Table of Content

20 July 2015, Volume 51 Issue 4

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Articles

Chinese Syntactic Parsing with Word Sense Disambiguation

LI Dongchen;ZHANG Xiantao;FAN Yang;WU Xihong

2015, 51(4):  577-584.  DOI: 10.13209/j.0479-8023.2015.054

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This paper proposes an integrated parsing and word sense disambiguation system. The ambiguity problem is solved when introducing semantic knowledge into the parser by modifying the lexical grammar iteratively. Syntactic information is used to deal with polysemous words in the training process. The experimental results show that the new method not only improves the parsing performance, but also has a good performance on word sense disambiguation.option and the closed fuel cycle (CFC) option which consists of the thermal reactor recycle (TRR) and the fast reactor along with thermal reactor recycle (FRR) are calculated. The natural uranium demand, the separate work demand, the nuclear power demand on alternative style of reactors, the nuclear assemblies demand and the disposal demand of nuclear wastes are obtained. According to these results, the FRR option is the optimal strategy with the highest utility of uranium as well as the minimum accumulation of the nuclear wastes.

Influence of Air on the Performance of InAs Nanowire FET

ZHANG Xintong;LI Xing;WANG Xiaoye;FU Mengqi;YANG Tao;CHEN Qing

2015, 51(4):  585-590.  DOI: 10.13209/j.0479-8023.2015.013

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Planar field effect transistor nanodevices were fabricated based on individual InAs nanowires. The electrical performance of the devices was measured and studied in vacuum, air, N2, O2, H2O and pollutant in air, NO2. Compared with the performance in vacuum, the performance of the device in air changes, e.g. the threshold voltage of the device (VT) shifts to positive direction, the off-state current (Ioff) increases and the on-off ratio (Ion/Ioff) decreases in air. The main air component, N2, does not have distinguishable impact on the performance of the device. The effect of O2 is very weak. H2O increases Ioff, decreases Ion/Ioff and shifts VT negatively. The component of the pollutant in air, NO2 is found to bring a positive shift of VT, and an unchanged Ion/Ioff.

Generation of kHz Pulsed Molecular Beams and Its Application in Experimental Research of Strong Field Atomic and Molecular Physics

XU Shaohua;WANG Peng;YANG Hong;WU Chengyin

2015, 51(4):  591-595.  DOI: 10.13209/j.0479-8023.2015.014

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The authors successfully generated pulsed molecular beams with high repetition rate by using a cantilever piezo valve, and the highest repetition rate could reach 3 kHz. The interaction between intense femtosecond laser fields and nitrogen molecular beams were studied, in which the molecular beams were produced by cantilever piezo valve. Strong fluorescence emissions, which could be assigned to N2 +(B-X), were observed. The performance of pulse valve was characterized based on the measurement of the fluorescence emission as a function of the repetition rate and the time delay of the pulsed valve. The results demonstrate that pulsed molecular beams can be generated with high quality and high repetition rate. The combination of such pulsed molecular beams and high-frequency kHz femtosecond lasers will promote the experimental study of molecular dynamics driven by intense femtosecond laser fields.

Molecular Dynamics Simulation of Tungsten Ablation under Transient Heat Flux

ZHU Yizhou;YAN Sha?;XUE Jianming;HE Shukai;ZHANG Boyao;WANG Yugang

2015, 51(4):  596-600.  DOI: 10.13209/j.0479-8023.2015.015

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The authors adopt molecular dynamics simulations to get a basic physical image of the tungsten ablation phenomenon induced by intense pulsed ions irradiation. A one-dimension heat transfer model is set up and a series of simulations with different pulse energy fluences are applied. Ablation threshold and ablation depth are calculated and compared with thermal dynamic theoretical values. Energy allocation condition of the simulation system are discussed, which depends on whether the pulse energy exceed ablation threshold. Based on the calculation results, the authors drew a preliminary profile of tungsten ablation under a transient high heat flux brought by energetic ions.

