检索结果-南通市图书馆

Study of statistically correcting model CMAQ-MOS for forecasting regional air quality

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第S2期48卷 155-172页

作者： XU Jianming, XU Xiangde, LIU Yu, DING Guoan, CHEN Huailiang, HU Jiangkai, ZHANG Jianchun, WU Hao, LI Weiliang, HE Jinhai, YANG Yuanqin & WANG Jiahe Nanjing University of Information Science & Technology, Nanjing 210044, china State Key Laboratory of Severe Weather, Chinese Academy of meteorological Sciences, beijing 100081, china meteorological Bureau of Henan Province, Institute of meteorological Sciences, Zhengzhou 450000, china national meteorological centre of china meteorological administration, beijing 100081, china national meteorological Information centre of china meteorological administration, beijing 100081, china Nanjing University of Information Science & Technology Nanjing 210044 China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China meteorological Bureau of Henan Province Institute of Meteorological Sciences Zhengzhou 450000 China national meteorological centre of china meteorological administration Beijing 100081 China national meteorological Information centre of china meteorological administration Beijing 100081 China

Based on analysis of the air pollution observational data at 8 observation sites in beijing including outer suburbs during the period from September 2004 to March 2005, this paper reveals synchronal and in-phase characteristics in the spatial and temporal variation of air pollutants on a city-proper scale at deferent sites; describes seasonal differences of the pollutant emission influence between the heating and non-heating periods, also significantly local differences of the pollutant emission influence between the urban district and outer suburbs, i.e. the spatial and temporal distribution of air pollutant is closely related with that of the pollutant emission intensity. This study shows that due to complexity of the spatial and temporal distribution of pollution emission sources, the new generation Community Multi-scale Air Quality (CMAQ) model developed by the EPA of USA produced forecasts, as other models did, with a systematic error of significantly lower than observations, albeit the model has better capability than previous models had in predicting the spatial distribution and variation tendency of multi-sort pollutants. The reason might be that the CMAQ adopts average amount of pollutant emission inventory, so that the model is difficult to objectively and finely describe the distribution and variation of pollution emission sources intensity on different spatial and temporal scales in the areas, in which the pollution is to be forecast. In order to correct the systematic prediction error resulting from the average pollutant emission inventory in CMAQ, this study proposes a new way of combining dynamics and statistics and establishes a statistically correcting model CMAQ-MOS for forecasts of regional air quality by utilizing the relationship of CMAQ outputs with corresponding observations, and tests the forecast capability. The investigation of experiments presents that CMAQ-MOS reduces the systematic errors of CMAQ because of the uncertainty of pollution e

关键词： CMAQ-MOS point-area combination emission source influence emission inventory air quality.

Relationship between the Asian-Pacific oscillation and the tropical cyclone frequency in the western North Pacific

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2008年第3期51卷 380-385页

作者： ZHOU BoTao1, CUI Xuan2 & ZHAO Ping3 1 Laboratory for Climate Studies, national Climate Center, china meteorological administration, beijing 100081, china 2 national meteorological Center, china meteorological administration, beijing 100081, china 3 Chinese Academy of meteorological Sciences, china meteorological administration, beijing 100081, china Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing China national meteorological Center China Meteorological Administration Beijing China Chinese Academy of meteorological Sciences China Meteorological Administration Beijing China

The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of ob- served data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale at- mospheric general circulation changes underlying the linkage between APO and the WNP tropical cy- clone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable envi- ronment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.

关键词： Asian-Pacific oscillation western North Pacific tropical cyclone atmospheric circulation

Predictor-based error correction method in short-term climate prediction

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第1期18卷 129-135页

作者： Hongli Ren Laboratory for Climate Studies,national Climate Center,china meteorological administration,beijing 100081,china Laboratory for Climate Studies National Climate Center China Meteorological Administration

In terms of the basic idea of combining dynamical and statistical methods in short-term climate prediction,a new prediction method of predictor-based error correction(PREC)is put forward in order to effectively use statistical experiences in dynamical ***- yses show that the PREC can reasonably utilize the significant correlations between predictors and model prediction errors and correct prediction errors by establishing statistical prediction ***,the PREC is further applied to the cross-validation experiments of dynamical seasonal prediction on the operational atmosphere-ocean coupled general circulation model of china meteorological Admin- istration/national Climate Center by selecting the sea surface temperature index in Ninflo3 region as the physical predictor that represents the prevailing ENSO-cycle mode of interannual variability in climate *** is shown from the prediction results of summer mean circulation and total precipitation that the PREC can improve predictive skills to some *** the PREC provides a new approach for improving short-term climate prediction.

