Table of Content

20 July 2011, Volume 47 Issue 4

Previous Issue    Next Issue

Computation of Channel IR4 Albedo and Its Applications in Precipitation Analysis

WANG Lingxiao,WANG Hongqing,WANG Yu,LIN Yinjing

2011, 47(4):  599-606. 

Asbtract ( )  

Related Articles | Metrics

Based on the derivation of the formula of channel IR4 albedo, the data including the brightness temperature and the albedo of channel IR4 was applied to analyze a case of the precipitation in summer in Beijing. The results show that channel IR4 albedo will increase and then decrease significantly before the precipitation is generated. Channel IR4 has an earlier feedback on the precipitation than long-wave infrared (IR1) channel and water vapor (WV) channel. In the weak echo phase after heavy precipitation, the brightness temperatures of channel IR1 and WV will continue to decrease while the temperature and albedo of channel IR4 continue to increase. Correspondingly, the appearance of the minimum brightness temperatures of channel IR1 and WV is later than the appearance of the maximum echo of the weather radar.

A Study on the Long-Term Correlation of Cloud Amount

GAO Jianhua,XUE Huiwen

2011, 47(4):  613-618. 

Asbtract ( )  

Related Articles | Metrics

The authors use the detrended fluctuations analysis (DFA) to analyze the ISCCP cloud amount data at four locations: Beijing, Shanghai, Western Pacific, and Eastern Pacific. It is found that cloud amount indeed has power-law correlation in large time scales, which indicates that the cloud amount has strong long-term correlation in the locations studied. The crossover over the ocean appears later than that over the continent.The long-term correlation of the the cloud amount over the Western Pacific is stronger than the Eastern Pacific’s.

Correlation Analysis between PM10 Mass Concentration and Meteorological Elements of Atmospheric Boundary Layer in Beijing Area

GUO Li,ZHANG Yankun,LIU Shuhua,LI Ju,MA Yanjun

2011, 47(4):  607-612. 

Asbtract ( )  

Related Articles | Metrics

The exploration analysis and correlation analysis were done using the Air Quality data and synoptic radio sonic data in Beijing, 2007 to illustrate the relationship between the spatio-temporal distribution of PM₁₀ mass concentration and the meteorological condition and its diurnal and seasonal variation, The results show that the synoptic condition in the atmospheric boundary layer dominates the accumulation, transportation, dilution and sinking processing. There is a significantly negative correlation between PM₁₀ mass concentration and synoptic conditions such as height of Atmospheric boundary Layer (ABL) and wind speed while positive correation between PM₁₀ mass concentration and temperature near ground surface pressure. Besides, the correlation varies with seasons; The relationship between PM₁₀ mass concentration and wind speed can be described by a U-curve which obey a binomial model. The PM₁₀ mass concentration observation data in November 2007 shows a minimum records with wind speed of 4.1 m/s.

Application of Adaptive Narrow Beam to HF Antipodal Propagation

WEN Miaowen,LI Yanli,DUAN Xiaohui,JIAO Bingli

2011, 47(4):  581-586. 

Asbtract ( )  

Related Articles | Metrics

The authors introduce equivalent antipodes at the receiver to transform the antipodal propagation to several equivalent point-to-point communication systems. Since many communication directions are permitted in the antipodal propagation, especially each of which carries on different propagation modes with respective time delay and received power, the channel experiences a strong characteristic of frequency selective fading. In order to strengthen the received power and increase the coherence bandwidth, an adaptive antenna array is applied in the transmitter with narrow beams spatially concentrating the transmission energy on the main path and suppressing the other multipath resulting in delay spread. Simulation results verify the efficiency of this proposal.

Adaptive Kalman Filter Based Navigation Algorithm for Single-Frequency Precise Point Positioning

LU Chenxi,TAN Yunhua,ZHU Bocheng,ZHOU Lezhu

2011, 47(4):  587-592. 

Asbtract ( )  

Related Articles | Metrics

A real-time resolving algorithm for single-frequency precise point positioning is presented. Based on Kalman filter, the observations on single frequency are processed in kinetic situations, and good precision can be obtained without static initialization. Innovation-based adaptive Kalman filter is improved to make the algorithm precise and robust in kinetic situations. In order to correct ionosphere influence effectively, the ionosphere delay on zenith is estimated in filtering process using spherical shell model when more than 5 satellites are available. Applications on practical data and kinetic simulations prove the effectiveness of this algorithm in both static and kinetic situations.

