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基于GRAPES全球分析系统的Hybrid-3DVAR混合同化研究
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作者 张利红 龚建东 庄照荣 《高原山地气象研究》 2024年第1期41-50,共10页
本文基于我国自主研发的GRAPES全球3DVAR同化系统,利用NCEP全球集合预报产品和time-lagged方法,针对膨胀系数、集合样本数和集合权重系数,开展了每日4次、连续一周的GRAPES全球Hybrid-3DVAR混合同化研究。结果表明:所有试验中,集合样本... 本文基于我国自主研发的GRAPES全球3DVAR同化系统,利用NCEP全球集合预报产品和time-lagged方法,针对膨胀系数、集合样本数和集合权重系数,开展了每日4次、连续一周的GRAPES全球Hybrid-3DVAR混合同化研究。结果表明:所有试验中,集合样本取60个、集合权重取0.5时,得到的混合同化分析和预报误差最小;在该混合同化系统中,在高层也考虑静态背景误差协方差和集合背景误差协方差的耦合,可避免混合同化方案分析场误差在150 hPa及以上过大,并超过3DVAR分析场误差的情况。 展开更多
关键词 混合同化 grapes全球3DVAR 背景误差协方差
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New Opportunities for the Development of Regional Architectural Culture in the Process of Globalization 被引量:1
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作者 徐姝 沈一 曾令强 《Journal of Landscape Research》 2011年第1期28-30,共3页
Combining with the new understanding of "globalization" and "regionality",increasingly prominent conflicts between the two are elaborated,right attitude towards the conflicts and fundamental soluti... Combining with the new understanding of "globalization" and "regionality",increasingly prominent conflicts between the two are elaborated,right attitude towards the conflicts and fundamental solutions are proposed to settle the conflicts,so as to clarify new opportunities for the development of regional architectural culture in the process of globalization. 展开更多
关键词 globalIZATION regionality ARCHITECTURE CULTURE
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Historical Evolution of Global and Regional Surface Air Temperature Simulated by FGOALS-s2 and FGOALS-g2: How Reliable Are the Model Results? 被引量:18
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作者 周天军 宋丰飞 陈晓龙 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第3期638-657,共20页
In order to assess the performance of two versions of the IAP/LASG Flexible Global Ocean-Atmosphere- Land System (FGOALS) model, simulated changes in surface air temperature (SAT), from natural and an- thropogenie... In order to assess the performance of two versions of the IAP/LASG Flexible Global Ocean-Atmosphere- Land System (FGOALS) model, simulated changes in surface air temperature (SAT), from natural and an- thropogenie forcings, were compared to observations for the period 1850-2005 at global, hemispheric, conti- nental and regional scales. The global and hemispheric averages of SAT and their land and ocean components during 1850-2005 were well reproduced by FGOALS-g2, as evidenced by significant correlation coefficients and small RMSEs. The significant positive correlations were firstly determined by the warming trends, and secondly by interdecadal fluctuations. The abilities of the models to reproduce interdecadal SAT variations were demonstrated by both wavelet analysis and significant positive correlations for detrended data. The observed land-sea thermal contrast change was poorly simulated. The major weakness of FGOALS-s2 was an exaggerated warming response to anthropogenic forcing, with the simulation showing results that were far removed from observations prior to the 1950s. The observations featured warming trends (1906-2005) of 0.71, 0.68 and 0.79℃ (100 yr)-1 for global, Northern and Southern Hemispheric averages, which were overestimated by FGOALS-s2 [1.42, 1.52 and 1.13~C (100 yr)-1] but underestimated by FGOALS-g2 [0.69, 0.68 and 0.73~C (100 yr)-l]. The polar amplification of the warming trend was exaggerated in FGOALS- s2 but weakly reproduced in FGOALS-g2. The stronger response of FGOALS-s2 to anthropogenic forcing was caused by strong sea-ice albedo feedback and water vapor feedback. Examination of model results in 15 selected subcontinental-scale regions showed reasonable performance for FGOALS-g2 over most regions. However, the observed warming trends were overestimated by FGOALS-s2 in most regions. Over East Asia, the meridional gradient of the warming trend simulated by FGOALS-s2 (FGOALS-g2) was stronger (weaker) than observed. 展开更多
关键词 FGOALS 20th century historical simulation warming trends global scale hemispheric scale regional scale
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Possible Sources of Forecast Errors Generated by the Global/Regional Assimilation and Prediction System for Landfalling Tropical Cyclones.PartⅠ:Initial Uncertainties 被引量:4
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作者 Feifan ZHOU Munehiko YAMAGUCHI Xiaohao QIN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第7期841-851,共11页
