气象资料同化的研究进展   总被引：13，自引：5，他引：13  

陈东升  沈桐立  马革兰  何迪 《南京气象学院学报》2004,27(4):550-564

回顾了国内外有关气象资料同化的研究进展，介绍了当前资料同化主要方法的理论基础、优缺点及应用研究。重点介绍了伴随方法和遗传算法在四维变分同化中的具体应用。其中，遗传算法的引入为资料同化的研究提出了新的思路。  相似文献   

Correlation of the Late Cenozoic endogenic events and climatic variations in Central Asia     

V. V. Yarmolyuk  M. I. Kuzmin 《Stratigraphy and Geological Correlation》2006,14(2):105-125

Trend of climatic changes in geological history of the Earth was determined by gradual decrease in the global surface temperature. Substantial deviations from this trend depended on the prevalent type of volcanism: predominantly explosive volcanism at convergent boundaries between lithospheric plates led to cooling and onset of glacial epochs, while intense intraplate volcanism strengthened greenhouse effect and resulted in global warming. During cold epochs, orogenic processes played an important role in climatic variations. The most frequent and regular climatic variations are controlled by the Earth position in solar orbit (Milankovitch cycles). The Late Cenozoic variations of cold climate were interrelated with orogenic processes caused by collision between the Indian and North Asian lithospheric plates. The first event of considerable cooling in the Northern Hemisphere (2.8–2.5 Ma ago) coincided with a rapid growth of mountains throughout the collision belt. The Tibetan Plateau formed in South Asia. In Central Asia, the large (> 1.5 × 10⁶ km²) Khangai-Altai-Sayan mountain system appeared 3 Ma ago. Total area subjected to orogenic processes in Central and South Asia exceeded 9 × 10⁶ km². The intense intraplate volcanism suggests that sublithospheric mantle was involved into orogenic processes. Alternation of glacial and interglacial climatic epochs during the last 1.8 m.y. is recorded in Central Asia. These climatic variations are compatible with the Milankovitch cycles. As is established, climatic events recognizable in the Baikal sedimentary record are correlative with interglacial and glacial epochs detectable in volcanic lavas of the East Sayan Mountains. There are indications of lava eruptions into ice during the cold periods. It is assumed therefore that all the cooling epochs detectable in the Baikal sedimentary record after 1.8 Ma were associated with development of mountain glaciation that formed glacial sheet up to 3 km thick and 100 000 km² in size. During the Brunhes Chron, there were eight glaciations at least. The endogenic (volcanism and orogeny) and exogenic (glaciation) processes during the last 3 m.y. are shown to be correlative. The intermittent development and degradation of thick ice sheets was responsible for oscillation of lithospheric load on the asthenosphere, and this caused periodical magma generation in marginal parts of volcanic provinces.  相似文献   

近十年来分析化学测试技术进展   总被引：1，自引：0，他引：1  

周丽沂  张勤 《物探与化探》1997,21(6):418-424

本文介绍物化探研究所1988～1997年十年中化探分析测试技术的新进展。文章中就地球化学标准物质研制、地球化学样品多元素分析系统、分析仪器的研制、分析测试新方法新技术的研究开发、应用和推广以及专业人才培养诸方面的情况分别进行了论述。  相似文献   

90年代水文学研究的进展和趋势   总被引：12，自引：2，他引：12       下载免费PDF全文

刘苏峡  刘昌明 《水科学进展》1997,8(4):365-369

从国际水文科学协会(IAHS)在第21届国际地球物理与大地测量(IUGG)大会的动态,展示90年代以来水文学研究中几个值得注意的进展和趋势。土壤水分和地下水质的监测正在和已经引起广泛注意。地表-大气交换过程研究的兴起将有助于对降雨-径流过程中间过程的研究。藉助于其他学科的参与,水文模型在为气候模式等提供参数的同时,也充实了自身。但水文模型本身还没有明显突破。尺度问题、水资源可持续性利用、不确定性和可预见性仍然是水文学研究的重点。  相似文献   

长白山天池火山研究进展   总被引：25，自引：0，他引：25  

刘若新  魏海泉 《地震地磁观测与研究》1996,17(4):2-11

长白山天池火山距今４１０５年以来至少发生过两次大规模喷发。其最近的一次大喷发发生于公元８５０～１０４０年间。估计了这次喷发的喷发物体积和Ｃ１，Ｆ，Ｓ等的释放量。数值模拟表明，该次大喷发对全球气候变化产生过重要影响，最近的地球物理探测结果显示，在该火山下面存在地壳和上地幔双层岩浆房。认为该火山现在仍是一座具潜在灾害性大喷发危险的现代活动火山。  相似文献   

