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2009年秋季珠江口咸潮与风场变化的关系 总被引：2，自引：0，他引：2
利用珠江口大万山站潮位资料,横栏岛风资料和磨刀门、横门水道咸潮观测资料,采用对比和相关分析等方法,分析2009年秋季珠江口咸潮与潮位、风场变化的关系,1984～2009年秋、冬月份海平面长期变化趋势。结果表明:咸潮的发生均对应着高海面期且风向偏东,而低潮位时期且偏北风有利于补水。月平均海平面变化方面,珠江口与南海呈准同步变化。大万山站1984～2009年9、11和12月的海平面上升率高达5～6mm/月。2009年9、10月的海平面为近30年来的最高值年,11月为第3高值年。 相似文献
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一九八六年七月二十日至二十二日,第九号台风影响我区,北海、钦州地区沿海出现了历史上罕见的特大海潮(即风暴潮),北海最高潮位达5.93米,比历年同期平均最高潮位高出0.77米。据资料记载,这是三十三年以来的最高潮位。外沙及高德、北海海边街道均被潮水所淹,海堤亦被冲垮6000多米,造成了很大损失。造成这次风暴潮的原因主要有以下两个方面: 第一是天文因素。①根据月地关系推算的正常潮汐变化规律,二十一日为6眼子,二十二日为7眼子。“眼子”是沿海渔民用以表示潮位高低的一种说法,7眼子为最高 相似文献
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近海海面油类漂流扩散的研究和预测实践 总被引：4，自引：0，他引：4
根据珠江口气象站风速与潮汐站潮位资料，对1955－1998年12次El Nino过程的珠江口季风强度与海平面变化特点进行合成分析，结果表明，El Nino发生前一年冬季，珠江口冬季平均风速较常年值大0．4m/s,El Nino发生当年，月平均风速也普遍大于常年，而月平均海平面则普遍较常年偏低，其中10与11月份负距平为6cm左右。东亚地区的季风异常对珠江口海平面异常有着重大的影响。 相似文献
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珠江口近15年海平面变化特点及其与强咸潮发生的关系 总被引：1，自引：1，他引：0
通过对珠江口30多年相对海平面和近15年绝对海平面变化的研究,比较1992年12月～2008年12月南海卫星观测和珠江口验潮站观测的海平面变化趋势,认为珠江口的相对海平面（RSL）上升最主要原因是全球气候变暖、海平面上升所致;通过研究29个冬季各月西、北江冬季径流量、海平面、表层盐度的变化趋势,以及强咸潮月份的径流、海平面、盐度的对应关系,得出海平面上升是加大咸潮影响的重要因素。 相似文献
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“070304”渤海特大风暴潮的成因分析 总被引：1，自引：0，他引：1
对2007年3月4日发生在渤海的特大风暴潮天气过程，从大气环流形势、动力条件、天文条件、地形条件等方面进行了详细的分析。结果表明，长时间北高南低的地面气压场在渤海形成持久的偏东大风是造成风暴潮的重要因素；强烈的低层辐合高空辐散使地面气旋不断加强，气旋四周较强的气压梯度力是风暴潮的强迫动力之一；风应力增水作用与天文大潮相叠加直接加剧了风暴潮的强度。渤海特殊的地形特征有利于形成风暴潮天气，当地面风由东北转为西北后，渤海湾的潮位开始回落，渤海海峡的潮位继续升高，其最高潮位时间与潮位回落时间均滞后于渤海湾。 相似文献
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浙江象山县石浦气象站 《气象》1975,1(7):7-8
(一) 1974年第13号台风,于8月19日夜在石浦附近登陆,正面袭击我县。台风登陆期间,正逢农历七月初天文大潮的高潮时刻,石浦港出现7.93米的最高潮位,超过1959年建站以来最高潮他0.25米。群众反映比1956年8月1日台风袭击时的潮位还高。这次台风具有风时长(大风持续4天以上,本站极大风速达44.6米/秒)、雨量大(全县普遍降水260毫米以上。个别地方达432毫米)、潮位高的特点。这种大风、大潮、大雨同时袭击我县,在解放后的二十多年来,还是第一次。 相似文献
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渤海西岸致灾风暴潮的统计预报模型 总被引：2，自引：0，他引：2
渤海西岸是风暴潮灾害多发区,1990年代以后发生几率和灾害损失明显增加。利用气象科学和海洋水文科学相结合的方法,依据黄骅港潮汐资料,对发生在渤海西岸的风暴潮进行统计分析。结果表明,台风和强冷空气配合气旋是造成渤海西岸风暴潮的主要天气系统,偏东大风增水和天文潮叠加是造成风暴潮的直接因素;风暴潮和天文潮汐都有半日潮现象。在此基础上,建立了渤海西岸风暴潮预报模型,通过台风或冷空气配合气旋影响时增水值的计算,结合天文潮汐资料,做出最高潮位预报。应用该预报方法对渤海西岸发生的7次风暴潮进行回报,预报值与实测值基本相当,是基层台站较实用的预报方法。 相似文献
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Aminath S. Rasheed 《大气与海洋》2014,52(2):155-168
The secular trends for local tidal datums, tide ranges, and tidal harmonic constituents at 13 tidal gauge stations located along the coast of Japan were analyzed in this study. The general trends for mean higher high water (MHHW), mean high water (MHW), diurnal tide range (DTR), mean tide range (MTR), and relative mean sea level (RMSL) were positive, and for mean lower low water (MLLW) and mean low water (MLW) the trends were negative. The variation patterns were largest at Kushiro and Ofunato stations, both located in the open waters of the North Pacific Ocean. The tidal datums and tide ranges remained fairly stable at the Hakodate station, and an opposite trend was observed at the Maisaka station. The analysis of tidal harmonic constituents revealed a less pronounced pattern. The most distinct trend was observed for the M2 amplitude, which appears to be negative at a majority of the stations. The largest decrease in the M2 amplitude was observed at Kushimoto and Mera stations, also located in the open waters of the North Pacific Ocean. The negative trend is attributed to decreasing water depths at these stations, owing to small-scale local processes. 相似文献
