the advanced Himawari imager (AHI) infrared radiative (IR) channels of Himawari-8 are obtained. Simulated results based on HIRTM agree well with the observed data. Further, the movement, development, and change of the cloud are well predicated. And the simulation of IR cloud image for the weather forecast has been obtained. This paper provides an improved method for evaluation and improvement of regional numerical model for weather forecast.

Comparative studies in method for stratigraphical structure measurement of ice cores: Identification of cloudy bands

Cloudy bands are typical stratigraphic structure in deep ice core. Detailed recording of cloudy bands is important for dating of ice core since pair of series cloudy band and clear layer is corresponds to annual layer and it sometimes corresponds to volcanic ash layer. We developed two type scanners, transmitted light method and laser tomograph method for the stratigraphic study. Measurements were carried out for NGRIP deep ice core, which containing many cloudy bands, using the two type scanners and digital camera. We discussed about the possibility of identification of cloudy bands by each method and about advantage and disadvantage of measurements and their results.

A Page from a Student’s Diary

April 24, 2018 Tuesday Cloudy This morning, I went to school early. When I got to the school gate, I saw a boy fall off his bike and lie on the ground. He was badly hurt and couldn’t move.

EPQ model with the effect of inflation and reliability for partial trade credit under fuzzy and cloudy fuzzy environment

The proposed study offers the first-of-its-kind economic production quantity model for deteriorating items having a demand rate to be price dependent under the effect of inflation and reliability with partial trade credit.The model is extended under an uncertain environment by assuming inventory parameters to be triangular fuzzy numbers and cloudy triangular fuzzy numbers.The objective of the study is to maximize the profit of the inventory system and to identify the most suitable environment for the proposed problem.Results are verified using the numerical study.Furthermore,the comparative study is presented to justify the nature of fuzzy and cloudy fuzzy environments.Sensitivity analysis under all environments is conducted to identify the most sensitive parameters of all.

On the Assimilation of Satellite Sounder Data in Cloudy Skies in Numerical Weather Prediction Models

Satellite measurements are an important source of global observations in support of numerical weather prediction（NWP）.The assimilation of satellite radiances under clear skies has greatly improved NWP forecast scores.However,the application of radiances in cloudy skies remains a significant challenge.In order to better assimilate radiances in cloudy skies,it is very important to detect any clear field-of-view（FOV） accurately and assimilate cloudy radiances appropriately.Research progress on both clear FOV detection methodologies and cloudy radiance assimilation techniques are reviewed in this paper.Overview on approaches being implemented in the operational centers and studied by the satellite data assimilation research community is presented.Challenges and future directions for satellite sounder radiance assimilation in cloudy skies in NWP models are also discussed.

Important mesoscale phenomena in gas phase fluidized bed ethylene polymerization

Gas phase fluidized bed processes have been widely applied to polyethylene production.In these processes,the flow,mass transfer,and reaction rate on the microscale and macroscale are strongly coupled because of the multiphase and multiscale nature of the fluidization system.Understanding mesoscale phenomena is therefore essential to the quantitative translation of the knowledge obtained from the microscale to the macroscale.This paper reviews the development of ethylene polymerization gas phase processes while focussing on studies regarding mesoscale phenomena.These include experimental characterizations,mathematical modelling and control strategies.Trends and future developments in this field are also discussed.

Challenges in uncovering the origin of the proton’s spin

One of the most fascinating challenges facing modern strong interaction physics is to understand the origin of the spin of the nucleon in terms of the spin and orbital angular momentum of the quarks and gluons.We review recent progress on this problem as well as some of the uncertainties associated with state of the art lattice QCD simulations.In particular,we explain the importance of the corrections associated with chiral extrapolation and finite volume corrections,especially for the term B（0） extracted from the appropriate low moment of the deeply virtual Compton scattering amplitude.