Cluster analysis of Tropical Cyclones making landfall on the Korean Peninsula

Cluster analysis has been performed on the tracks of 51 Tropical Cyclones (TCs) that made landfall on the Korean Peninsula (KP) for the period of 1951–2004. The classification technique of the landfalling tracks used in this study was the fuzzy clustering method (FCM) and the resultant silhouette coe?cient suggested four clusters as an optimal cluster number. Most TCs of Cluster 2 and Cluster 3 (C-23) tended to pass through mainland China before landfall, but those of Cluster 1 and Cluster 4 (C-14) tended t...     

The climate variabilities of air temperature around the Korean Peninsula

In this study, changes in climatological conditions around the Korean Peninsula are estimated quantitatively using various types of high order statistical analyses. The temperature data collected from Incheon station have been analyzed for the assessment of the climate variation. According to our analysis, the climate changes observed over the Korean Peninsula for the last century are similar to the global observational data in many respects. First of all, the warming trend [ 1.5℃ (100 yr)^-1] and the overall evolving pattern throughout the century are quite similar to each other. The temperature change in the Korean Peninsula is about two to three times larger than that of the global scale which may partially be ascribed to the influence of urbanization at mid and high latitudes. In this work, a new Winter Monsoon Index (WMI) is suggested based on the European continental scale circulation index (EU1) pattern. Our WMI is defined as the normalized sea level pressure (SLP) difference in the winter period between the centers of the East Sea and west of Lake Baikal in Siberia, the two eastern centers of the EU1 action patterns. A strong similarity is found between the time series of the WMI and surface air temperature at Incheon. The WMI has decreased gradually since the 1920s but has shifted to a rapid increasing trend in the last two decades; it was in fact accompanied by a weakening of the Siberian High and a decreasing of the northerly during winter. Our findings of the close correlations between the surface air temperature at Incheon and the WMI strongly indicate that our newly suggested index is unique and can be used as an efficient tool to predict climate variability in Korea.     

A Comparison of GPS- and NWP-derived PW Data over the Korean Peninsula

Precipitable Water (PW) derived from Global Positioning System (GPS)measurements and numerical weather prediction (NWP) model analysis data werecompared to further evaluate the efficacy of applying GPS-derived PW to theNWP model. The spatial and temporal variations of GPS-derived PW during arainfall event were also examined.GPS-derived PW measurements show good agreement with the behavior of watervapor at a high spatial resolution during the analysis period. Temporalanomalies of GPS-derived PW moving along with the front are successfullydetected by the GPS array. Large positive anomalies of GPS-derived PW areindicated immediately before a rainfall event, and the intensity of thesepositive anomalies do not seem to decrease significantly as theprecipitation system passes. These results indicate that the Korean GPSnetwork may have great potential as a PW sensor over the Korean Peninsula.In contrast with GPS-derived PW, NWP-derived PW shows negative biases. Thesebiases appear to stem mainly from the differences between modeled and actualGPS site elevations, as GPS sites were generally located at elevations lowerthan those employed by the NWP model. However, there still exists adiscernable dry bias after a PW correction is applied to NWP-derived PW.GPS-derived PW better reflects the spatial and temporal moisture variationsof precipitation systems, as compared to NWP-derived PW. These resultsprovide entirely new information for improving the regional NWP system,since GPS-derived PW produced with data from the Korean GPS network may beincorporated into the NWP model to improve rainfall forecasts.     

大别-苏鲁造山带在朝鲜半岛的延伸方式——基于~(40)Ar/~(39)Ar构造年代学的约束

本文结合野外构造变形特征观测,在朝鲜半岛的不同构造单元采集14件糜棱岩和片麻岩样品进行~(40)Ar/~(39)Ar年代学分析,在此基础上通过对比朝鲜半岛与大别造山带不同构造单元的变形特征,探讨大别苏鲁构造带在朝鲜半岛的东延特征,取得如下认识:朝鲜半岛中部的主要构造带在中生代经历了碰撞阶段(~210Ma)、逆冲推覆(200~150Ma)、造山后伸展阶段(140~90Ma)三个主要的构造过程;从变形期次和变形特征看,临津江构造带与大别造山带的北淮阳构造带、苏鲁构造带北部威海地区具有可比性,沃川构造带与南大别构造带有相似之处;在朝鲜半岛,自临津江带至沃川带构成了较完整的中生代碰撞造山带,即大别-苏鲁造山带的东延部分,原认为的"京畿地块"应属造山带的一部分。     

基于MODIS数据的朝鲜半岛土地利用变化信息提取

以朝鲜半岛为研究区域, 基于2000年和2007年的MOD IS数据, 应用线性光谱混合模型进行像元组分分解并提取分类特征, 对像元组分分解后有错分的地物类型结合纹理进行分析, 以决策树模型进行土地利用分类。结果表明, 像元组分分解后的决策树分类结果总体精度达78.346 5% , Kappa系数达0.681 3。与像元组分分解前最大似然法和决策树分类结果相比, 决策树分类精度优于最大似然法, 且像元组分分解方法提高了分类精度。经2000年和2007年像元组分分解后的决策树分类结果对比: 朝鲜耕地面积增加; 韩国耕地面积减少, 居民地面积增加。     