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将8个主要平衡分潮加入到耦合模式中,对比研究潮汐对北大西洋模拟影响。由于潮汐的引入,模式模拟SST在北大西洋中纬度区域偏差显著减小,高纬度区域SST降温明显。SST模拟的改变使潮汐试验的海表净热通量模拟误差下降了约30%,但高纬度海冰显著增加。模式中引入潮汐对北大西洋上层环流,尤其是西边界流的路径模拟改进显著,这是SST及海表净热通量模拟改变的主要原因。同时,北大西洋上层和深层西边界流在潮汐的作用下,都表现出环流减弱的特点,这也使得大西洋经向翻转环流在26.5°N处上层2 km的输送减弱,与观测数据更为接近。较弱的大西洋经向翻转环流导致海洋热量在中低纬度聚集而无法输送到高纬度区域,这是造成潮汐试验模拟的海温在中低纬度偏高、高纬度偏低的原因,较弱的热输送也同时导致了潮汐试验中北半球海冰面积增加。 相似文献
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红树林的滨海湿地生境使得它同陆生植被、水体-陆生植被混合像元难以区分,且红树林在遥感图像上的空间分布还随着潮位的变化而变化,因此基于通常采用的单一潮位遥感图像无法精确提取红树林空间信息.基于高潮位和低潮位TM遥感图像,尝试利用红树林的潮位周期性变化和滨海湿地特征来精确提取红树林空间分布信息.研究结果表明：基于缨帽变换和潮差信息提取的WIL+WIH、GVIL和GVIL-GVIH（WI、GVI分别为Wetness Index、Greenness Vegetation Index,下标L和H分别表示低潮位和高潮位）等指数能使红树林与其他地物之间具有很好的可分性;进一步采用最大似然法对红树林进行分类识别,通过结合潮位信息能精确提取红树林,其中制图精度和用户精度分别为94.57%、98.8%. 相似文献
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Sea level rise has become an important issue in global climate change studies. This study investigates trends in sea level records, particularly extreme records, in the Pearl River Estuary, using measurements from two tide gauge stations in Macau and Hong Kong. Extremes in the original sea level records(daily higher high water heights) and in tidal residuals with and without the 18.6-year nodal modulation are investigated separately. Thresholds for defining extreme sea levels are calibrated based on extreme value theory. Extreme events are then modeled by peaks-over-threshold models. The model applied to extremes in original sea level records does not include modeling of their durations, while a geometric distribution is added to model the duration of extremes in tidal residuals. Realistic modeling results are recommended in all stationary models. Parametric trends of extreme sea level records are then introduced to nonstationary models through a generalized linear model framework. The result shows that, in recent decades, since the 1960 s, no significant trends can be found in any type of extreme at any station, which may be related to a reduction in the influence of tropical cyclones in the region. For the longer-term record since the 1920 s at Macau, a regime shift of tidal amplitudes around the 1970 s may partially explain the diverse trend of extremes in original sea level records and tidal residuals. 相似文献