Top-Down Design for MASH21 Sigma-Delta Modulator

GE Binjie,WANG Xin’an,ZHANG Xing,FENG Xiaoxing,WANG Qingqin

2011, 47(4):  593-598. 

Asbtract ( )  

Related Articles | Metrics

The authors propose a top-down design process for MASH21 modulator. In system level, coefficient scaling is used to limit integrator’s output; in circuit level, integrator transient modeling is used to analyze the effect caused by OP’s non-ideality, and get the optimized design region for SNR, area and power. A MASH21 modulator for digital audio application is designed to verify the proposed design criteria. This experimental prototype is implemented with TSMC18MMRF, operates under a single 1.8 V power supply, and achieves a measured SNDR of 91dB.

Applications of GPS Radiosondes and Aircrafts for a Precipitation Analysis in Zhangjiakou Region during the Spring of 2009

QIU Heng,FANG Wen,WANG Xiaobin,LIN Hongtao

2011, 47(4):  619-626. 

Asbtract ( )  

Related Articles | Metrics

Data from Vaisala RS-92 GPS radiosonde, and observed by aircraft are analyzed to research the feature of one spring stratiform cloud precipitation of 2009 at Zhangjiakou. Analyses of quasi-saturation areas, potential instability districts and the evolution of the wind field show the weather characteristics of this event. The result shows the reason of the water vapor variation through its transportation, total content variation and uneven distribution along the altitude. Furthermore, comparison between the Vaisala RS-92 GPS radiosonde data and the aircraft observed cloud physics data shows they can complement each other.

Multi-Scale Fluctuation of European Temperature Revealed by EEMD Analysis

WANG Bing,LI Xiaodong

2011, 47(4):  627-635. 

Asbtract ( )  

Related Articles | Metrics

Ensemble empirical mode decomposition (EEMD), a newly developed nonlinear data analysis method, is employed to derive climate change signals, such as annual cycle, low-frequency components and trends, etc. The data sets for the analysis are the well-homegenized, longer than 150 years, daily temperature series of five stations in Europe. The decomposed results indicate that there are three main time scales, e.g. interannual, interdecadal and century scales, for the low-frequency variations of all five stations. The intensities of the annual cycle were weak during the two warm periods: 1910?1940 and the last 30 years since 1970. And the weak trend was more obvious in the last 30 years. In addition, summers become more longer and winters shorter since the late of 1970s compared with that of warm period in 1910?1940.

Retrieval of Aerosol Optical Depth from Fengyun-2C Geostationary Satellite Observation: Theory and Implementation

REN Tong,GAO Ling,LI Chengcai,MAO Jietai,LI Wanbiao,SHI Guangming,YANG Dongwei,WANG Lei

2011, 47(4):  636-646. 

Asbtract ( )  

Related Articles | Metrics

How to use the measurement from the visible channel of Chinese Fengyun-2C geostationary satellite to retrieve aerosol optical depth (AOD) is discussed. By calculating mean surface reflectance at the same local time of each day in one month, the randomicity of the estimated surface reflectance can be reduced. The influence of different values of AOD assumed in the cleanest days on the quality of final AOD product is analyzed. In addition, the data in May 2008 was used to test the proposed algorithm and the results were compared with the AOD product from six AERONET sites in East Asian and MODIS AOD product respectively. Last, the error sources were analyzed in the retrieval of AOD from FY2C satellite, and the corresponding possible schemes to decrease the error influence and improve the quality of FY2C AOD product were investigated. The comparison indicates that in East Asian the AOD product can display the pattern of aerosol distribution, but overestimates the values of AOD in southwest of China and low latitude areas, and underestimates the values of AOD in east of China.

Uncertainty of the Numerical Simulation of a Failure Weather Forecast Case during the Paralympic Games 2008

WANG Yichuan,ZHANG Qinghong

2011, 47(4):  647-654. 

