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41.
Su-Cheng Pai Sen Jan Tung-Yuan Ho Jin-Yuan Liu Ken-Sheng Chu Wen-Huei Lee Cheng-Yun Wang Ping-Yi Huang Hung-Yu Hsu Yiing-Jang Yang 《Journal of Oceanography》2017,73(6):711-723
Significant variations of phosphate and silicate concentrations have been observed in seawater from selected industrial pipelines at intake depths between 400 and 710 m off the Hualien coast, eastern Taiwan, revealing a strong vertical movement of water mass in this intermediate layer. An intensive monitoring experiment was carried out, in which pipeline seawater from three land-based pumping stations and seawater collected by a research vessel were obtained and analyzed in parallel during a 2-day observation period. The results showed clearly that the changes of nutrient concentrations in both pipeline and shipboard samples followed a semidiurnal cycle. The maximum vertical displacement occurred in the 300–800 m layer with a scale as surprisingly large as 100 m, when compared with that observed in other areas. The tidal cycles for different layers may not synchronize with surface tide or each other. Empirical equations have been implemented between nutrient concentrations and temperature for the Hualien off-shore area. The equation can be used to check temperature variation of the intermediate water by measuring either phosphate or silicate in pipeline seawater. 相似文献
42.
Nutrient budgets for the South China Sea basin 总被引：3，自引：0，他引：3
Varying atmospheric forcing and an elaborate geography make for a complex flow in the South China Sea (SCS). Throughout the year, the surface waters of the Kuroshio flow into the SCS, while the surface waters of the SCS flow out through the Bashi Channel. Cumulatively, there is a small (1 Sv) net outflow of surface water (0–350-m depth) from the SCS in the wet season, but a net inflow (3 Sv) in the dry season through the Bashi Channel. The differences are mainly made up by inflow and outflow of Sunda Shelf Water in the wet and dry seasons, respectively.Seawater, phosphorus, nitrogen and silicate budgets were calculated based on a box model. The results point out an intermediate water outflow (350–1350-m depth) into the West Philippine Sea (WPS) through the Bashi Channel in both the wet and dry seasons, though this, along with the nutrients it carries, is slightly larger in the dry season (2 Sv) than in the wet (1.8 Sv). More importantly, the export of nutrient-laden SCS intermediate water through the Bashi Channel subsequently upwells onto the East China Sea (ECS) shelf. The denitrification rate for shelves in the SCS is 0.11 mol N m−2 year−1, calculated by balancing the nitrogen budget. The oxygen consumption and the nutrient regeneration rates, based on the mass-balance and the one-dimensional advection–diffusion models, stand between those for the Bering Sea and the Sea of Japan. 相似文献
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Tsu-Chiang Lei Shiuan Wan Tien-Yin Chou Hung-Chieh Pai 《Environmental Earth Sciences》2011,63(5):981-997
Debris flow is often performed through identifying and analyzing the soil condition, hydraulic, geomorphological factors and
vegetation conditions. In the present study, a spatial information analysis system is combined with a linear statistical method
(principle components analysis with linear discriminant analysis, PCA + LDA) and an advanced data mining technique (discrete
rough sets, DRS) to investigate the debris flow occurrence based on geomorphological and vegetation conditions factors. The
analyzed data sources include (1) digital elevation model: to investigate the variation in the landscape, and (2) remote sensing
data: to analyze the vegetation and plant conditions on the ground surface. The objective of this research is to define a
method with the ability to forecast the level of debris flow susceptibility through the parallel study of statistical outcomes
(PCA + LDA) and data mining results (DRS). The outcomes from PCA + LDA are inadequate due to the thresholds of the influenced
variables not being examined. In this study, the DRS approach not only showed satisfactory results for the thresholds of influenced
variables in the study area, but also the occurrence rules of debris flow are generated. Finally, the results show superior
classification accuracy (70.8% for debris flow occurrence) for the DRS method over those of PCA + LDA analysis (54.2% for
debris flow occurrence) for the analysis of debris flow occurrence. Therefore, this is an encouraging preliminary approach
in the hazard assessment of debris flow. 相似文献
45.
苏里格气田西部的二叠系石盒子组8段(He-8)和山西组山1段(Shan-1)是主要的天然气产层, 是致密砂岩准连续型气藏, 气水关系复杂.本文通过岩石薄片、电镜扫描、生烃模拟、古构造恢复技术, 分析总结了盒8段和山1段的油气基础地质条件和致密砂岩天然气成藏的主控因素, 并将成藏过程分为4个阶段.结果表明较低生烃强度和东高西低的构造背景决定了现今大面积的含水局面, 区块烃源岩(煤层厚度)、储层物性(规模和非均质性)和山1段隔夹层主要控制了局部天然气富集区(甜点).晚期的新构造运动导致早期天然气藏中已形成的气水系统再分配、调整, 从而造就了现今盒8段-山1段气藏复杂的气水格局. 相似文献
46.