The Mode Locking of the Booming Sand Dunes

LIN Guanming;ZHAO Xiaohu

2015, 51(4):  601-605.  DOI: 10.13209/j.0479-8023.2015.055

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A two layer model is developed to investigate the movement of a single round particle. The reference layer is set as a slope with the repose angle 30°, and is covered regularly with round particles with the same diameter. The free layer in which the same diameter can move freely is just on the reference layer. A periodic rolleject- collide movement is found, and the frequency is 0.39 g/D , which is independent of the initial velocity and close to the velocity gradient. The constant projection angle is 51.2° and the spin angular velocity is 16 r/min. This self-hold of frequency determines the sands in the free layer to move forwards integrally, and may be the basic acoustic mechanism of the booming sands.

Research on High-Speed Subway Train Passing through the Station

JIN Hai;YANG Liguo;CHEN Kai

2015, 51(4):  606-612.  DOI: 10.13209/j.0479-8023.2015.052

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Dynamic mesh method based on numerical simulation method of CFD was adopted. The changes of wind velocity in pedestrian level were calculated when the train entered, passed through and left the station at high speed (80 km/h). 63 monitor points at the pedestrian height were arranged to assess the influence of train wind quantitatively. The range for the pedestrian safety and comfort were given based on the proper wind comfort criteria, which could provide useful guide to platform design

Wind Tunnel Investigation on the Pedestrian Wind Environment around High-Rise Buildings

JIN Hai;YANG Liguo;CHEN Kai

2015, 51(4):  613-619.  DOI: 10.13209/j.0479-8023.2015.053

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The pedestrian wind environment around a commercial center in Beijing was investigated in the wind tunnel. The pedestrian level wind velocity distributing could be attained by analyzing the result of test points arranged around the models. Based on the pedestrian level wind comfort criteria, which categorized different ranges of wind velocity as being appropriate for certain types of pedestrian activities and gave the corresponding acceptable frequencies of occurrence, the pedestrian wind environment was assessed quantitatively combined with the local wind climate statistic records. Some useful guide was provided to improve the comfortability in the potential uncomfortable or dangerous locations.

Ozone Source Apportionment of Typical Photochemical Pollution Episodes in the Pearl River Delta in Autumn

CHEN Hao;WANG Xuesong;SHEN Jin;LU Keding;ZHANG Yuanhang

2015, 51(4):  620-630.  DOI: 10.13209/j.0479-8023.2015.089

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The Comprehensive Air Quality Model with extensions (CAMx), a 3-D regional chemical transport model, was used to simulate ozone concentrations in the Pearl River Delta (PRD) in November, 2009. Ozone Source Apportionment Technology (OSAT) was applied to investigate sources of two typical ozone episodes and a clean day as comparison. The results showed that emissions from urban Guangzhou and Dongguan mainly contributed to local areas and the southwestern part of PRD (15–30 μL/m3), while emissions from Shenzhen Baoan district (15–25 μL/m3) mainly affected the Pearl River Estuary. Mobile sources and solvent usage sources were two major contributors to ozone formation and had an influence in most areas of the central and western PRD. Mobile sources could contribute as much as 50 μL/m3 hourly ozone concentration to the boarding area of Foshan and Guangzhou. Trans-boundary import of ozone made episodes more likely to occur in PRD under unfavorable weather conditions, however, the ozone precursors emitted within the PRD region were the main cause of high ozone concentrations during ozone episodes. As a result, the strategies on controlling emissions within the PRD region are the key to the reduction of ozone pollutions in PRD.

