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1.
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   

2.
3.
基于1988-2017年高分辨率的欧洲中尺度天气预报中心再分析数据,本文对中国近海的低空大气波导进行了统计分析.结果表明:该海域整体大气波导概率为22%,其中悬空波导占60%以上;春季最容易发生大气波导,其次是夏季、秋季和冬季.区域时空分布上,中国近海大气波导特征具有明显的月变化和区域分布特征.大气波导发生概率北部海域...  相似文献   

4.
The long-term variation and seasonal variation of sea level have a notable effect on the calculation of engineering water level. Such an effect is first analyzed in this paper. The maximal amplitude of inter-annual anomaly of monthly mean sea level along the China coast is larger than 60 cm. Both the storm surge disaster and cold wave disaster are seasonal disasters in various regions, so the water level corresponding to the 1% of the cumulative frequency in the cumulative frequency curve of hourly water level data for different seasons in various sea areas is different from design water level, for example, the difference between them reaches maximum in June, July and August for northern sea area, and maximum in September, October and November for Southern China Sea. The hourly water level data of 19 gauge stations along the China coast are analyzed. Firstly, the annual mean sea level for every station is obtained; secondly, linear chan ging rates of annual mean sea level are obtained with the stochasti  相似文献   

5.
This is a review of sea level data performed at three selected stations (Québec-Lauzon, Harrington Harbour,and Halifax) in eastern Canada in order to investigate the seasonal trends and other long-term and short-term changes which occurred since the beginning of the 20th century. Stations situated in riverine or estuarine regions (e.g., Québec-Lauzon) are significantly affected by freshwater flow in their annual cycle of sea level changes and exhibit a definite maximum in spring and minimum in autumn-winter. Other stations situated in the eastern half of the Gulf of St. Lawrence (e.g., Harrington Harbour) or near the open Atlantic coast (Halifax) mainly follow the general cycle of subarctic regions, with lows in spring-summer and highs in autumn-winter. Such seasonal variations appear to be related to the atmospheric pressure and baroclinic current variations. Secular trends in mean sea level in eastern Canadian waterbodies show a mean rise of about 2.56 mm/yr -1 due to tectonic motions, that is, land subsidence. At several stations in eastern Canada, evidence is found for the influence of the nodal tide (18.6 years), the sunspot cycle (10.8 years), the lunar perigee (8.47 years), the pole tide (14.5 months), the annual cycle (12 months), and semiannual tidal cycle (6 months) in sea level records. Beside long-term oscillations with periods of more than one year, evidence is found for high energetic semidiurnal and diurnal tides where they contribute largely (from 90-95%) to short term variability of sea level. In the residual signal (variations of sea level--tidal variations), short-term variations between 2 to 30 days can be attributed to meterological forcing (atmospheric pressure and winds), longitudinal seiches (2-10 h), atmospheric tides (12 h and 24 h) and inertial oscillations (16-18 h). A regressive model showed that the water discharge from the St. Lawrence River contributes 29% to the monthly residual sea level at Québec-Lauzon. The atmospheric pressure and winds contribute respectively 8.1% and 8.9% at this station. They contribute 52.1% and 7.7% at Harrington Harbour and 41.8% and 14.3% at Halifax. The regression coefficients of residual sea level on atmospheric pressure are respectively estimated to be -1.507 cm. ( hPa ) -1 ( - 0.345 cm. ( hPa ) -1 ), -0.776 cm. ( hPa ) -1 ( - 0.112 cm. ( hPa ) -1 ) and -0.825 cm. ( hPa ) -1 ( - 0.008 cm. ( hPa ) -1 ) at the three stations. Compared to the coefficient of the inverted barometer, estimated to be -1 cm. ( hPa ) -1 , these effects of the atmospheric pressure on sea level variations seem to be amplified at Que´bec-Lauzon by the wind effects (and water discharge) while they are reduced at Harrington Harbour and Halifax.  相似文献   