Asbtract ( )  

Related Articles | Metrics

A squall line hit Beijing on Sept. 14, 2008 when thunder, light and strong winds was observed in the urban areas, however, the weather forecast for that day failed. The weather research and forecasting model (WRF) and the ARPS (advanced regional prediction system) data assimilation system (ADAS) are used to analyze the sensitivity of model horizontal resolution and initial condition contributed by different kinds of observations (FY2C satellite data, MICAPS data and GTS (global telecommunication system) data). Results show that there is no precipitation at all in Beijing in the simulation with a horizontal resolution of 15 km. While, for the simulation with a horizontal of 5 km, the precipitation can be simulated except that the area and intensity of the rainfall is different. There is no precipitation in the urban area in the control experiment without data assimilation. The simulated precipitation location is improved after using the ADAS data assimilation system. A MICAPS sounding in the Hetao area brings stronger northeast winds at lower level in the initial condition compared with control run in which the simulated squall line moves to the north of Beijing.

Analysis of the Surface Temperature over Keerqin Sand Aera in Inner Mongolia

ZHANG Peng,ZHANG Hongsheng,DU Jinlin,LIU Huizhi

2011, 47(4):  655-663. 

Asbtract ( )  

Related Articles | Metrics

Using the micrometeorological data obtained over the moving sand dune in Keerqin sand area in Inner Mongolia in summer of 2001 and spring of 2002, the surface temperature was determined and the characteristics were analyzed over the sand dune area. The idea is using discrete Fourier transform on the temperatures of different layers and applying soil heat conduction equation. The results are that soil temperature conductivity ratios which are calculated from the decline of the soil temperature amplitude and phase difference agree well under the assumption of layered homogeneity. The surface temperature was calculated using the relationship of the soil temperature conductivity ratios at different depths and the amplitude and phase of dominant and harmonic frequencies of soil temperature. The surface temperatures calculated from observed soil temperatures at 5 cm and 10 cm depth show a good agreement. The amplitude of soil temperature waves decreases exponentially with depth. The diurnal variation of soil temperature at 80 cm is small.

Numerical Simulation and Experimental Comparison on Atmospheric Pollution Chemical Accident Hazard Predicting(CDM)

HUANG Shunxiang,CHEN Haiping,LIU Feng,LIU Shuhua,ZHU Fengrong

2011, 47(4):  664-670. 

Asbtract ( )  

Related Articles | Metrics

The concentration and dose model on chemical agents diffusion or the toxic clouds diffusion model over complex terrain(CDM) is established, which can be used to assess and predict atmospheric pollution chemical accident hazard, and provides fast, intuitionistic and quaniticational decision information for emergency. Contaminated field, contaminated rate, contaminated area, and contaminated depth may be computed in a few minutes. The comparison of field experiment results with numerical simulation results shows that contaminated field, contaminated rate, and contaminated depth are consistent on the whole, and the relative error of dose at different distance is less than one time. The mean relative error is 20.6%, and the relative error of contaminated depth are ?26.3% and 10.2% respectively at 0.66 g?s/m3 and 0.24 g?s/m³ dose. The comparison of CDM simulating results with water tank experiment results shows that they are similar highly in neutral atmosphere or stable atmosphere.

A Method of Inferring Ground Level NO2 Using Satellite-Borne OMI Observations

DING Yuyu,PENG Li,RAN Liang,ZHAO Chunsheng

2011, 47(4):  671-676. 

Asbtract ( )  

Related Articles | Metrics

Ground-level NO₂ concentrations in Shanghai between May 2006 and August 2008 are estimated using the tropospheric NO₂ column concentration data of Ozone Monitoring Instrument (OMI) onboard AURA. In-situ measurements of surface NO₂ concentrations of Xujiahui, Shanghai are corrected using global 3-D chemical transport model MOZART-2, and are used to validate the surface NO₂ concentrations derived from tropospheric columns. The results show a significant correlation between monthly mean OMI derived surface NO₂ concentrations and in-situ NO₂ surface concentrations (R²=0.88), indicating that it is reliable to infer ground-level NO₂ concentration from NO₂ tropospheric column concentration.

Application of Orientation Angle Compensation to Fully Polarimetric SAR Data for Bare Soil Moisture Estimation

YUAN Weilin,QIN Qiming,DU Shihong,SHEN Xinyi

2011, 47(4):  698-702. 