Research on Construction Land Evaluation Based on Land Ecological Sensitivity Analysis

ZHANG Shiyi;FENG Changchun;LIU Xueping;WANG Fuliang;XIE Danxing

2015, 51(4):  631-638.  DOI: 10.13209/j.0479-8023.2015.071

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The methods of land ecological sensitivity analysis were discussed, based on the concept of “protection goes first” to the construction land pattern. With a combination of comprehensive index method, fuzzy evaluation method and RS/GIS approach, an integrated method of construction land suitability assessment was proposed. It offers three factors that mainly influence the construction land-use environment including land ecological sensitivity, natural condition and social economy environment, and it introduces the fuzzy membership functions to improve the model algorithm. The evaluation results would hierarchically display different land ecological sensitivity endowment and land-use environment, which leads to analyze the construction land spatial distribution in a land ecological security pattern. Taking Xiangjiang New District of Changsha City as a case, 14 indexes were chosen in accordance with the local conditions, to assess construction land suitability of this area. The results objectively show the region’s land ecological environment and land-use condition, and give an ecological security spatial arrangement of the construction land pattern, which can provide guidance to land-use planning of the “resource-economical and environment-friendly” society.

Calculation of Full Carbon Emission and Evaluation of Carbon Emission Performance

ZHANG Xuehua;LI Xiang;YE Wenhu;ZHANG Baoan

2015, 51(4):  639-646.  DOI: 10.13209/j.0479-8023.2015.073

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A full carbon emission calculation method is proposed, whose accounts include energy consumption carbon emission, potential carbon consumption of biomass resource consumption, and potential carbon consumption of waste emission. The solar emergy is used as a tool of the same normalized dimension for calculating the amount of full carbon emission. Based on the full carbon emission calculation, population carrying capacity of one unit carbon emission, economic output of one unit carbon emission, and per capita disposable income of one unit carbon emission are considered into one package to construct an index to evaluate the carbon efficiency and development coordination level of a region, and the index is named carbon emission performance integrated index. Taking Beijing and Chongqing as examples, an assessment is made from 2001 to 2011 with the result that the proportion of energy consumption carbon emission in the full carbon emission of the two cities is raised continuously, which indicates that even in the view of full carbon emission, energy consumption is still the main factor affecting carbon emission; however, the effects from modes of both life and production on carbon emission also cannot be neglected. Compared with the traditional carbon efficiency evaluation with only energy carbon emission and carbon production rate considered, the carbon integrated performance evaluation based on “full carbon emission calculation” can fairly and objectively reflect carbon performance of a region, thus it provides a scientific method to identify the responsibility of regional carbon emission reduction.

Estimating Air Pollutants Emissions from Open Burning of Crop Residues in Jianghan Plain

LI Jianfeng;SONG Yu;LI Mengmeng;HUANG Xin

2015, 51(4):  647-656.  DOI: 10.13209/j.0479-8023.2015.088

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To investigate the emissions from open burning of crop residues in Jianghan Plain by using the Emission Factor Method, household surveys were conducted to obtain the percentages of crop residues burned in fields. Household survey statistics, GLC2000-China product and MODIS active fire products (MOD/MYD14A1) were used to analyze the temporal-spatial distribution of crop residues burning emissions in Jianghan Plain. The results gave a total emission of 73.3 Gg PM2.5, 18.6 Gg OC, 3.27 Gg BC, 7763 Gg CO2, 238 Gg CO, 10.6 Gg CH4, 28.6 Gg NMHCs, 0.382 Gg N2O, 5.74 Gg NH3, 8.26 Gg SO2 and 17.1 Gg NOx from the open burning of crop residues, in 2010, which happened most frequently in May, September and October. Among all subregions, Jianli County contributed the most to the total crop burning emissions, followed by Xiantao and Tianmen City, while Jingzhou municipal district had the highest PM2.5 emissions per unit area. Rice straw was the dominant source of crop burning emissions among all types of crop residues, followed by rape straw and wheat straw.

Effects of Nutrient Additions on Community Biomass Varied among Different Grassland Ecosystems of Inner Mongolia

HE Xing;MA Wenhong;LIANG Cunzhu;HONG Mei;CHAI Xi;ZHAO Bayinnamula;ZHANG Yuping;YANG Shaohuan;Zhang Jiaxin;XIN Xiaoping