This paper investigates the possible sources of errors associated with tropical cyclone (TC) tracks forecasted using the Global/Regional Assimilation and Prediction System (GRAPES). The GRAPES forecasts were made ... This paper investigates the possible sources of errors associated with tropical cyclone (TC) tracks forecasted using the Global/Regional Assimilation and Prediction System (GRAPES). The GRAPES forecasts were made for 16 landfaIling TCs in the western North Pacific basin during the 2008 and 2009 seasons, with a forecast length of 72 hours, and using the default initial conditions ("initials", hereafter), which are from the NCEP-FNL dataset, as well as ECMWF initials. The forecasts are compared with ECMWF forecasts. The results show that in most TCs, the GRAPES forecasts are improved when using the ECMWF initials compared with the default initials. Compared with the ECMWF initials, the default initials produce lower intensity TCs and a lower intensity subtropical high, but a higher intensity South Asia high and monsoon trough, as well as a higher temperature but lower specific humidity at the TC center. Replacement of the geopotential height and wind fields with the ECMWF initials in and around the TC center at the initial time was found to be the most efficient way to improve the forecasts. In addition, TCs that showed the greatest improvement in forecast accuracy usually had the largest initial uncertainties in TC intensity and were usually in the intensifying phase. The results demonstrate the importance of the initial intensity for TC track forecasts made using GRAPES, and indicate the model is better in describing the intensifying phase than the decaying phase of TCs. Finally, the limit of the improvement indicates that the model error associated with GRAPES forecasts may be the main cause of poor forecasts of landfalling TCs. Thus, further examinations of the model errors are required. 展开更多
关键词 tropical cyclone track forecast error diagnosis global/regional Assimilation and Prediction System initialuncertainty
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Bioactive compounds of red grapes from Dao region(Portugal):Evaluation of phenolic and organic profile 被引量:1
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作者 Luís Rodrigues Silva Mafalda Queiroz 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2016年第4期315-321,共7页
Objective:To improve the knowledge on the metabolite profile of five red grapes from D?o region(Portugal),concerning to the phenolic characteristics(coloured and non-coloured phenolics) and organic acid composition.Me... Objective:To improve the knowledge on the metabolite profile of five red grapes from D?o region(Portugal),concerning to the phenolic characteristics(coloured and non-coloured phenolics) and organic acid composition.Methods:Five red grapes collected from D?o region were studied.The profiles of phenolic compounds and organic acids were estimated by high-performance liquid chromatography with diode-array detection and high-performance liquid chromatography with UV detector,respectively.Results:Totally 24 phenolic compounds were identified,and distributed by several classes:8 anthocyanins,1 hydroxybenzoic acid,4 hydroxycinnamic acids,1 stilbene,4flavan-3-ols,6 flavonols.Additionally,10 organic acids were detected in all samples.Total contents of each phenolic class and organic acids amounts varied significantly among the different grape cultivars investigated.The principal components analysis differentiates the Touriga Nacional from the other varieties due to their high contents in anthocyanins,non-coloured phenolics and organic acids.Touriga Nacional is an important red grape cultivar,highly esteemed in D?o region for its ability to produce high quality wines.Conclusions:The results suggest that the red grapes from D?o region present a good composition in bioactive compounds,being important for the production of wines with superior quality. 展开更多
关键词 Vitis vinifera grapes Dao region Phenolics Organic acids
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Projected Regional 1.50℃and 2.00℃Warming Threshold-crossing Time Worldwide Using the CMIP6 Models
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作者 MENG Yali DUAN Keqin +5 位作者 SHANG Wei SHI Peihong LI Shuangshuang CHENG Ying CHEN Rong ZHANG Zhaopeng 《Chinese Geographical Science》 SCIE CSCD 2023年第6期1095-1108,共14页