中国强地面运动研究进展          下载免费PDF全文

许力生  俞言祥  陈运泰 《地震学报》2003,25(5):475-478

简要总结了近年来我国在强地面运动资料的处理、近断层地面运动的影响因素、强地面运动的模拟和宽频带反应谱等方面的研究工作．同时，回顾与展望了我国在强地面运动研究方面的国际合作进展．   相似文献   

青海乌兰盆地东缘断裂带的新活动特征   总被引：1，自引：0，他引：1  

袁道阳  刘小龙  张培震  刘百篪  郑文俊  郭华  曹娟娟 《地震研究》2003,26(3):265-270

在青海乌兰盆地东缘山前冲洪积扇上新发现了一条长约 2 2km的逆冲断裂带 ,该断裂带是NNW向的鄂拉山右旋走滑断裂带北段西侧的次级挤压构造。其新活动受主断裂带的制约和影响 ,地貌上表现为明显的正向断层陡坎。晚更新世以来其垂直滑动速率为 0 11～ 0 17mm/a ,全新世晚期的垂直滑动速率为 0 35mm/a。综合探槽剖面及断层陡坎年代可以确定四次古地震事件 ,其年代分别为距今 2 4 6 5 0± 85 0a、 14 2 0 0± 70 0a、 5 2 0 0±5 2 0a和 2 2 5 0± 380a ,古地震活动具有不均匀性。  相似文献   

海南琼北复式含水层系统水循环特征          下载免费PDF全文

郭纯青 《水科学进展》2003,14(3):379-383

目前,琼北复式含水层系统(面积4300km2)的水循环方式,以垂向互补互渗为主,水平径流为辅,最大限度截取地下水入海径流量.海水与复式含水层系统发生水量交换必须同时具备两个条件:(1)存在水量交换通道;(2)有势能差(位头、压头和咸淡水密度差别产生的重力势头组成).由于琼北复式含水层系统地下水资源多年连续被开采,承压自流水位在15～20年前就已降低至海平面之下,但至今尚未发现明显的海水入侵迹象.  相似文献   

The influence of tectonically derived relief and climate on the extent of the last Glaciation east of the Patagonian ice fields (Argentina, Chile)     

Gerd Wenzens   《Tectonophysics》2002,345(1-4)

Two large ice fields between 46°30′ and 51°30′S cover the Patagonian Andes. The North and South Patagonian Ice Fields are separated by the transandine depth line at 47°45′ to 48°15′S. Canal and Río Baker run through this depression. The two ice fields are generally considered relics of a continuous ice cap, which covered the entire Patagonian Andes from 39° to 52°S and extended far into the eastern foreland of the Andes. This assumption is not correct for the 200-km-long section of the Andes between Lago Pueyrredón (Lago Cochrane in Chile) (47°15′S) and Lago San Martín (Lago O'Higgins in Chile) (48°45′S). The lack of a continuous ice cap extending far into the east is caused by the transandine depth line, playing a crucial role in the fluvial erosion and the glacial scouring of this tectonic zone. This depression formed a river system (e.g. Río Baker, Río Bravo and Río Mayer) that drains towards the west. Reconstruction of the maximum glacial advance of the last ice age shows that the eastern outlet glaciers of the two ice fields between Lago San Martín and Lago Pueyrredón did not drain towards the east, but rather followed the general gradient of the transandine depth line. In this area the eastern flank of the Andes between Monte San Lorenzo (3770 m) and Sa. de Sangra (2155 m) supported valley glaciers, which were independent of the expanding ice fields. Only a few valley glaciers advanced towards the Patagonian Meseta. The terminal moraines of these glaciers were erroneously interpreted as the eastern edge of a continuous ice cap. North of 47°30′S the outlet glaciers of the NPI advanced 200 km during the LGM and the late glacial advances nearly reached to 71°W. In contrast, south of 49°S glacier expansion was comparatively less: The LGM is situated only 85–115 km east of the present margins of the large outlet glaciers (O'Higgins, Viedma, and Upsala), and no late glacial advance reached 72°W. These considerable differences of glacier expansion were influenced by the northward migration of the westerly precipitation belt during glacial cycles. There is tentative evidence that the glaciers advanced three times in the period from 14 000 to 9 500 ¹⁴C years BP.  相似文献   

有机柱撑粘土(蒙脱石)的研究进展   总被引：10，自引：1，他引：10  

朱建喜  何宏平  郭九皋  杨丹 《矿物岩石地球化学通报》2002,21(4):234-237

有机柱撑蒙脱石是近年来受到广泛关注的一类有机-无机粘土复合材料，其优异的性能使其在许多领域都有巨大的应用潜力。本综述了有机柱撑蒙脱石的起源、发展、主要类型，探讨了有机柱撑蒙脱石的研究方向。  相似文献