Asbtract ( )  

Related Articles | Metrics

JPL/AIRSAR L-band polarimetric SAR data are used to calculate the orientation angle through theoretical model and circular polarization algorithms. After orientation angle calibration, RMSE of backscattering coefficient of HH and VV polarization and co-polarization ratio versus AIEM predictions separately reduce from 1.93, 1.37, 1.89 dB to 1.62, 1.24, 1.62 dB and 1.39, 1.19, 1.46 dB, respectively. The authors demonstrate the validity of orientation angle compensation to fully polarimetric SAR data for bare soil moisture estimation.

Application of the RZB Borehole Strainmeter in Crustal Stress Observation at the Eastern Margin of the Tibet Plateau

LI Tao,CHEN Qunce,OUYANG Zuxi,NING Jieyuan,CHEN Zheng,WU Liheng

2011, 47(4):  677-683. 

Asbtract ( )  

Related Articles | Metrics

The authors introduce a new generation RZB borehole strainmeter and its application in crustal stress observation. The preliminary analysis of the monitoring data from the RZB-3A borehole strainmeter installed in crustal stress station of Jiangyou in Sichuan show that the resolution of the observing system is better than 10^-9 strain megnitude. The borehole strainmeter not only recorded strain tide, also recorded broadband strain seismic wave. Especially, because of the superiority of the 4-component borehole strain observation, the obtained data show that RZB-3A borehole strainmeter has high measurement accuracy of plane strain in crustal horizontal strain field of the area around the observation station. Therefore, it is significant to reveal the relationship between the activity of stress field and earthquake to use the new multi-component borehole strainmeter to develop crustal stress continuous observation in the eastern margin of the Tibet Plateau.

A Simple Geometry Method for Analyzing Angle Relationship of Fault-Bend Fold Model

CAI Zhenzhong,HUANG Shaoying,WANG Yueran

2011, 47(4):  684-688. 

Asbtract ( )  

Related Articles | Metrics

By analyzing on the geometry of fault-bend fold and the quantitative, a new geometry method is put forword for analyzing the angle relationship of fault-bend fold with circle and triangle. Considering on four common situations, including case of γ and θ are known, case of γ and β are known, case of θ and β are known, and case of θ and φ are known, the authors demonstrate their corresponding geometric construction method. Being used in an example and compared with the result of other methods, it shows that our geometry method is with the characteristic of easy construction and getting more accurate result, and this geometry method can help in advancing the accuracy of modeling and getting better result in application.

Study on Dynamic Survey of Group Geological Disasters in Dongjiang Reservoir Region, Zixing City, Using CBERS Images

XU Yueren,HE Honglin,SHEN Xuhui,CHEN Lize

2011, 47(4):  689-697. 

Asbtract ( )  

Related Articles | Metrics

The authors study on dynamic survey of the disasters happened in the Dongjiang reservoir Region, Zixing City, Hunan Province, using multi-period China-Brazil Earth Resource Satellite(CBERS) serial images for disaster interpretation. It shows the total landslides numbers are 105, 178, 66, 1344 and 153 in 1999, 2003, 2005, 2006 and 2008 respectively, and the total debris flows number is 13 in 2006. The research also shows that disasters mainly occurred by Bilis typhoon storm during July 14?16, 2006, with concentrated character and its density center was consistent with the storm center. Disasters’ image features can be indentified from surrounding surface features using newly images after the event, and the features may disappear gradually over time. The result shows that CBERS images can be used for monitoring the disasters’ changing process of happening-reduce-disappear over time in study area, and it can also be used for dynamic survey of geological disasters in China based on this effective case study.

Estimation of Forest Aboveground Biomass by Integrating GLAS and ETM Data

DONG Lixin,WU Bingfang,TANG Shihao

2011, 47(4):  703-710. 

Asbtract ( )  

Related Articles | Metrics

Based on the algorithm of forest canopy height for GLAS data, the neural net model of above ground biomass in complex terrain conditions was established. The map of forest aboveground biomass from BP neural net model was produced. Overall, forest canopy height and aboveground biomass have higher accuracy. The result of forest canopy height of needle-leaf forest has highest accuracy (R²=0.692). The result of broadleaf forest has higher accuracy (R²=0.5062). The results of forest aboveground biomass are very close to the fields measured results, and are consistent with land cover data in the spatial distribution.