2015, 51(4):  657-666.  DOI: 10.13209/j.0479-8023.2015.090

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In order to compare the response of community biomass to nutrient additions among different grassland ecosystems, the authors established nutrient addition experiments on three grassland ecosystems along the climate gradient, including meadow steppe, typical steppe and desert steppe in Inner Mongolia. On the basis of the threeyear experiment, the impacts of different nutrients (N, P) on different nutrient gradient (N: 10, 5 and 2.5 g/m2; P: 10 g/m2) on above- and belowground biomass of these grassland ecosystems was analyzed. The results show that nitrogen leads to a significant increase in the aboveground biomass of grassland in Inner Mongolia by 27% to 53.3%, an average increase of 37.8%. In addition, the response of biomass to N addition increases with the N gradients. Belowground biomass has a less response to fertilization than aboveground biomass. There is an average of 10.2% increase in the total biomass of grassland community in response to N addition. Biomass responds to P addition less deeply than N addition. Furthermore, the response of biomass to nutrient addition varies among three grassland ecosystems. In arid desert steppe, community biomass is more sensitive to N limitation than the typical steppe and meadow steppe. N addition reduces belowground biomass and R/S ratio in meadow steppe and desert steppe, whereas promotes the values in typical steppe. In contrast, nutrient additions have relatively less and insignificant impacts on the root distribution of temperate grasses. These observations indicate that nutrient addition has different effects on community biomass under different environmental conditions, which means it is necessary to consider the changed response of different grassland ecosystems to nutrient addition in the carbon cycle models budget and grassland management.

Comparative Study on Pb(Ⅱ), Cd(Ⅱ), As(Ⅲ), Cr(Ⅵ) Resistance Characteristics of Fungus

YANG Zhenxing;TIAN Congkui;DANG Chenyuan;CHANG Fang;NI Jinren

2015, 51(4):  667-676.  DOI: 10.13209/j.0479-8023.2015.092

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19 fungus were isolated from two different soil environments and a comparative analysis of their heavy metal tolerance was conducted. Among them, 18 fungus, i.e. Aspergillus sp., Trichoderma sp., Penicillium sp., Fusarium sp., were isolated respectively from the contaminated soil of Shuikoushan nonferrous metals mine in Hunan Province; 2 fungus, identified as Aspergillus niger., were isolated from non-contaminated soil in green land located in Langfang Economic Development Zone. Fungus isolated from the contaminated soil and noncontaminated green land as well as those reported previously are compared in terms of their heavy metal resistance characterized with the minimal inhibitory concentrations (MICs). As results, mechanism of fungal resistance of high concentrations of heavy metals was revealed. The fungus of heavy metal resistance primarily relies on the sites of their isolation, metal species, fungi species and metal speciation. Considering their high heavy-metal tolerance, e.g. MICs 144 mmol/L for Pb(Ⅱ), 36 mmol/L for Cd(Ⅱ) and Cu(Ⅱ), and 72 mmol/L for As(Ⅲ), the isolated fungus perform excellent and thus have higher potential for soil restoration.

Planning and Design Modes of Land Consolidation Based on Analysis of Landscape Pattern and Restrictive Factors

TANG Xiumei;REN Yanmin;PAN Yuchun

2015, 51(4):  677-684.  DOI: 10.13209/j.0479-8023.2015.097

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Taking Nanlv land consolidation project in Tunchang County of Hainan Province as an example, the authors explored the method based on analysis of landscape pattern and restrictive factors. Firstly, the landscape pattern of landscape scale and type scale is analyzed by ArcGIS and FRAGSTAS. Then, using the units of agricultural land classification as the unit of analysis, the restrictive factors are analyzed by the method of combination of grading factors. The combination types of grading factors and their restrictive degree of each unit is gotten. Lastly, based on the result of analysis of landscape pattern and restrictive factors, planning and design modes of land consolidation are proposed. Among them, the spatial layout planning is to determine the pattern of land use of the land consolidation project, including the spatial location and quantity ratio, and the position of the land consolidation project. The ecological design of land consolidation is to design the land types and land consolidation project based on ecological protection, including the plots, field roads, the irrigation canals and ditches. The research can provide a scientific basis for the planning and design modes of land consolidation in tropical plateau area.