利用三次卷积方法实现新一代天气雷达产品电视播出 总被引：1，自引：0，他引：1
针对地市级电视天气预报节目中雷达网制作环节存在的问题,使用VB编程丁具,读取单站新一代天气雷达产品的第19类数据(反射率因子),利用三次卷积插值算法进行放缩,生成可适用绝大多数非编软件播出的带有Alpha通道的TGA文件序列,并且可以通过Alpha通道叠加背景图片或动态视频,实现雷达产品在电视天气预报节目中播出.实践证明,三次卷积插值方法不仅内插精度较高、图像的颜色连续,所得图像质量较其它插值方法明显提高,符合播出标准,而且还能较好地保留图像的高频成分. 相似文献
47.
Spatial and temporal relationships between global land surface air temperature anomalies and Indian summer monsoon rainfall 总被引：3，自引：0，他引：3
Summary Using the 60 year period (1931–1990) gridded land surface air temperature anomalies data, the spatial and temporal relationships between Indian summer monsoon rainfall and temperature anomalies were examined. Composite temperature anomalies were prepared in respect of 11 deficient monsoon years and 9 excess monsoon years. Statistical tests were carried out to examine the significance of the composites. In addition, correlation coefficients between the temperature anomalies and Indian summer monsoon rainfall were also calculated to examine the teleconnection patterns.There were statistically significant differences in the composite of temperature anomaly patterns between excess and deficient monsoon years over north Europe, central Asia and north America during January and May, over NW India during May, over central parts of Africa during May and July and over Indian sub-continent and eastern parts of Asia during July. It has been also found that temperature anomalies over NW Europe, central parts of Africa and NW India during January and May were positively correlated with Indian summer monsoon rainfall. Similarly temperature anomalies over central Asia during January and temperature anomalies over central Africa and Indian region during July were negatively correlated. There were secular variations in the strength of relationships between temperature anomalies and Indian summer monsoon rainfall. In general, temperature anomalies over NW Europe and NW India showed stronger correlations during the recent years. It has been also found that during excess (deficient) monsoon years temperature gradient over Eurasian land mass from sub-tropics to higher latitudes was directed equatowards (polewards) indicating strong (weak) zonal flow. This temperature anomaly gradient index was found to be a useful predictor for long range forecasting of Indian summer monsoon rainfall.With 12 Figures 相似文献
48.
W.-L. Cheng J.-L. Pai B.-J. Tsuang C.-L. Chen 《Meteorology and Atmospheric Physics》2001,78(1-2):11-21
Summary
Recent studies have shown that regional orography and synoptic patterns greatly affect ozone concentrations. The orography
of certain locations is unfavorable for pollutant dispersion, and specific synoptic patterns in these locations lead to serious
air pollution episodes. Frequent ozone episodes (defined as hourly ozone ≥ 120 ppbv) in west-central Taiwan during recent
years have generated much concern. High ozone days (defined as hourly ozone ≥ 80 ppbv) are also occurring more frequently.
High ozone days occur mainly during autumn, but there has been no clear linear relationship demonstrated between any single
meteorological variable and pollutant concentration. In this study, statistical data from 1997–1999 has shown that high ozone
levels occur with two types of synoptic patterns. The first type consists of a continental anticyclone emanating from mainland
China which is swept towards Taiwan. The second is a tropical low pressure system moving northwards closer to Taiwan.
West-central Taiwan is located in the lee of the Central Ranges (altitude of 2500 ∼ 3500 m). These synoptic patterns are unfavorable
for pollutant dispersion and cause high ozone days.
Received October 14, 2000/Revised January 5, 2001 相似文献
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2021年4月印度尼西亚海军“南伽拉402”号潜艇在巴厘岛以北约60海里（111.12 km）处发生沉没,分析表明大振幅海洋内孤立波作用可能是事故原因之一。基于大振幅内孤立波eKdV理论与Morison公式建立了内孤立波作用下潜艇的运动学模型,揭示不同内孤立波振幅、潜艇潜深条件下潜艇的运动响应特性,进一步说明内孤立波可能造成印度尼西亚潜艇失事。结果表明：内孤立波对潜艇的运动状态产生巨大影响。垂直方向上潜艇在短时间内产生大幅度掉深,而水平方向上其运动方向在密度界面上或界面处与内孤立波传播方向一致,界面下则相反,且内孤立波产生的垂向力矩可能造成潜艇倾覆。不同波幅、潜深下潜艇表现出不同的运动响应规律。研究表明印度尼西亚潜艇失事可能是潜艇执行任务过程中遭遇了较大振幅内孤立波,导致其发生大幅度、迅速掉深。 相似文献