关键词： Short-term climate prediction Seasonal prediction Predictor Error correction

Dense fog events in the Yangtze Delta and their climatic characteristics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第7期17卷 821-827页

作者： Zhou Zijiang~(**) Zhu Yanjun Ju Xiaohui (national meteorological Information centre,beijing 100081,china) national meteorological Information centre Beijing 100081 China

Based on daily observation records of fog and atmospheric visibility from 24 meteorological stations in the Yangtze Delta in the period from 1954 to 2005,the identification standard of dense fog events(DFE)has been proposed in this paper,a quite complete time series of DFEs for the delta constructed,and the climate characteristics of these events analyzed *** results showed that there were 564 typical DFEs in the delta from 1954 to *** most frequent season for DFEs was from October to next April,when the number of the events accounted for 89.9% of the annual total,while the least frequent season was summer,when the number only accounted for 1.6% of the total due to higher temperature and more convective weather in the *** the Yangtze Delta, DFEs occurred less and were weaker in the 1960s,but turned to increase from the end of the 1970s to the beginning of the 1980s,with an abrupt change in ***,DFEs occurred more frequently,intensively,and indeterministically,and in particular,most fre- quently in the 1980s and intensively in the *** both the frequency and intensity of DFEs decline apparently in the period of 2000—2005 in the delta.

关键词： the Yangtze Delta dense fog events(DFE) inter-annual variation Mann-Kendall method running-t test

Sea surface temperature east of Australia:A predictor of tropical cyclone frequency over the western North Pacific?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第2期56卷 196-201页

作者： ZHOU BoTao 1,2 & CUI Xuan 3 1 national Climate Center,china meteorological administration,beijing 100081,china 2 Nansen-Zhu International Research Center,Institute of Atmospheric Physics,Chinese Academy of Sciences,beijing 100029,china 3 national meteorological Center,china meteorological administration,beijing 100081,china national Climate Center China Meteorological Administration Beijing China Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China national meteorological Center China Meteorological Administration Beijing China

The relationship between sea surface temperature (SST) east of Australia and tropical cyclone frequency over the western North Pacific (WNPTCF) is analyzed by use of observation *** WNPTCF from June to October is correlated negatively to spring SST east of *** the spring SST is in the positive phase,a cyclonic circulation anomaly in the upper troposphere and an anticyclonic circulation anomaly in the lower troposphere prevail over the western North Pacific from June to October,concurrent with an anomalous atmospheric subsidence and an enlarged vertical zonal wind *** conditions are unfavorable for tropical cyclone genesis,and thus WNPTCF *** negative phase of the spring SST east of Australia leads to more tropical cyclones over the western North *** spring SST east of Australia may give rise to simultaneous change in tropical atmospheric circulation via the teleconnection wave train,and then subsequently affect atmospheric circulation variation over the western North Pacific.

关键词：热带气旋北太平洋澳大利亚西部海面温度热带大气环流预测频率

Principle and application of three-band gradient difference vegetation index

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第2期48卷 241-249页

作者： TANG Shihao, ZHU Qijiang, WANG Jindi, ZHOU Yuyu & ZHAO Feng Research Center for Remote Sensing and GIS, Department of Geography, beijing Normal University, beijing 100875, china national Satellite meteorological Center, china meteorological administration, beijing 100081, china Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing China national Satellite meteorological Center China Meteorological Administration Beijing China

Vegetation index is a simple, effective and experiential measurement of terrestrial vegetation activity, and plays a very important role in qualitative and quantitative remote sensing. Aiming at shortages of current vegetation indices, and starting from the analysis of vegetation spectral characteristics, we put forward a new vegetation index, the three-band gradient difference vegetation index (TGDVI), and established algorithms to inverse crown cover fraction and leaf area index (LAI) from it. Theoretical analysis and model simulation show that TGDVI has high saturation point and the ability to remove the influence of background to some degree, and the explicit functional relation with crown cover fraction and LAI can be established. Moreover, study shows that TGDVI also has the ability to partly remove the influence of thin cloud. Experiment in the Shunyi District, beijing, china shows that reasonable result can be reached using the vegetation index to retrieve LAI. We also theoretically analyzed the reason why the normalized difference vegetation index (NDVI) owns the low saturation point, and show that it is determined by the definition of NDVI and the characteristic of vegetation spectra, and is unavoidable to some degree. Meanwhile, through model simulation, we also indicate that the relationship between simple ratio vegetation index (SR) and LAI closes to a piecewise linear one instead of a linear one, which is mainly caused by the influence of background and different change rates of reflectance in red and infrared bands with LAI increasing.

关键词： vegetation index, remote sensing, LAI, crown cover fraction, remote sensing inversion.

A comparative analysis on two solar proton events

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第1期52卷 47-51页

作者： LE GuiMing1,2,3,4, HAN YanBen2 & ZHANG YiJun3 1 Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, china meteorological administration, beijing 100081, china 2 national Astronomical Observatories, Chinese Academy of Sciences, beijing 100012, china 3 Chinese Academy of meteorological Sciences, china meteorological administration, beijing 100081, china 4 national Center for Space Weather, china meteorological administration, beijing 100081, china Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration Beijing 100081 China