The Paris Agreement aims to limit global warming to well below 2.00℃and pursue efforts to limit the temperature increase to 1.50℃.However,the response of climate change to unbalanced global warming is affected by sp... The Paris Agreement aims to limit global warming to well below 2.00℃and pursue efforts to limit the temperature increase to 1.50℃.However,the response of climate change to unbalanced global warming is affected by spatial and temporal sensitivities.To better understand the regional warming response to global warming at 1.50℃and 2.00℃,we detected the 1.50℃and 2.00℃warming threshold-crossing time(WTT)above pre-industrial levels globally using the Coupled Model Intercomparison Project phase 6(CMIP6)models.Our findings indicate that the 1.50℃or 2.00℃WTT differs substantially worldwide.The warming rate of land would be approximately 1.35–1.46 times that of the ocean between 60°N–60°S in 2015–2100.Consequently,the land would experience a 1.50℃(2.00℃)warming at least 10–20 yr earlier than the time when the global mean near-surface air temperature reaches 1.50℃(2.00℃)WTT.Meanwhile,the Southern Ocean between 0°and 60°S considerably slows down the global 1.50℃and 2.00℃WTT.In 2040–2060,over 98.70%(77.50%),99.70%(89.30%),99.80%(93.40%),and 100.00%(98.00%)of the land will have warmed by over 1.50℃(2.00℃)under SSP(Shared Socioeconomic Pathway)1–2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5,respectively.We conclude that regional 1.50℃(2.00℃)WTT should be fully considered,especially in vulnerable high-latitude and high-altitude regions. 展开更多
关键词 CMIP6(Coupled Model Intercomparison Project phase 6) global warming 1.50℃warming time 2.00℃warming time regional differences
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The comparative African regional economics of globalization in financial allocation efficiency: the pre-crisis era revisited
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作者 Simplice A.Asongu Joseph Nnanna Vanessa S.Tchamyou 《Financial Innovation》 2020年第1期1-41,共41页
This study assesses the role of globalization-fueled regionalization policies on the financial allocation efficiency of four economic and monetary regions in Africa from 1980 to 2008.Banking and financial system effic... This study assesses the role of globalization-fueled regionalization policies on the financial allocation efficiency of four economic and monetary regions in Africa from 1980 to 2008.Banking and financial system efficiency proxies are used as dependent variables and seven bundled and unbundled globalization variables are employed as independent indicators.The bundling is achieved by principal component analysis,while the empirical evidence is based on interactive fixed effects regressions.The findings are as follows.First,financial allocation efficiency is more sensitive to financial openness compared to trade openness and most sensitive to globalization.The relationship between allocation efficiency and globalization-fueled regionalization policies is defined by:(i)a Kuznets or inverted U-shaped curve in the UEMOA and CEMAC zones(evidence of decreasing returns for allocation efficiency from globalization-fueled regionalization)and(ii)a U-shaped relationship overwhelmingly in the COMESA and scantily in the EAC(increasing returns to allocation efficiency due to globalization-fueled regionalization).These relationships are relevant to the specific globalization dynamics within regions.Economic and monetary regions are more prone to surplus liquidity than pure economic regions are.Policy implications and measures for reducing surplus liquidity are also discussed. 展开更多
关键词 globalIZATION Financial development regional integration Panel AFRICA
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Constructing a New Polish Architecture: Critical Regionalism and Resistance to Globalization after 1989
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作者 Krystyna Januszkiewicz 《Journal of Civil Engineering and Architecture》 2014年第12期1518-1526,共9页
This paper explores the critical regionalism which could play a role in the continued development of global era Polish architecture, and the advancements achieved by those few contemporary Polish architects who have s... This paper explores the critical regionalism which could play a role in the continued development of global era Polish architecture, and the advancements achieved by those few contemporary Polish architects who have sought to combine modern tastes and techniques with culturally meaningful designs. The new culture of Poland is very much reflected in the design of many of its new buildings that have been completed since the political and economic changes in 1989. The architecture of Poland appears to have lurched from an inappropriate socialist modernism that was so horridly imposed during the communist era to an equally inappropriate post modernist hegemony in the new enterprise culture. In accordance with Poland, now is rejection of the centrally imposed system of building and architecture, and with the greater emphasis on individual initiative in the new culture, it seems a pity that the country should automatically adopt western modes of architectural expression. This paper suggests that with its newly founded freedom, Poland should be careful that it does not suffer a loss of identity and that, in its architecture, it should seek a way forward through a critical regionalism. 展开更多