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In an effort to assess the reliability of satellite altimeter systems, the authors conduct a comparative analysis of sea level data that were collected from the TOPEX/POSEIDON (T/P) altimeter and 10 tide gauges (TG) near the satellite passing ground tracks. The analysis is made using datasets collected from marginal sea regions surrounding the Korean Peninsula at T/P cycles of 2 to 230, which correspond to October 1992 to December 1998. Proper treatment of tidal errors is a very critical step in data processing because the study area has very strong tide. When the T/P data are processed, the procedures of Park and Gamberoni (1995) are adapted to reduce errors associated with the tide. When the T/P data are processed in this way, the alias periods of M2, $2, and K1 constituents are found to be 62.1, 58.7, and 173 days repectively. The compatibility of the T/P and TG datasets are examined at various filtering periods.The results indicate that the low-frequency signals of the T/P data can be interpreted more safely with longer filtering periods (such as up to the maximum selected value of 200 days). When RMS errors for the 200-day low-pass filter period are compared with all 10 tidal stations, the values span the range of 2.8 to 6.7 cm. The results of a correlation analysis for this filtering period also show a strong agreement between the T/P and TG datasets across all stations investigated (e.g., p-values consistently less than 0.001). Hence according to the analysis, the conclusion is made that the analysis of surface sea level using satellite altimeter data can be made safely with reasonably extended filtering periods such as 200 days. 相似文献
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Richard D. Ray 《大气与海洋》2016,54(2):108-116
Since the late 1990s the semi-diurnal tide at Churchill, on the western shore of Hudson Bay, has been decreasing in amplitude, with M2 amplitudes falling from approximately 154?cm in 1998 to 146?cm in 2012 and 142?cm in 2014. There has been a corresponding small increase in phase lag. Mean low water, decreasing throughout most of the twentieth century, has levelled off. Although the tidal changes could reflect merely a malfunctioning tide gauge, the fact that there are no other measurements in the region and the possibility that the tide is revealing important environmental changes calls for serious investigation. Satellite altimeter measurements of the tide in Hudson Bay are complicated by the seasonal ice cover; at most locations less than 40% of satellite passes return valid ocean heights and even those can be impacted by errors from sea ice. Because the combined TOPEX/Poseidon, Jason-1, and Jason-2 time series is more than 23 years long, it is now possible to obtain sufficient data at crossover locations near Churchill to search for tidal changes. The satellites sense no changes in M2 that are comparable to the changes seen at the Churchill gauge. The changes appear to be localized to the harbour, or to the Churchill River, or to the gauge itself. 相似文献
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2030年上海地区相对海平面变化趋势的研究和预测 总被引：1，自引：0，他引：1
从全球气候变化区域响应角度,依据1912-2000年吴淞验潮站年平均潮位资料,构建灰色线性回归组合模型,并将其与最小二乘法和小波变换相结合,分析以吴淞为代表的上海绝对海平面长期变化趋势和周期变化规律。由此预测2030年上海绝对海平面相对2011年的上升值为4 cm,结合已公布的构造沉降和城市地面沉降、流域水土保持和大型水利工程及人工挖沙导致的河口河槽冲刷、河口围海造地和深水航道及跨江跨海大桥导致水位抬升等叠加效应及其变化趋势,预测2030年上海市相对海平面上升10～16 cm,陆地海平面上升有7个风险分区。 相似文献