This paper presents a comparative analysis on the two Solar Proton Events (SPE), which occurred on 14 July 2000 (Bastille Day) and 28 October 2003 (28OCT03) respectively. It is found that although the peak flux of the latter seemed to be greater than that of the former based on geostationary observations, the maximum intensities of the energetic protons (>10 MeV and 30 MeV) during the Bastille Day event were all higher than those of the 28OCT03 event according to the interplanetary observations. Further analysis indicated that the quantity of the seed particles, which could be accelerated to the energies exceeding 10 and 30 MeV by the Coronal Mass Ejection (CME)-driven shock on 14 July 2000, was far larger than that of the 28OCT03 event. In the Bastille Day case, when the CME approached to the height around 14 R⊙, the CME-driven shock would reach its maximum capacity in accelerating the solar en- ergetic protons (>100 MeV). In contrast, on 28 October 2003, when CME approached to the height about 58R⊙, the CME-driven shock reached its highest potential in accelerating the solar energetic protons of the same category. At this moment, the peak flux (>100 MeV) was about 155 pfu, which was much lower than 355 pfu measured on 14 July 2000. This demonstrated that in the Bastille Day event, the quantity of the seed particles, which could be accelerated to the energy beyond 100 MeV, was significantly larger than its counterpart in the 28OCT03 case. Therefore, the peak flux of an SPE event depends not only on the interplanetary intensity of the solar energetic particles, but also on the velocity of the associated CME-driven shock, and the quantity of the seed particles as well as on the interplanetary magnetic en- vironment. This paper also reveals that the magnetic sheath associated with ICME on 28 October 2003 captured a large number of solar energetic protons, including those having energy greater than 100 MeV.

关键词：太阳质子 CME 太阳耀斑太阳系

Simulation of 1991-2005 Meiyu seasons in the Yangtze-Huaihe region using BCC_RegCM 1.0

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2010年第11期55卷 1077-1083页

作者： HU YaMin1,2,3& DING YiHui4 1 Institute of Tropical and Marine Meteorology, china meteorological administration, Guangzhou 510080, china 2 Guangdong Climate Center, Guangzhou 510080, china 3 Chinese Academy of meteorological Sciences, beijing 100081, china 4 national Climate Center, china meteorological administration, beijing 100081, china Institute of Tropical and Marine Meteorology China Meteorological Administration Guangzhou 510080 China Guangdong Climate Center Guangzhou 510080 China Chinese Academy of meteorological Sciences Beijing 100081 China national Climate Center China Meteorological Administration Beijing 100081 China

By using BCC_RegCM 1.0 (RegCM for short) from beijing Climate Center (BCC), china meteorological administration (CMA), the Meiyu season characters over the Yangtze-Huaihe region during 1991-2005 are simulated. The major conclusions of this study may be summarized as the following: (1) RegCM can reproduce the interannual variation and the spatial distribution of the summertime precipitation and temperature in the Yangtze-Huaihe region. (2) By use of a generalized Meiyu criterion and in accordance with model-calculated precipitation and temperature, the Meiyu onset and ending date have been determined. Compared with the observation, RegCM can simulate the interannual variation of the Yangtze-Huaihe Meiyu with preferable capability for most of the normal Meiyu years (such as 1995, 1997, 2000, 2001, 2002 and 2004), especially for the rich Meiyu years of 1996, 1998 and 1999. (3) In terms of the average simulation for the recent 15 years, the timings of onset and ending of Meiyu occur on June 1 and July 13, respectively, which are earlier than the climatological observation. For duration, Meiyu persists for 32 d, 3 d shorter than the observation. The index of Meiyu intensity is 2.45, while the climatological one is 3.00. Therefore, RegCM is capable of simulating the climatological Meiyu duration and intensity, while the capability of simulating the onset and ending date of Meiyu still needs to be improved.

关键词：梅雨季节模拟计算长江气候观测发病时间强度指数中国气象局空间分布

Multitime scale variations of sea surface temperature in the china seas based on the HadISST dataset

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2011年第4期30卷 14-23页

作者： JIN Qihua WANG Hui Chinese Academy of meteorological Sciences China Meteorological Administration Beijing 100081 China national Marine Environmental Forecasting Center State Oceanic Administration Beijing 100081 China

The variability of the sea surface temperature（SST） in the china seas has been studied in seasonal,interannual and interdecadal scales based on the monthly data of HadISST spanning from 1870 to 2007. The main results obtained are SST in the china offshore changes most actively at the seasonal scale with the intensity diminishing from north to south,as the temperature differences between summer and winter reaching 17 and 4 C in the northern and southern areas,respectively. Moreover,seasonal variation near the coastal regions seems relatively stronger than that far from the coastline;significant interannual variations are detected,with the largest positive anomaly occurring in 1998 in the overall area. But as far as different domains are concerned,there exists great diversity,and the difference is also found between winter and summer. Differed from the seasonal variations,where the strongest interannual variability takes place,resides to the south of that of the seasonal ones in the northern section,nevertheless in the South china Sea,the most significant interannual variability is found in the deep basin;interdecadal changes of summer,winter and annual mean SST in different domains likewise present various features. In addition,a common dominant warming in recent 20 a are found in the overall china offshore with the strongest center located in the vicinity of the Changjiang Estuary in the East china Sea,which intensifies as high as 1.3 C during the past 130 a.

关键词： china seas sea surface temperature multitime scale variations