Relationship between Shrubs Distribution and Slope: A Case Study in Mountains of the Beijing-Tianjin-Hebei Region

WANG Tao;HAO Qian;LIU Hongyan

2015, 51(4):  685-693.  DOI: 10.13209/j.0479-8023.2015.091

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Shrublands in the Beijing-Tianjin-Hebei region were selected to unveil relationships between the area percentage of shrubland and the slope angle. Gridded data of vegetation and slope angle were correlated for the whole region as well as different climatic regimes with piecewise regression analysis. The results show that there is a tipping point on the fitted curve between percentage of shrubs and slope angle, instead of a monotonous linear fit. On gentle slopes, percentage of shrubs increases with the increase of slope angle, which might be caused by the decrease of human cultivation. On steep slopes, there are divergent patterns, percentage of shrublands except that dominated by Vitex negundo var. heterophylla and Zizyphus jujuba var. spinosa decreases with the increase of slope angle, which might be caused by resource limitation. Percentage of this shrubland type does not show trend of decline with slope angle increase, which might be caused by its distribution on low elevations and its adaptation to varied habitats. In addition, the tipping point mostly fixes around 15 degree of slope angle when the region is taken as a whole; it changes under different climatic regimes.

Assessment of the Trend of Heavy PM2.5 Pollution Days and Economic Loss of Health Effects during 2001–2013

MU Quan;ZHANG Shiqiu

2015, 51(4):  694-706.  DOI: 10.13209/j.0479-8023.2015.074

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In order to explore the historical annual heavily PM2.5 polluted days and their health loss, the study constructs a daily air quality dataset for 31 provinces of China from 2001 to 2013. Further, it evaluates the health impacts especially the premature death and the economic loss due to the heavy PM2.5 pollution days of each year since 2001 for each province, by applying the latest results of dose-response in epidemiologic studies and taking account of the age structure of population as well as valuation approaches. The result shows that since 2001, heavily polluted situation (above the defined threshold, here the 2nd grade of air quality standard is applied for practical reason) for PM2.5 occurred in 71 percent of the provinces on a yearly basis. Although the average concentration of heavily polluted days did not have much variations during the thirteen years and the trend went down during 2001–2012 in terms of occurrence, heavily polluted situation increased dramatically in frequency in 2013. As a result, the proportion of heavily polluted days in 2013 was the highest during 2001–2013. It is estimated that over 65000 premature deaths was caused by heavy PM2.5 pollution days in 2013, which can be assessed as the 28.1 billion Yuan loss in economic term, 54 percent of the total economic loss in these thirteen years equivalently. The surge of economic loss in 2013 was attributed to the lasting heavy PM2.5 pollution in January 2013 and eight provinces in eastern and middle China.

Spatialization of Demographic Data at Medium Scale Based on Remote Sensing Images: Regarding Beijing-Tianjin-Hebei as an Example

WU Jiansheng;XU Duo;XIE Wudan;PENG Jian

2015, 51(4):  707-717.  DOI: 10.13209/j.0479-8023.2015.100

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This study selects Beijing-Tianjin-Hebei region as the study area and attempts to realize the population spatialization with the data of DMSP/OLS, land use, socio-economic and ecological environmental factors related to population distribution at the medium scale. Firstly, the authors obtain the census data of Beijing-Tianjin-Hebei region in 2010, and then calculated the probability coefficient based on these factors (selected roads, railways, rivers, slope, land use and nighttime light), and finally assign the census data to each pixel using all related variables and their probability coefficients with the software of geographic information system (GIS). City census data was chosen to test the research result, and the results showed that the accuracy rate of the population spatialization in the Beijing-Tianjin-Hebei region is more than 74% in the urban scale. The method for population spatialization can be well applied to the spatialization of demographic data at medium scale.