6.
本文通过对中国沿海25个观测站水位资料的分析,初步探讨了中国沿海1980-2012年增减水的变化特征及与海平面变化的关系。结果表明:(1)中国沿海增减水的季节变化特征明显,相邻站由于受到的气象状况相同,其沿海增减水变化的过程相近,但是变化幅度存在较大差异。从空间分布看,沿海增减水的变化幅度呈现中间大南北小的区域特征,自长江口至广东沿海,增减水的年变化幅度最大,年变幅平均为5.0~7.5 cm;南海周边及北部湾沿海,增减水的年变化幅度次之,年变幅平均为4.0~5.5 cm;自渤海至黄海沿海,增减水的年变化幅度较小,年变幅平均为3.3~3.5 cm。(2)从时间变化看,1980-2012年中国沿海年平均增减水长期基本没有趋势性变化,但明显存在2至5年的周期性变化信号,该信号的震荡幅度为0.1 cm。经过高频滤波后,对沿海月平均增减水序列与Niño3.4指数进行相关性分析,相关系数为-0.5,该相关系数通过了显著性检验,说明中国沿海的增减水变化与ENSO事件呈现负相关关系。(3)中国沿海增减水的长期变化及空间分布特征均与海平面变化不同。1980-2012年,中国沿海海平面的上升速率为2.9 mm/a,而增减水长期基本无趋势性变化;另外,其季节变化与海平面的季节变化从时间和区域上均不存在一致性。(4)但是,短期海平面的变化与增减水有关,并且增减水对短期海平面的贡献根据其具体情况而定,增水幅度大且持续时间长的过程对短期海平面有抬升作用,其贡献率最大可达65%;反之,减水幅度大且持续时间长的过程则对短期海平面有降低的作用。  相似文献   

7.
应用ROMS数值模式配置基本实验模拟了2004年到2006年中国东部海域海平面的季节变化。模拟结果与TOPEX/Poseidon(T/P)卫星高度计观测结果基本一致,海平面年较差从中国沿岸到黑潮路径逐渐变小。将数值模式的风应力项去掉,配置对比实验。与基本实验结果对比发现,对比实验海平面仍然具有季节变化,但是闽浙沿岸和苏北沿岸海平面春夏季异常偏低、秋冬季异常偏高现象消失,中国沿岸向太平洋的海平面变化减弱。春季和秋季,渤、黄海和黑潮附近海平面异于东海的现象减弱。对比实验海平面的年较差的数值明显减小,从近岸向黑潮海平面年较差渐变的过程消失。整个渤黄海的海平面年较差近似。对比实验海平面年较差占基本实验海平面年较差比率从近岸向黑潮路径逐渐增大。  相似文献   

8.
In this paper, the relationship between the crop yield in three different regions, the northern part of China, the northeast China and Heilongjiang Province, and the monthly mean sea surface temperature (SST) in the northwest Pacific Ocean is analysed preliminarily; the time and space distribution of the sea areas with high value correlation coefficients (HVCC) between the meteorological crop yield (MY) and the monthly mean SST is given; and crop yields in these regions are simulated by the monthly mean SST. Results obtained show that the stabler relationship between the crop yield in some large regions and the monthly mean SST is presented, so that we can forecast the crop yield in these regions using the monthly mean SST of the sea areas with HVCC.  相似文献   

9.
This paper describes changes in sea level off the coast of China in history and at present. The evidence concerning low sea level during the last glacial phase, Holocene marine transgression which was discovered from sea bottom in East China Sea and China's bordering seas, and their adjacent coastal areas, where, by drilling, relic sediment, peat deposite, and mollusc shell fossils have been obtained, and their dates are deduced through measurement of radiocarbon (C14), identified that low sea level about 15000 years ago stood in the depth of 150 m below the present level in East China Sea, and that the subsequent transgression carried the sea up to the present sea level 6000 years ago, when the present China's coast and other continent's coasts were outlined. Due to a number of factors, the sea level oscillates seasonally in the border sea of China. Averagely speaking, the annual range of the seasonal changes in sea level is about 35 m off the south Zhejiang coast, where the highest value of 20 cm occurs in September, and the lowest of-15 cm occurs in March. The reason may be mainly due to the seasonal variations of climate and river run-off, as well as the Taiwan Warm Current. Similar seasonal oscillations in sea level also occur in Bohai Gulf, Yellow Sea, East China Sea and the South China Sea. The beach process of south Zhejiang is strongly affected by the seasonal oscillations in sea level. The width of beach is 4 to 6 km, the slope is approximately in 1 : 1000. If the sea level rises or falls 1 cm, the beach submergence or emergence is led to be about 10 m in width. As a result, the relative equilibrium of beach will be changed by the seasonal oscillations in sea level.  相似文献   