关键词 ARCHITECTURE CULTURE critical regionalism globalIZATION RESISTANCE Poland.
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Unveiling Global Human Trafficking Trends: A Comprehensive Analysis
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作者 Somtobe Olisah Clement Odooh +5 位作者 Oghenekome Efijemue Echezona Obunadike Jane Onwuchekwa Omoshola Owolabi Saheed Akintayo Callistus Obunadike 《Journal of Data Analysis and Information Processing》 2024年第1期49-75,共27页
This paper presents a comprehensive analysis of global human trafficking trends over a twenty-year period, leveraging a robust dataset from the Counter Trafficking Data Collaborative (CTDC). The study unfolds in a sys... This paper presents a comprehensive analysis of global human trafficking trends over a twenty-year period, leveraging a robust dataset from the Counter Trafficking Data Collaborative (CTDC). The study unfolds in a systematic manner, beginning with a detailed data collection phase, where ethical and legal standards for data usage and privacy are strictly observed. Following collection, the data undergoes a rigorous preprocessing stage, involving cleaning, integration, transformation, and normalization to ensure accuracy and consistency for analysis. The analytical phase employs time-series analysis to delineate historical trends and utilizes predictive modeling to forecast future trajectories of human trafficking using the advanced analytical capabilities of Power BI. A comparative analysis across regions—Africa, the Americas, Asia, and Europe—is conducted to identify and visualize the distribution of human trafficking, dissecting the data by victim demographics, types of exploitation, and duration of victimization. The findings of this study not only offer a descriptive and predictive outlook on trafficking patterns but also provide insights into the regional nuances that influence these trends. The article underscores the prevalence and persistence of human trafficking, identifies factors contributing to its evolution, and discusses the implications for policy and law enforcement. By integrating a methodological approach with quantitative analysis, this research contributes to the strategic planning and resource allocation for combating human trafficking. It highlights the necessity for continued research and international cooperation to effectively address and mitigate this global issue. The implications of this research are significant, offering actionable insights for policymakers, law enforcement, and advocates in the ongoing battle against human trafficking. 展开更多
关键词 Human Trafficking global Trends Data Analysis Victim Demographics Policy Implications Technological Advancements Socioeconomic Factors Forecasting regional Disparities Transnational Crime
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Regional VS. Global Patterns of Democratization: A Comparative Study
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作者 Kunihiko Imai 《International Relations and Diplomacy》 2014年第3期176-198,共23页
This study analyzes the comparative patterns of democratization between geographic regions and the world. It addresses the question that how some determinants of democracy have different effects among geographical reg... This study analyzes the comparative patterns of democratization between geographic regions and the world. It addresses the question that how some determinants of democracy have different effects among geographical regions. Further, by comparing the similarities and differences in the patterns of democratic diffusion across regions, this study seeks to delineate what changes scholars should adopt in our epistemological approaches and methodological tools, such as the indices of democracy, in an attempt to better understand the policy implications of disparate findings from various empirical studies. As part of a larger research project, this paper focuses its attention on two of the geographical regions Asia and the Middle East. 展开更多
关键词 DEMOCRATIZATION determinants of democracy levels of democracy regional vs. global democratization.
