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1.
The long-term time series analysis of the SST (sea surface temperature) in the Eastern Equatorial Pacific Ocean and the monthly MSL (mean sea level) in the tropical Pacific Ocean is conducted. Their quasiperiodic and low-frequency oscillation features are revealed. The significant periods of low-frequency fluctuations for monthly MSL in the area of 20°N-20° S are between 43. 5 months and 50. 0 months, approximating closely to 47. 6 months which is the significant period of SST in the Eastern Equatorial Pacific Ocean. From the results of space-spectral analysis, the low-frequency fluctations of monthly MSL in the tropical Pacific Ocean appear to have a anticlockwise circularly-propagating pattern, which is, the Eastern Pacific Ocean (off-shore of Mexico) →the area of NEC (North Equatorial Current) →the Western Equatorial Pacific Ocean→the area of NECC (North Equatorial Counter-Current)→the Eastern Equatorial Pacific Ocean. The phases of the pattern correspond to those of El Nino cycle. On the basis 相似文献
2.
ＴｒｅｎｄａｎａｌｙｓｉｓｏｆｒｅｌａｔｉｖｅｓｅａｌｅｖｅｌｒｉｓｅｏｒｆａｌｌｏｆｔｈｅｔｉｄｅｇａｕｇｅｓｔａｔｉｏｎｓｉｎｔｈｅＰａｃｉｆｉｃ￥ＭａＪｉｒｕｉ；ＴｉａｎＳｕｚｈｅｎ；ＺｈｅｎｇＷｅｎｚｈｅｎａｎｄＣｈａｉＸｉｎｍｉｎＩｎｓｉｔ... 相似文献
3.
太平洋海域海平面变化的灰色系统分析 总被引：3，自引：1，他引：3
应用灰色系统理论，对太平洋海域４８个长期验潮站的月均海平面分别建立了ＧＭ（１，１）模型。ＧＭ（１，１）模型能较好地反映太平洋海域的海平面变化的趋势，它除了能给出连续的海平面变化速率外，同时能方便地给出海平面变化的加速率。模拟结果表明，在太平洋地壳均衡假设下，太平洋海域的月均海平面以平均速率０．１７ｃｍ／ａ上升。在太平洋海域所取的４８个长期验潮站中，有４０个站在加速上升，全部站的平均加速度为０．０００２９ｃｍ／ａ２。且加速率逐渐增大。当然这些加速率都很小，但作为一种普遍性的趋势，这已足以说明：太平洋海域的海平面在加速上升 相似文献
4.
Ｒｅｓｅａｒｃｈｏｎｔｈｅｓｐｅｃｔｒａｌａｎａｌｙｓｉｓａｎｄｔｅｓｔｍｅｔｈｏｄｏｆｐｅｒｉｏｄｓｉｇｎａｌｓｉｎｍｏｎｔｈｌｙｍｅａｎｓｅａｌｅｖｅｌ￥ＭａＪｉｒｕｉ；ＴｉａｎＳｕｚｈｅｎ；ＺｈｅｎｇＷｅｎｚｈｅｎａｎｄＣｈａｉＸｉｎｍｉｎ（Ｒ... 相似文献
5.
利用环日本岛沿岸38个验潮站连续36 a的实测水位资料,分析了环日本岛沿岸平均海平面的长期变化特征,结果表明平均海平面的异常变化在1984年前后发生较大转折,近20多年来主要呈现持续上升趋势,部分站位在1997年前后也有较明显的下降趋势,表明海平面的长期变化中存在较长周期的波动情况。通过对所有验潮站的日平均海平面序列进行平均,发现与西北太平洋SST异常变化呈正相关,相关系数为0.908;与太平洋年代际变化(PDO)指数呈负相关,相关系数为-0.6;与西北太平洋风旋度场的异常变化呈正相关,相关系数为0.402。结果表明环日本岛沿岸平均海平面的长期变化受到海水热膨胀效应、太平洋年代际变化以及风应力引起的海水堆积和流失等因素的影响。同时,发现从2000年开始西北太平洋的SST开始下降,而平均海平面仍然在持续上升,其上升原因还需作进一步研究与探讨。 相似文献
6.