10.
本文根据1960—1987年我国沿岸有关测站月平均水位和海面水温资料,分析和讨论了它们的年际变化以及近期7次ENSO事件对我国沿岸表面水温和水位的影响及其机制。  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.
吕宋海峡黑潮脱落涡旋的特征分析   总被引:2,自引:0,他引:2  
涡旋脱落在西太平洋和南海的海水属性交换中起到重要作用。为研究吕宋海峡附近海域由黑潮脱落并进入南海的涡旋特征,本文采用1993—2014年法国空间局(AVISO)多卫星融合海面高度距平(SLA)和绝对动力地形(ADT)全球网格化延时数据,美国国家海洋数据中心(NODC)的WOA13年平均温盐剖面气候数据,以及1993—2010年SODA2.2.4月平均海洋同化数据集,并分析了黑潮脱落涡旋与大尺度环流的关系。结果表明:(1)暖涡脱落数量远多于冷涡数量,且脱落的冷涡绝大部分在黑潮西侧边缘生成,而脱落的暖涡则大部分在黑潮控制区生成。(2)冷涡、暖涡脱落时的平均半径、平均振幅相近,但是冷涡的平均生命、平均迁移距离约为暖涡的一半。(3)冷涡不是每年都有脱落,主要在冬季脱落;暖涡则每年均有脱落,主要发生在秋季。(4)脱落涡旋数量与脱落时的黑潮路径类型相关。(5)脱落涡旋的平均西行速度为5.8cm/s,与斜压第一模态长Rossby波波速及大尺度环流的西向平流流速之和相近。  相似文献   

13.
The variability of the sea surface temperature(SST) in the China seas has been studied in seasonal,interannual and interdecadal scales based on the monthly data of HadISST spanning from 1870 to 2007. The main results obtained are SST in the China offshore changes most actively at the seasonal scale with the intensity diminishing from north to south,as the temperature differences between summer and winter reaching 17 and 4 C in the northern and southern areas,respectively. Moreover,seasonal variation near the coastal regions seems relatively stronger than that far from the coastline;significant interannual variations are detected,with the largest positive anomaly occurring in 1998 in the overall area. But as far as different domains are concerned,there exists great diversity,and the difference is also found between winter and summer. Differed from the seasonal variations,where the strongest interannual variability takes place,resides to the south of that of the seasonal ones in the northern section,nevertheless in the South China Sea,the most significant interannual variability is found in the deep basin;interdecadal changes of summer,winter and annual mean SST in different domains likewise present various features. In addition,a common dominant warming in recent 20 a are found in the overall China offshore with the strongest center located in the vicinity of the Changjiang Estuary in the East China Sea,which intensifies as high as 1.3 C during the past 130 a.  相似文献   

14.
应用海洋表层水温资料(COADS资料),分析研究了对全球气候有重要影响的热带西太平洋、印度洋海洋表层水温的年变化和年际变化的特性,探讨了与ENSO和南极冰面积变化之间的联系。结果表明,热带西太平洋及印度洋表层水温具有明显的年变化和年际变化而且它们之间存在不同的变化趋势。这种结果是两大洋的水温振荡周期不同有较大关系。热带印度洋表层水温的年际变化与E1 Ni ̄/no和La Ni ̄/na的发生年份存在较  相似文献   

15.
Reconstruction of evenly-spaced, regular time series from routine survey serial data was investigated for precise analysis of spatio-temporal variations in a temperate sea at mid-latitudes where the seasonality dominates the interannual variability. Considering that the annual range of sea surface temperature in the Yellow Sea and the northwestern East China Sea can be as large as 15–20 °C, temperature data collected bi-monthly in these temperate seas were used for the assessment of reconstruction methodology. The cubic spline interpolation with a sampling interval of 0.5 months reconstructed the regular time series closest to the in-situ measurements among various interpolation schemes. Also, two computation methods for the interannual anomaly were compared; the residual method that the long-term monthly means are subtracted from the monthly serial data and the filtering method that high-frequency variations are removed using a low-pass filter. In that the high-frequency variations in frequencies greater than 1 cycle per year are comparable in magnitude to the interannual variation, the residual method proves inadequate in the temperate sea. High-frequency noises can be effectively removed through the use of a proper low-pass filter with bell-shaped weights.  相似文献   