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Dancing Ping-Pong Promotes Global Collaboration——At the Sports Economy and International Regional Cooperation Forum for the Belt and Road Initiative in 2018
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作者 Li Houqiang Chen Youbin 《Contemporary Social Sciences》 2018年第5期1-8,共8页
Sichuan is the strongest province in western China, and Chengdu is the first stop of the Silk Road and the Yangtze River Economic Zone. Qingbaijiang,the inception point of the Chengdu-Europe express railway, is an imp... Sichuan is the strongest province in western China, and Chengdu is the first stop of the Silk Road and the Yangtze River Economic Zone. Qingbaijiang,the inception point of the Chengdu-Europe express railway, is an important source of artifacts from the ancient Sichuan civilization, and Sichuan province, the land of abundance, is the cradle and base of ping-pong. Chengdu has been connected to 展开更多
关键词 In At the Sports Economy and International regional Cooperation Forum for the Belt and Road Initiative in 2018 Dancing Ping-Pong Promotes global Collaboration
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热带风压场平衡特征及其对GRAPES系统中同化预报的影响研究Ⅱ:动力与统计混合平衡约束方案的应用 被引量:10
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作者 王瑞春 龚建东 +1 位作者 张林 陆慧娟 《大气科学》 CSCD 北大核心 2015年第6期1225-1236,共12页
研究I的结果表明:线性平衡方程(LBE)在热带地区不适用,而进一步改进方向是削弱LBE在该区域的约束程度。本文以此为基础,在GRAPES(global/regional assimilation and prediction system)全球变分同化系统中引入动力与统计混合平衡约束方... 研究I的结果表明:线性平衡方程(LBE)在热带地区不适用,而进一步改进方向是削弱LBE在该区域的约束程度。本文以此为基础,在GRAPES(global/regional assimilation and prediction system)全球变分同化系统中引入动力与统计混合平衡约束方案。新方案在逐层求解LBE的基础上增加垂直方向的线性回归,回归系数随纬度和高度变化。针对背景误差协方差的分析表明,新方案可以更好的保证独立分析变量间预报误差不相关的基本要求,并大幅度减小热带地区平衡气压预报误差方差的量值和占总方差的比例。单点试验结果表明,与LBE方案相比,新方案对中、高纬影响很小,但在热带地区成功实现了风、压场分析的解耦,两者分析更为独立。并且,虽未考虑具体波动模态,但新方案给出的风、压场协相关结构与研究I的理论分析结果相近。一个月的同化循环与预报结果表明,引入新方案后,赤道外地区的同化预报效果为中性偏正,而热带地区风场的同化预报效果显著提高,LBE方案中平流层低层的风场同化预报异常被基本消除。 展开更多
关键词 变分资料同化 平衡约束 线性平衡方程 线性回归 grapes(global/regional ASSIMILATION and prediction system)
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GRAPES全球三维变分同化系统——基本设计方案与理想试验 被引量:65
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作者 庄世宇 薛纪善 +2 位作者 朱国富 赵军 朱宗申 《大气科学》 CSCD 北大核心 2005年第6期872-884,共13页