汉服:漂洋过海 异域生花

中国自古有衣冠上国、礼仪之邦的美誉。始于黄帝,备于尧舜的汉服是华夏文明的产物,经历过辉煌也曾在剃发易服政策下几近消亡。我们无法忘怀在四书五     

丹东市赴朝边境旅游发展研究

丹东市是中国最大的边境城市，赴朝旅游是丹东市特许经营的旅游项目，赴朝旅游是丹东市特许经营的旅游项目，赴朝旅游是其旅游业发展的龙头，赴朝旅游主要受制于朝鲜半凫局势的走向，其发展趋势是不断增长的，并且市场具有较大的不稳定性。赴朝旅游带动丹东市旅游业全面发展的同时，也为朝鲜经济的全面振兴注入了活力。     

中国东部-朝鲜半岛中生代板块边界划分研究进展

中朝板块与扬子板块在晚二叠世-三叠纪期间的碰撞形成大别-苏鲁造山带,这一碰撞结合带过黄海在朝鲜半岛的延伸方式一直是国内外学者关注的焦点.由于朝鲜半岛地质构造的复杂性,对于这一问题仍存在诸多不同的观点,主要有两类:①沿临津江带或沃川带或京畿地块进入朝鲜半岛;②没有延入朝鲜半岛.深部地质与地球物理资料显示区内两板块深部结合带位置可能与表层存在较大差异,这更加深了板块边界划分研究的复杂程度.本文总结了上述两个板块结合带划分研究的各类观点,回顾下扬子上、下地壳归属特征差异的主要研究进展,认为产生观点差异的主要原因是对区内中新生代整体地质演化认识不足,尤其是缺乏足够可靠的深部信息,从而提出地质、地球化学、地球物理资料的综合解释是今后解决这一问题的发展方向,指出黄海地区海-陆构造关系为国内下一阶段的研究重点.     

中朝地台的中奥陶统—下石炭统及其古地理和构造含意

华北地台是我国最大的早前寒武纪克拉通,一般认为其演化史中一个显著的特征是早奥陶世末到中石炭世初存在着巨大的沉积间断,但是近来的研究表明,地台外缘仍发育着上述间断期间的地层,从而可据此揭示出该时期地台的地史经历、大陆边缘的位置和性质,早古生代期间地台内部主要受南部被动大陆边缘的影响,海水源自古秦岭洋,朝鲜半岛上的所谓“临津江带”不宜与秦岭造山带对比,鄂尔多斯盆地西缘大陆边缘的确定,提示早古生代时阿拉善地块可能不属于中朝地台,周边大陆边缘的存在表明中朝地台是一个完整的陆块,不象是与杨子陆块来自统一的“中国地台”。     

朝鲜平南盆地古元古界-下古生界沉积岩碎屑锆石年龄谱对比及意义

中朝古陆(华北古陆)平南盆地面积~25000km~2,位于朝鲜半岛中部,发育从中元古界到下古生界地层,但经历了低级变质作用(绿片岩相及以下)。变质基底岩石中有一套角闪岩相-麻粒岩相的变质的古元古界地层。本文根据盆地不同时代沉积岩碎屑锆石/变质锆石U-Pb LA-ICP MS年龄数据讨论沉积源区的变化,并对区域演化进行制约。甑山群/杂岩为盆地基底岩系,变质砂岩样品中碎屑锆石出现ca.2500~2100Ma的年龄峰值。另外,36.5亿年的碎屑锆石是朝鲜迄今发现的最古老碎屑锆石;夕线榴片麻岩样品记录了~1850Ma(1859±9Ma)的变质年龄;推测甑山群沉积于ca.2100~1900Ma,变质于1850 Ma。黄海群局限分布于朝鲜半岛中部,碎屑锆石年龄谱显示~1850 Ma的峰值,可见~1250 Ma的年龄,推测对应物源为古元古代基底岩浆岩和变质岩系;结合其上覆直岘群的沉积时代,推测地层沉积于ca.1250~1000Ma。直岘群是平南盆地分布最广的地层之一,底部长峰组样品显示明显的~1850Ma的峰值,而其上第二个和第三个组则显示明显的ca.1400~1600Ma和ca.1000~1200 Ma年龄峰值,~1850 Ma年龄很少;推测直岘群开始沉积时,物源主体是盆地基底岩系,但之后出现大量中元古代物质;推测其沉积时代为ca.1000~900Ma。黄州群有~1850Ma和~2500Ma的峰值,另外,还有较少的ca.1000~1200Ma及1400~1600 Ma年龄,表明沉积物源主体仍是基底岩系,可能有中新元古代沉积岩(黄州群-直岘群)的再沉积。这些沉积岩碎屑锆石年龄峰值与辽东和山东半岛沉积地层相似,并且中新元古代地层中均有大量1000~1200Ma及1400~1600Ma的物质,推测可能来自华北古陆之外,如圣弗朗西斯科克拉通。