16.
Based on the monthly mean sea level data obtained from 3 years‘ (1999--2001) tide-gauge measurements, the annual variability of the sea level near Qingdao and Jiaozhou Bay is studied and discussed in this paper. Results show that the sea surface height at all the tide gauges becomes higher in summer than that in winter,with an obvious seasonal variability. Furthermore the sea surface height measured at a short distance outside the bay is lower than that in the bay, showing a sea surface slope downward from north to south. The reasons for the formation of the slope are explained as well. The dynamic action of the summer monsoon and the sea surface slope, and their effects on the monthly mean current are studied by means of dynamics principles. The importance of the summer monsoon and the pressure gradient generated by the sea surface slope, with their effects on the alongshore current, is pointed out and emphasized in this paper.  相似文献   

17.
中国海和泰国湾海域海平面的经向涛动   总被引:1,自引:0,他引:1  
李立 《海洋学报》2014,36(9):7-17
卫星高度计遥感海面高度距平资料(1992-2012年)的分析结果证实中国海(渤、黄、东海及南海)和泰国湾作为一个半封闭的狭长水域,其海平面存在显著的南北经向涛动。涛动呈现明显的季节性,冬季南高北低,夏季北高南低,以渤海和泰国湾的海平面高差作为涛动的测度,其多年平均波动幅度达63cm,较差超过80cm。时间序列分析显示,在季节尺度上这一涛动几乎完全受东亚季风的支配,表明东亚季风的局地强迫是造成季节涛动的主要原因。进一步的分析发现,除季节波动之外研究海域海平面的经向涛动还存在明显的年际变化。不过,与季节尺度的波动有所不同,经向涛动的年际变化不仅是东亚季风区局地作用的结果,而且与太平洋海盆尺度的大气强迫有关,其作用与季风在同一数量级。涛动的年际变化大致滞后各气候因子两个月。采用多输入线性模型做偏相关分析筛选的结果显示,除东亚季风指数之外,研究海域的海平面涛动指数主要与太平洋的南方涛动指数(SOI)和西太平洋遥相关指数(WP)相关。这表明外部强迫既来自热带,也来自中纬度。南方涛动所导致的赤道海域海平面的东西向年际涛动,以及中纬度西风急流年际波动对西北太平洋海平面的作用,都有可能导致研究海域海平面经向涛动的年际变化,其机制有待进一步探讨。  相似文献   

18.
根据美国TOGA水位中心所提供的1975—1988年水位月平均资料,分析、讨论了热带西太平洋水位的年际变化特征,特别是与ENSO事件有关的低水位现象。此外,还重点叙述了1986—1987年ENSO事件中水位沿经向和赤道剖面的变化,以及与此有关的赤道流系的变化。文中还定性地讨论了赤道开尔文波沿赤道剖面的传播特性。  相似文献   

19.
渤、黄海冰情与华北地区降水关系的分析   总被引:1,自引:0,他引:1  
本文利用北京1932~2000年逐月降水量资料、渤、黄海海冰资料及1951~2000年气候因子资料,运用相关分析方法对冬季渤、黄海冰情与华北地区降水的关系进行了探讨,研究结果表明:冰情与降水存在着条件相关,如果海冰冰级达到2.5级以上且冬季副高较前一年有增强趋势,年降水大于平均值的可能性很大。这一点是对华北降水进行预测的一个新发现,对华北年降水趋势预测有着积极的作用。根据冰情与副高可判断当年降水的趋势。  相似文献   

20.
The magnitude and geographical distribution of the error in the Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) altimetry data associated with tidal correction around Asian marginal seas has been revealed. The errors were evaluated by harmonic analysis of the AVISO corrected sea surface heights data (CorSSH). Errors of more than 15 cm of tidal correction were recognized in the western and northern parts of the Yellow Sea, Celebes Sea, Kuril Islands, and the northwestern part of the Okhotsk Sea. It was found that the CorSSH and sea level anomaly (SLA) data downloaded from the AVISO are not available for direct use in those marginal seas. To reduce the tidal correction error, the harmonic constants calculated from the latest tide model and regional tide model were applied as the tidal correction of the Altimetry data. The tidal errors in the Yellow Sea and the northwestern part of the Okhotsk Sea were reduced by approximately 20 cm and 10 cm, respectively. Root mean square differences between the harmonic constants derived from tide models and those derived from altimetry data were calculated. The root mean square differences were large in the Yellow and the Okhotsk Seas. Root sum squares for four principal tidal constituents in the Yellow and East China Seas and Okhotsk Sea were 7.72 cm and 8.36 cm, respectively.  相似文献   

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