中国气象局数值预报研究中心开发了一个全球和区域统一框架的格点三维变分资料同化系统(GRAPES3D-Var)。作者给出全球版本的方案设计,采用单点观测试验检验方案设计的合理性和正确性。全球方案选择流函数、速度势、非平衡高度和相对湿... 中国气象局数值预报研究中心开发了一个全球和区域统一框架的格点三维变分资料同化系统(GRAPES3D-Var)。作者给出全球版本的方案设计,采用单点观测试验检验方案设计的合理性和正确性。全球方案选择流函数、速度势、非平衡高度和相对湿度作为分析求解的控制变量,用线性平衡方程作为质量场和风场的动力约束,通过预调方法解决背景误差协方差矩阵阶数过大和难以求逆的问题,其中垂直变换和物理变换以及观测算子设计等方面与区域方案相同,但预调的水平变换采用球谐函数谱滤波表示背景误差协方差的水平相关模型,避免了递归滤波在高纬和极区因相关尺度过大无法实施的问题。另外,设计了一个使极区插值和差分计算完全闭合的网格以及相应的算法,解决了极点分析问题。单点观测理想试验结果表明,GRAPES 3D-Var系统能够合理给出全球任何地区的分析。 展开更多
关键词 全球/区域同化预报系统 全球三维变分资料同化系统 谱滤波 理想试验
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Antisepsis and Fresh-keeping Effects of Natamycin Coating Compounds Treatment on Red Global Grape 被引量:3
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作者 周会玲 刘美迎 +2 位作者 任小林 吴主莲 张维 《Agricultural Science & Technology》 CAS 2012年第9期2012-2016,2036,共6页
The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions... The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions at 0.20% (T1), 0.40% (T2) and 0.60% (T3), respectively. Grapes processed with water (CK3) and 1% chitosan (CK2) were taken as control groups. Rotten rate, seed shattering rate, mass loss rate, respiratory intensity and related physiological quality in test and control groups were compared. The results indicated that respiratory intensity, mass loss rate, rotten rate and seed shattering rate in CK1 were all higher than those in CK2. In addition, T1, T2 and T3 were lower in the indices than CK1 and CK2, but still kept at a high level in fruit hardness. Furthermore, mass fractions of Vc and titratable acid declined more slowly in T1, T2 and T3, compared with CK1 and CK2. Natamycin better preserved grapes and prolonged storage period. In general, natamycin with mass fraction at 0.4% proved best in fresh-keeping. 展开更多
关键词 NATAMYCIN CHITOSAN Red global grape ANTISEPSIS Fresh-keeping
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FY-2E云导风的算法改进及其在GRAPES中的同化应用研究 被引量:14
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作者 万晓敏 田伟红 +3 位作者 韩威 王瑞文 张其松 张晓虎 《气象》 CSCD 北大核心 2017年第1期1-10,共10页