Environmental Changes at the North of Jianghan Plain during Ming and Qing Period

ZHONG Yujia,MO Duowen,LI Yiyin,SHI Chenxi,HU Ke,LIU Hui

2011, 47(4):  711-718. 

Asbtract ( )  

Related Articles | Metrics

The Caidangxi profile is in the north of Jianghan Plain, Hubei Province, China. Synthetic analysis of grain size, chemical elements and pollen of sedimentary samples from Caidangxi profile reveal the paleo-environmental changes since 1250 AD of the area. The sediments of the profile dominantly consist of clay silts. The sedimentary characteristics, such as grain size and the sorting coefficient, together with the analysis geomorphic position on which the deposition occurred, may indicate that the sediments were deposited by sheet flood mainly from Han River in a slow hydrodynamic depositional process. The sedimentary characteristics also show some similarities with the loess sediments for that some materials were derived from the loess distributed in this river basin. The grain-size and sorting have a significantly increase in 1500 AD, which might reflect the effect of the intensified flooding process. The climatic history since 1250 AD could be identified four stages by geochemical elements and pollen analysis data. The climate of four stages were respectively “wet and warm”, “cool and dry”, “a little wet and warm” and “a little cool and dry”. The distinct cool and dry climate during around 1500 AD might reflect the response of an evidently lower temperature event of the Little Ice Age. It also might be one of the reasons for the intensified flood process during the same time.

Study of Freshman Adjustment after Enrollment: Empirical Research in Campus Using Newcomer Adjustment Model

LI Yixuan,CHEN Kun,YAO Xiang,WANG Yi

2011, 47(4):  719-726. 

Asbtract ( )  

Related Articles | Metrics

The present study investigated the relationship between the indicators of newcomer adjustment and the adjustment outcomes among college students. One hundred and forty-two Peking University freshmen enrolled in 2009 completed the adjustment indicators questionnaires and reported their general life satisfaction and depression 3 months after their enrollment. Six months after their enrollment, students were asked to report their recent psychological statement, and social activities and academic performance for the first semester. The results indicated that three key indicators of newcomer adjustment, that is, self-efficacy, social acceptance and role clarity could predict students’ general life satisfaction 3 and 6 months after their enrollment, depression 3 months after their enrollment and social activities, academic performance for the first semester. Specifically, self-efficacy contributed uniquely and significantly to general life satisfaction; social acceptance contributed uniquely and significantly to depression of 3 months and social activity performance; role clarity contributed uniquely and significantly to academic performance. These findings underlined the importance of the newcomer adjustment theory for freshman adjustment process of their campus life.

Ecological Risk Analysis for Shenzhen River Watershed Based on PESR Model

YANG Pei,LI Tianhong,MAO Xiaoling

2011, 47(4):  727-734. 

Asbtract ( )  

Related Articles | Metrics

In order to reveal the impact of rapid urbanization on watershed eco-environment, this paper establishes a pressure-effect-social response (PESR) model which is used to assess the regional ecological risk based on the pressure-state-response (PSR) framework model. The results show that, ERI of the watershed suffered some degree of reduction from 1993 to 2007, from level Ⅳ to level Ⅲ. PI increased continuously, and EI remained stable, while SRI decreased significantly with the strengthening of environmental protection measures. The assessment results show that despite the increasing pressure of society, the strengthening environmental protection measures could mitigate the risk dramatically.

Determination and Evaluation of Semivolatile Organic Pollutants in the Refinery Wastewater Sediment Using Ultrasonication Extraction Combined with GC/MS

WANG Yonghua,LI Liren,ZHANG Baozhong

2011, 47(4):  735-740. 