Characteristics of Cloud Occurrence Frequency and Cloud Base Height in Summer over Beijing

GUO Jinghan;XUE Huiwen;LIU Xiaoyang

2015, 51(4):  718-724.  DOI: 10.13209/j.0479-8023.2015.002

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Cloud occurrence frequency (COF, the ratio between the number of records with detected clouds with respect to the total available records) and the distribution of COF within one day below 8 kilometers in summer from 2007 to 2009 over Beijing is studied. Cloud base height (CBH) of one layer clouds, the characteristics of convective CBH and the relationship between convective CBH and relative humidity (RH) measured on the surface are further studied. Results show that cloud occurrence frequency is about 12% in summer over Beijing. Clouds are more likely to occur at night than in the afternoons. The distribution of CBH has one peak at 700 (±50) meters and low clouds (ranging up to 3000 meters) account for 82% of all clouds. Convective CBH ranges from 400 to 2000 meters for the cases studied, but do not vary much within each day. CBH can be conveniently derived from linear relationship between CBH and surface RH based on Adiabatic Parcel Model. Mean relative standard deviation of CBH is 0.321.

Variations in Total Ozone Observed at Longfengshan and Waliguan and Its Relationship with Synoptic Process

TU Xiaolin;ZHENG Xiangdong;ZHAO Chunsheng

2015, 51(4):  725-734.  DOI: 10.13209/j.0479-8023.2015.003

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Longtime in-situ measurements of total ozone from the ground-based Brewer observatories at Longfengshan in Heilongjiang Province and Waliguan in Qinghai Province were analyzed together with the according geopotential height data from NCEP R1 reanalysis series. Abnormal day-to-day fluctuations in the total ozone amount were found at times, which were analyzed in respect to synoptic processes. Results show that the impact of synoptic conditions is highly related to the variation of the total ozone amount. The anomaly in total ozone amount mostly appears in winter and spring (from November to May in the following year). The abnormal high total ozone amounts (the first kind of abnormal data points) always occur when the station is at the rear of the near surface (1000 hPa) cyclone with a simultaneous air pressure trough approaching in lower stratosphere (250 to 70 hPa). The abnormal low total ozone amounts (the second kind of abnormal points) always occur when the station is behind a near surface anticyclone with a simultaneous air pressure ridges approaching in lower stratosphere. The anomaly in total ozone amount can be considered as a signal for the upcoming transition between near surface cyclone and anticyclone.

Coupled Model Studies of the Topography Effect on the Global Meridional Overturning Circulations

SUN Yu;YANG Haijun

2015, 51(4):  735-744.  DOI: 10.13209/j.0479-8023.2015.006

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The atmospheric and oceanic meridional circulation in both the flat and real world are studied using the fully coupled Community Climate System Model version 1.0 (CESM1.0). Two global mean climate are obtained from two topography experiments named Flat (the land of the whole planet is set as 10 meters above sea level without ups and downs) and Real (just simulated to the real world). There is significant difference in both the atmospheric and oceanic meridional circulation relative to the real world. Hadley Cells is more symmetric as a result of the southward shift of the center of the time averaged atmospheric convection. The oceanic meridional overturning circulation is greatly increased with deep PMOC (the Pacific meridional overturning circulation) and THC (thermohaline circulation) replacing AMOC (the Atlantic meridional overturning circulation). These are caused by the decrease in both the atmospheric and oceanic heat transport from equator to Arctic in mid-high latitude of the Northern Hemisphere (NH). At the same time, it is found that the air rising is weakened and much colder climate is observed in the flat world, which result in the increased sea water density in the Pacific opposite to the Atlantic.

In-situ Simulation Experiment of Carbonate-Hydrogen Sulfide Equilibrium System and Its Geological Significance

ZHANG Shanming;QIN Shan1;LIU Bo;WU Xiang, ZHANG Xuefeng;LIU Jianqiang;TIAN Yongjing

2015, 51(4):  745-754.  DOI: 10.13209/j.0479-8023.2014.180

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The interactions between carbonate and H2S saturated acid fluid at various temperatures and pressures in-situ conditions were simulated using hydrothermal diamond-anvil cell equipment combined with Raman spectroscopy. The heating process is from room temperature to 230?C and then the system is cooled to room temperature again. Experimental results clearly demonstrate that carbonate minerals present much precipitation from room temperature to 140?C and little precipitation from 140?C to 230?C. Carbonate trends to precipitate with the increase of temperature and pressure, and dolomite is more stable than calcite and limestone. But in the cooling process carbonate suffers from little dissolution. So in the burial process, carbonate trends to precipitate, and the rapid closed burial and slow uplift process is beneficial to form high quality reservoirs in the deep closed condition. Fault and magmatic hydrothermal activities may break the closed system, which needs further study.