2014年国家卫星气象中心全面改进了风云二号卫星云导风产品算法,为评估算法改进后FY-2E云导风资料对我国GRAPES数值模式同化和预报的影响,根据国家卫星气象中心提供的2013年8月算法改进前后的FY-2E红外通道云导风资料,对比分析了两者的... 2014年国家卫星气象中心全面改进了风云二号卫星云导风产品算法,为评估算法改进后FY-2E云导风资料对我国GRAPES数值模式同化和预报的影响,根据国家卫星气象中心提供的2013年8月算法改进前后的FY-2E红外通道云导风资料,对比分析了两者的观测分布及偏差特征,并利用GRAPES全球模式进行了一个月的连续试验。结果表明,改进算法后的FY-2E红外通道云导风观测数量明显增加,观测误差在600~200 hPa有所减小,风的平均偏差在高层减少,更满足正态分布;连续试验结果表明北半球和东亚地区风场在300~150 hPa分析中改进显著,风的平均偏差和均方根误差明显减少;预报结果显示500 hPa高度场预报距平相关系数略提高,均方根误差略减小;说明改进算法后的FY-2E红外通道云导风对GRAPES数值模式同化和预报均有一定改善。 展开更多
关键词 FY-2E红外云导风资料 grapes数值模式 资料同化 影响试验
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Global-Region:全球化背景下的城市区域现象 被引量:17
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作者 李红卫 吴志强 +1 位作者 易晓峰 彭涛 《城市规划》 CSSCI 北大核心 2006年第8期31-37,共7页
全球化日益促成了城市区域新的演变,一方面世界城市、全球城市出现了,另一方面出现世界城市的区域日益成为世界关注的对象。与此同时,学术界对全球化下的城市区域现象进行了大量研究,主要是对当前城市区域现象进行的总结,而对未来城市... 全球化日益促成了城市区域新的演变,一方面世界城市、全球城市出现了,另一方面出现世界城市的区域日益成为世界关注的对象。与此同时,学术界对全球化下的城市区域现象进行了大量研究,主要是对当前城市区域现象进行的总结,而对未来城市区域现象的研究较少。本文提出Global-Region的概念,认为Global-Region应成为未来城市与区域发展的方向,并对世界上的Global-Region进行实证分析,对我国的珠江三角洲发展进行了展望。 展开更多
关键词 global-region 全球化 珠江三角洲
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GRAPES全球变分同化背景误差协方差的改进及对分析预报的影响:背景误差协方差三维结构的估计 被引量:24
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作者 王金成 庄照荣 +1 位作者 韩威 陆慧娟 《气象学报》 CAS CSCD 北大核心 2014年第1期62-78,共17页
回顾并详细推导了估计背景误差协方差统计特征的美国国家气象中心(NMC)方法及其优缺点;采用NMC方法系统地估计了新版GRAPES全球模式的背景误差方差、水平相关特征尺度和垂直相关结构,并与欧洲中心模式结果进行了比较。结果表明,目前GRA... 回顾并详细推导了估计背景误差协方差统计特征的美国国家气象中心(NMC)方法及其优缺点;采用NMC方法系统地估计了新版GRAPES全球模式的背景误差方差、水平相关特征尺度和垂直相关结构,并与欧洲中心模式结果进行了比较。结果表明,目前GRAPES全球模式的背景误差方差比以前有了显著减小;水平相关特征尺度随纬度和高度有显著变化;背景误差垂直相关结构与欧洲中心模式结果非常一致,相比经验公式结果更具物理意义,同时,单点试验结果也表明,更新后的垂直相关结构产生的分析增量更合理。通过与欧洲中心模式背景误差协方差三维结构的对比,分析了不同模式间背景误差协方差的异同及GRAPES全球同化分析系统目前存在的一些不足及可能原因。为新版GRAPES全球模式的三维变分系统提供了基本的背景误差协方差的三维结构。 展开更多
关键词 背景误差协方差 美国国家气象中心(NMC)方法 grapes全球模式 变分同化
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PRM标量平流方案在GRAPES全球预报系统中的应用 被引量:11
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作者 苏勇 沈学顺 +4 位作者 彭新东 李兴良 伍湘君 张爽 陈贤 《大气科学》 CSCD 北大核心 2013年第6期1309-1325,共17页