The present study investigated the variability of monthly mean sea level data and discussed its relation with climatic events in the Red Sea during 1958–2001. The data were obtained from Simple Ocean Data Assimilation (SODA), for three different locations (north, central and south) in the Red Sea. Spatial and temporal variability as well as trends and periodicity of sea level time series records in the three locations was investigated using One-way ANOVA test, weighted running mean filter and autocorrelation spectral analysis. Results revealed that mean sea level in the northern Red Sea was permanently lower than its central and southern parts. Moreover, the mean sea level during winter and spring in the three locations was significantly higher than summer and autumn seasons. Increasing and decreasing of sea level trends with respect to time were also observed. Inter-decadal variations in sea level including a fairly regular quasi 2.5–2.7 year oscillation in all seasons were detected, although its amplitude varied among different cycles. Studying the cyclicity in the hydroclimatic record can resolve some of the complexities of the hydroclimate system. The sign of Quasi Biennial Oscillation, El Niño Southern Oscillation and sunspots events may have an important influence in sea level variations of the Red Sea. 相似文献
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8.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
9.
中国沿岸近期多年月平均海面随机动态分析 总被引：3，自引：1，他引：2
本文以最大熵谱分析了中国沿岸15个站1971～1995年月平均海面序列,得出中国沿岸月平均海面的主要振动为年振动和半年振动,而主要低频周期在中国北方各站为18.6a,从长途至厦门各站为9a左右.然后以随机动态拟合分析方法计算出中国沿岸月平均海面相对上升速率范围为(1.07±0.83)mm/a,并同时指出该方法计算出的上升速率受时段长度及低频周期的影响.最后,给出了中国沿岸月平均海面变异的时空分布,并说明了厄尔尼诺现象主要影响中国南部沿海的月均海面. 相似文献
10.
Shigehisa Nakamura 《Marine Geodesy》2013,36(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
11.
On the basis of the analyses of significant periods for the sea level observation data taken from recent several decades at 12 tide stations, the monthly mean sea level observations are fitted by a model of linear trend of sea level change superimposed with several variations of different fixed periods. The trends of sea level relative changes and their errors are estimated by the LS method. The results are reduced to the isostatic datum proposed and established in the paper (Huang et al. , 1991, Seismology and Geology , 1, 1-15). The trends of sea level changes in the near future along the coast of China are studied. It is pointed out that the general trend of the sea level change along the coast of China is going up slowly and the rate of the change is not the same in different segments of the coasts. In a few segments, the sea level is even relatively going down. The numerical results given in this paper provide a basis for the predictions of the future sea level changes and their effects. 相似文献
12.
采用经验模态分解法对太平洋沿岸验潮站的月平均海平面资料进行处理,结合T/P高度计资料、Church(2004)重构SSH资料、Ishii(2005)月均海温资料,研究太平洋海平面年际、年代际变化以及资料长度内海平面变化趋势。太平洋沿岸海平面总体呈上升趋势,平均上升速率为1.4 mm/a,趋势项分布有明显的区域性和纬度特征。ENSO对太平洋地区海平面年际变化有显著影响,海平面年际变化与Nino3指数在西(东)太平洋为负(正)相关,海平面年际变化与Nino3指数的相关性在热带太平洋最大,并随着纬度升高相关性减弱,且不同地区年际变化有滞后ENSO时间不等的最大相关。海平面年际变化与PDO指数在西(东)太平洋为负(正)相关,海平面与PDO的相关性分布有区域性和随时间演变特征。年代际变化对目前使用卫星高度计资料分析海平面长期趋势项的预测有直接影响,可能完全掩盖海平面长期变化趋势。 相似文献
13.