An Atomic Model of Spatiotemporal Query Based on Object-Oriented Snapshot Model

LIU Yuefeng;KANG Wei

2015, 51(4):  755-762.  DOI: 10.13209/j.0479-8023.2015.008

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By analyzing the fundamental spatiotemporal characteristics of spatiotemporal objects, six query primitives, which are temporal range, spatial range, spatiotemporal range, temporal relation, spatial relation and attribute state, are proposed based on object-oriented snapshot model. Centered on time, atomic queries are defined, and approaches to constructing complex queries from these atomic queries are proposed. On the purpose of rendering the proposed query model more systematic and adaptable, application semantics are not considered in defining query primitives and atomic queries. In addition, owing to its clear expressiveness in GIS, the model possesses considerable implementability and can serve as the foundation and basis of implementations of spatiotemporal query interfaces in temporal GIS.

Hysteresis Effect in the Temperature and Precipitation Changes in Numerical Simulation with Varying Greenhouse Gas

SUN Daoxun;YANG Haijun

2015, 51(4):  763-771.  DOI: 10.13209/j.0479-8023.2015.004

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A series of numerical simulations are conducted (using GFDL CM2.1) to investigate the global mean precipitation and temperature change in response to climate variation. Experiments under different carbon dioxide (CO2) forcing indicate an obvious precipitation hysteresis. There is a significant linear relationship between global mean precipitation and surface temperature, but precipitation is also influenced directly by CO2 concentration. During the experiments in which CO2 concentration rises up and then falls back, precipitation change lags behind surface temperature, which leads to the precipitation hysteresis. While CO2 increasing, the enhanced greenhouse effect will lead to immediate intension of atmospheric long-wave absorption, which will bring net radiative energy income to atmosphere. To balance the energy budget, upward latent heat has to be restrained, so the additional CO2 has inhibiting effect on precipitation. The subsequent warming mainly induces increasing in outgoing long wave radiation at TOA and backward long wave radiation at surface, which is equivalent to a radiative cooling for atmosphere, and then causes precipitation rising. While CO2 decreasing, on the contrary, the subdued greenhouse effect tends to intensify precipitation and the temperature reduction will reduce the precipitation. Different effects on precipitation from temperature and CO2 determine the precipitation hysteresis.

Review

A Review of Parameterization Methods for Downward Shortwave and Longwave Radiation on the Surface

PENG Lichun;LI Wanbiao;YE Jing;CHENG Dong;LI Yuming;CAO Lijia

2015, 51(4):  772-782.  DOI: 10.13209/j.0479-8023.2014.181

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Research progresses in parameterization schemes for estimating downward shortwave and longwave radiations are reviewed by use of satellite data and ground-based routine observations in recent years. Based on a comprehensive analysis of the relevant literatures, the theoretical backgrounds of downward shortwave and longwave radiation parameterization schemes are described. According to the clear-sky and cloudy-sky conditions, the radiation parameterization schemes are summarized and their advantages and disadvantages in the practical application are reviewed. Under clear-sky conditions, the main parameterization schemes of downward shortwave radiation are statistical methods and radiative transfer models; the longwave radiation parameterization schemes are mainly single-parameter and dual-parameter methodologies. Under cloudy-sky conditions, radiation parameterization schemes are mainly limited to the determination of cloudiness. The limitations of estimating downward shortwave and longwave radiation on the surface are the selections of appropriate parameterization scheme that need considering land cover types and the attainment of meteorological observations and satellite remote sensing data. In the future, the relatively promising estimation approach is pointed out by combination of polar-orbiting and geostationary satellite remote sensing data.