如何更好地模拟水物质的分布,对于数值天气预报效果的改进,特别是对于更好地模拟降水过程,具有重要的意义。半拉格朗日模式中的标量平流计算要求做到高精度、守恒、正定和保形,但GRAPES_GFS(Global-Regional Assimilation and PrEdictio... 如何更好地模拟水物质的分布,对于数值天气预报效果的改进,特别是对于更好地模拟降水过程,具有重要的意义。半拉格朗日模式中的标量平流计算要求做到高精度、守恒、正定和保形,但GRAPES_GFS(Global-Regional Assimilation and PrEdiction System,Global Forecast System)中采用的QMSL(Quasi-Monotone Semi-Lagrangian)平流方案在水汽的强梯度、不连续区域计算精度较低,且不能做到严格守恒。本研究借鉴计算流体力学领域的研究进展,将一个基于分段有理函数的物质平流方案PRM(Piecewise Rational Method)引入GRAPES_GFS中,按照通量形式求解水汽方程,并对极区进行了混合等技术处理。通过一系列理想试验对两种平流方案进行了对比,证明了PRM方案精度较高,特别是在水汽梯度大的区域优势明显,频散、耗散误差较小,守恒、保形性也要好于QMSL方案。通过对GRAPES_GFS中批量预报试验效果的检验,验证了PRM方案可以有效地改进模式对水物质分布的模拟,提高了降水的预报效果,对模式综合预报性能的提升也有明显作用。 展开更多
关键词 PRM方案 标量平流 grapes全球预报系统 半拉格朗日 质量守恒
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GRAPES区域集合预报系统应用研究 被引量:59
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作者 张涵斌 陈静 +2 位作者 智协飞 李应林 孙云 《气象》 CSCD 北大核心 2014年第9期1076-1087,共12页
为发展GRAPES(Global and Regional Assimilation and Prediction System)区域集合预报系统(GRAPES Regional Ensemble Prediction System,GRAPES-REPS),采用集合变换卡尔曼滤波(ETKF)初值扰动方法以及多物理过程组合的模式扰动方法,基... 为发展GRAPES(Global and Regional Assimilation and Prediction System)区域集合预报系统(GRAPES Regional Ensemble Prediction System,GRAPES-REPS),采用集合变换卡尔曼滤波(ETKF)初值扰动方法以及多物理过程组合的模式扰动方法,基于业务区域模式GRAPES_MesoV3.3.2.4构建了区域集合预报系统,进行了连续40 d的批量试验,重点分析了ETKF初值扰动的结构及其演变特征,并通过概率预报检验方法对GRAPES-REPS进行了集合预报系统性能检验和降水预报检验,分析了该系统对强降水个例的预报效果。试验结果表明,GRAPES-REPS能产生较合理的集合预报初值扰动,扰动结构随流型依赖并对观测有较好的响应,且扰动成员相互正交。扰动总能量分析表明集合扰动能够随预报时效保持合理增长状态。集合预报检验表明集合预报结果优于控制预报,集合成员间在72 h预报时效内能保持合理的集合离散度。将该区域集合预报系统与业务上基于WRF模式的区域集合预报系统WRF-REPS进行了降水预报对比,表明GRAPES-REPS的降水预报能力表现要优于业务WRF-REPS。强降水个例分析表明集合预报能较好预报出强降水中心,预报效果明显优于控制预报。 展开更多
关键词 grapes 区域集合预报 集合变换卡尔曼滤波(ETKF) 多物理过程组合
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GRAPES区域集合预报尺度混合初始扰动构造的新方案 被引量:17
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作者 马旭林 计燕霞 +3 位作者 周勃旸 时洋 李琳琳 郭欢 《大气科学学报》 CSCD 北大核心 2018年第2期248-257,共10页
集合预报初始扰动能否准确反映预报误差的结构特征是决定区域集合预报质量的关键因素之一。本文针对GRAPES区域数值预报模式,发展设计了一种基于资料同化思想的混合尺度初始扰动构造新方案。该方案以全球大尺度信息为背景场,区域模式预... 集合预报初始扰动能否准确反映预报误差的结构特征是决定区域集合预报质量的关键因素之一。本文针对GRAPES区域数值预报模式,发展设计了一种基于资料同化思想的混合尺度初始扰动构造新方案。该方案以全球大尺度信息为背景场,区域模式预报作为观测资料,借助GRAPES三维变分同化系统,将高质量的全球大尺度信息与区域模式预报中质量较高的中小尺度信息有效融合,构造混合尺度区域集合预报初始扰动,并通过个例试验和批量试验,比较分析了新方案和原区域集合预报的性能。试验结果表明,基于资料同化构造的初始扰动能够有效融合全球大尺度信息和中小尺度天气系统的信息,其降水概率预报更具参考价值。总体上看,区域集合预报混合初始扰动新方案能够较好地改进区域集合预报质量,尤其是对高度场和温度场效果更为显著,但对风场的集合预报性能影响略小。 展开更多
关键词 资料同化 grapes 区域集合预报 尺度混合 初始扰动
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