Response of the low-frequency fluctuations of sea level to atmospheric forcing along the coasts of the Huanghai Sea and the East China Sea 总被引：1，自引：0，他引：1
In this paper, the low-frequency fluctuations of sea level and their relationship to atmospheric forcing along the coasts of the Huanghai Sea and the East China Sea are studied. Spectrum analyses are made for the time series of daily mean sea level, atmospheric pressure and wind stress at seven coastal stations. It is found that at all the stations, the main part of the energy of the sea level fluctuations, within the (2-60)-day period, is concentrated on the (12-60)-day period band and that an obvious spectral peak appears at the 3-day period. Along the coast of the Huanghai Sea, variations in the sea level are greater in winter than in summer. In winter, along the coasts of the Huanghai Sea and the East China Sea there is a kind of sea level fluctuations propagating southwards. Among the many factors causing sea level variation, the most obvious one is atmospheric pressure, followed next by the alongshore wind stress. 相似文献
14.
This paper deals with the variations of the monthly mean sea level of the seas near China. The distribution charts of mean, sea level in winter and in summer are given. The monthly mean sea level variations are mainly caused by monsoon, sea currents and the fluctuation of atmosphen'c pressure. The annual range of monthly mean sea level is 50 -70 cm in the northern part of the seas near China, and 20-40 cm in the southern part. The variation period of the monthly mean sea level of the seas near China is principally annual one. 相似文献
15.
Calibrations between sodium （Na^＋） concentrations from a Mt. Logan ice core and sea level pressure （SLP） series show that Na^＋ concentrations are closely correlated with the autumn-time （September-October-November） Aleutian low （AleuLow）. A deepening of the AleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. The Mt. Logan Na^＋ record is used to develop a 292 a （1688-1979） reconstruction of the AleuLow revealing a dramatic intensification of atmospheric circulation over the North Pacific region since the 20th century. Mean SLP of the AleuLow was about 1 hPa lower during the 20th century than during prior periods. The strongest deepening of the AleuLow appeared in the 1950s. Significant correlations are also found between the Mt. Logan AleuLow proxy series and the Pacific decadal oscillation （PDO） and Pacific circulation （PC） index during the 20th century. Evolutionary spectral analysis of the proxy record shows significant periodicities from 15 to 30 a consistent with PDO fluctuations and the bidecadal oscillation of North Pacific atmosphere-ocean circulation. A period of 11 a in the AleuLow record may be associated with the Schwabe 11-a cycle of sunspot activity. Additional longer ice core records from this region will aid in the efforts to further understand the climatic change over the North Pacific region. 相似文献
16.
《African Journal of Marine Science》2013,35(1):195-203
Principal components analysis was used to examine monthly data on sea level obtained from tide-gauge records from the west coast of southern Africa over the period 1957—1975. After a simple correction had removed the effect of local atmospheric pressure, this statistical analysis revealed the structure of nearshore ocean variability over time periods of months to years. The first principal component, accounting for over 55 per cent of the variability in monthly mean sea level, was a near uniform rise and fall everywhere along the west coast of southern Africa. The spectrum of this large-scale structure showed a strong interannual trend, which correlated well with long-term trends of temperature anomaly over the entire South-East Atlantic, and a high-frequency term, which could not be resolved at a time period of one month. The second principal component showed the contrasting response of the northern and southern sites on a seasonal scale, and it could be correlated with seasonal wind data. These results compared well with similar analysis carried out in the North Pacific Ocean. 相似文献
17.
The pole tide, which is driven by the Chandler Wobble, has a period of about 14 months and typical amplitudes in the World Ocean of ～0.5 cm. However, in the Baltic Sea the pole tide is anomalously high. To examine this effect we used long-term hourly sea level records from 23 tide gauges and monthly records from 64 stations. The lengths of the series were up to 123 years for hourly records and 211 years for monthly records. High-resolution spectra revealed a cluster of neighboring peaks with periods from 410 to 440 days. The results of spectral analysis were applied to estimate the integral amplitudes of pole tides from all available tide gauges along the coast of the Baltic Sea. The height of the pole tide was found to gradually increase from the entrance (Danish Straits, 1.5–2 cm) to the northeast end of the sea. The largest amplitudes—up to 4.5–7 cm—were observed in the heads of the Gulf of Finland and the Gulf of Bothnia. Significant temporal fluctuations in amplitudes and periods of the pole tide were observed during the 19th and 20th centuries. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
20.
Shigehisa Nakamura 《Marine Geodesy》2013,36(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献