Asbtract ( )  

Related Articles | Metrics

The semivolatile organic pollutants in sediment of the refinery wastewater reservoir were determinated using ultrasonication extraction combined with GC/MS. The recovery of addition 16 polycyclic aromatic hydrocarbons (PAHs) as standard to soil was measured with range from 65%?94%. The 20 compounds from sediments were identified including 9 PAHs, 5 n-hydrocarbons and 3 phenols et al. Quantitative analysis was achieved with structure similitude as standard samples with range of the concentration of 0.1?259 ng/g. The log K_oc of naphthalene, fluorene and phenanthrene was estimated to be 3.82, 4.27 and 4.22, repectively. The antioxidant 3,5-di-tert-butyl-4-hydroxy-toluene was degraded to 3,5-di-tert-butyl-4-hydroxybenzaldehyde in the refinery wastewater and sediment.

Greenhouse Gas Emissions by Chinese Economy: An Assessment Based on EIO-LCA Model

JI Junping,LIU Lei,MA Xiaoming

2011, 47(4):  741-749. 

Asbtract ( )  

Related Articles | Metrics

The authors investigate greenhouse gas (GHG) emissions of the Chinese economy by producing sectors from production-based and consumption-based perspectives. A sectoral GHG emissions matrix is built based on Chinese Economic Input-Output Life Cycle Assessment (EIO-LCA) Model 2007 to incorporate the two perspectives in the same analysis framework. This matrix provides a better understanding of the relationship between GHG emissions from production and final demand. The results show that electric and heat power sector contributes the most direct emissions, 36.24% of total emissions, of which 93.91% are due to the production for other sectors, especially construction sector. Final demand for construction sector acounts for the highest embodied emissions, 29.79% of total emissions, of which 97.10% are emitted in other sectors of the supply chain, especially electric and heat power sector. Electric and heat power sector holds the top embodied emission intensity of 9.88 ton CO₂-eq/104 yuan, of which direct emission intensity contributes 89.70%.

Scale Sensitive Analysis of Cellular Automata Model

WANG Yang,GAO Yang,ZHAO Lin,ZHAO Zhiqiang,LI Shuangcheng

2011, 47(4):  750-758. 

Asbtract ( )  

Related Articles | Metrics

The authors present an analysis of how scale issues affect a cellular automata model of land use change developed for a research area in Longhua Town, Shenzhen City. The scale dependence of the model is explored by varying the resolution of the input data in 1990 used to calibrate the model and changing the length of model simulating time. To explore the impact of these scale relationships the model is run with input datasets constructed at the following spatial resolutions: 30, 60, 90, 120, 150, 180, 210 and 240 m for simulating land use in 1995 and 2000. Three kinds of indicator, i.e. point by point accuracy, Kappa and real change accuracy are used to assess the scale sensitivity of the model. The results show that 1) the more fine the cell sizes are, the higher the accuracy of the simulation results; 2) path dependence of the isolated cells is an important source of the spatial scale sensitivity of CA model; 3) the specific geographical process in different periods of time is an important source of the temporal sensitivity scale of CA model. The results have great significance for the scale selection of CA model.

Evaluating Income Impacts of Slopping Land Conversion Program in China: A Matching DID Model

XIE Xuxuan,MA Xunzhou,ZHANG Shiqiu

2011, 47(4):  759-767. 

Asbtract ( )  

Related Articles | Metrics

This paper is a theoretical and empirical study to compare different policy evaluation models. Using sloping land conversion program (SLCP) in China as an example, the authors apply a matching regression model, a DID model and a matching DID model to estimate policy impact on households’ incomes. The authors also explain the bias reduction from the approach of combining DID and matching strategies and proves the matching DID model a more efficient regression method. The matching DID is also useful to be adopted to evaluate policies in other fields.

Review of the Field Measurements and Parameterization of the Dust Emission Flux

ZHU Hao,ZHANG Hongsheng

2011, 47(4):  768-776. 

Asbtract ( )  

Related Articles | Metrics

Parameterization of dust emission flux is an important factor to accurately simulate and predict dust events. The data measured by field experiments can be used directly to evaluate the parameterization schemes. On the basis of explaining the physical mechanism, parameterization schemes and data inputs of various dust emission models, the authors investigate their similarities and differences. The field measurements of dust emission flux are critically needed for the validation, calibration and improvement of dust emission models. The gradient method and dust particle concentration measurements are two common methods to measure the dust emission flux during field experiments. The existing problems and future research directions are discussed by comparing the model parameterization schemes and results of field measurements.