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1.
Rayleigh面波地震背景噪声成像技术已被成功运用到全球范围不同尺度的地球内部结构的研究中,并以背景噪声场是时空均匀分布为前提假设.然而真实的噪声源分布的时空非均匀性将导致经验格林函数提取存在偏差,最终影响噪声成像结果的精准性.近年来,噪声源分布特征研究逐步成为提高噪声成像精准度、深化地震背景噪声成像的关键问题.本文利用频率-波束域分析法对中国西北地区的一个大孔径台阵(WuTan Array,简称WTA)在2014全年的垂直分量连续记录做了聚束分析,研究了Rayleigh波噪声源分布特征.结果显示:WTA台阵成功探测到了10～20s周期范围的来自于全球不同方位的Rayleigh波噪声信号,其源区分布具有明显的季节变化特征:冬季集中分布在北大西洋方位,而夏季则转为印度洋方位噪声信号最强.此外,Rayleigh波噪声源区空间分布还表现出一定的频率依赖性,即在较低频段(0.0488～0.0635Hz)在北大西洋、北太平洋、印度洋及西太平洋四个方位均有分布;而在频率较高频段(0.0928～0.1025Hz)则集中分布于西太平洋方位.Rayleigh波噪声源时空分布特征和频率依赖性与海洋活动本身的季节性变化和频谱特征有关.并初步推测本文所观测到的Rayleigh波是由加剧的海浪运动直接作用于海岸、大陆架或海底而激发产生的第一类地脉动噪声信号. 相似文献
2.
地震背景噪声特性及噪声源的分布研究逐渐成为深化背景噪声层析成像的关键问题.海岛地区由于特殊的地理位置，其背景噪声具有相对独特的特征.地脉动（约0.003~1 Hz）是地震背景噪声中能量最强的分量，其激发与特性被认为与海浪运动和固体地球之间的相互作用有关，但海岛地区地脉动特征与海洋波浪场之间的关系尚未被充分研究.本文利用西北太平洋海岛地震台站的连续记录数据、波浪浮标的实测数据以及WAVEWATCH-Ⅲ海浪模式的数值模拟结果，通过地震学和海洋学的交叉，分析海岛地区地脉动信号的时频特性及其与海洋波浪场之间的相关性，从海洋学角度对地脉动信号的特征及激发进行探讨与解释.结果表明，海岛地区地脉动信号相对于内陆地区更强，并具有明显且稳定的季节性变化特征：高频地脉动信号（0.12~0.32 Hz）在夏秋季节（5月-10月）相对较弱，而在冬春季节（11月-次年4月）相对较强，与北半球海洋活动季节性变化相一致.此外，海岛地区地脉动主要受周边海域波浪场影响，与周边海域波浪能功率密度及实测和数值模拟所得的有效波高均具有很好的互相关性.该研究结果同时表明可进一步发展利用地脉动观测数据反演海表波浪场的可能，为海洋科学研究中海表波浪场连续观测数据的获取提供地震学上的支持. 相似文献
3.
南极冰盖冰雪质量变化反映了全球气候变化,并且直接影响着全球海平面变化.ICESat测高卫星的主要任务之一就是要确定南北两极冰盖的质量变化情况并评估其对全球海平面变化的影响.本文利用2003年10月至2008年12月的ICESat测高数据,针对南极DEM分辨率有限的特殊性,通过求解坡度改正值,解决重复轨道地面脚点不重合的问题,计算了南极大陆(86°S以北区域,后文所述南极冰盖均不包括86°S以南区域)在这5年里的冰雪质量变化情况,得到东南极冰盖的质量变化为-18±20Gt/a,西南极-26±6Gt/a,南极冰盖的冰雪质量变化为-44±21Gt/a,对全球海平面上升的影响约为0.12mm·a~(-1).解算结果表明,南极冰盖质量亏损主要集中在西南极阿蒙森海岸附近冰川以及东南极波因塞特角区域. 相似文献
4.
Changes of mean annual net accumulation at the surface on the grounded ice sheets of East Antarctica, West Antarctica and Greenland in response to variations in sea ice extent are estimated using grid-point values 100 km apart. The data bases are assembled principally by bilinear interpolation of remotely sensed brightness temperature (Nimbus-5 ESMR, Nimbus-7 SMMR), surface temperature (Nimbus-7 THIR), and surface elevation (ERS-1 radar altimeter). These data, complemented by field data where remotely sensed data are not available, are used in multivariate analyses in which mean annual accumulation (derived from firn emissivity) is the dependent variable; the independent variables are latitude, surface elevation, mean annual surface temperature, and mean annual distance to open ocean (as a source of energy and moisture). The last is the shortest distance measured between a grid point and the mean annual position of the 10% sea ice concentration boundary, and is used as an index of changes in sea ice extent as well as of mean concentration. Stepwise correlation analyses indicate that variations in sea ice extent of ± 50 km would lead to changes in accumulation inversely of ± 4% on East Antarctica, ± 10% on West Antarctica, and ±4% on Greenland. These results are compared with those obtained in a previous study using visually interpolated values from contoured compilations of field data; they substantiate the findings for the Antarctic ice sheets (±4% on East Antarctica, ±9% in West Antarctica), and suggest a reduction by one half of the probable change of accumulation on Greenland (from ±8%). The results also suggest a reduction of the combined contribution to sea level variability to ±0.19 mm a-1 (from ±0.22 mm a-1). 相似文献
5.
Seasonal changes of the primary and secondary microseisms were analysed in the wavefield of the ambient noise recorded during the entire 2014 at the “13 BB star” array located in northern Poland, composed of thirteen, symmetrically arranged, broadband seismic stations. To that, spectral analysis, seismic interferometry, surface scalar wind speed distribution, and beamforming were used. Spectral analysis allowed to observe that a splitting of the secondary microseism peak was present in winter and autumn, and that the primary microseism peak was visible in spring, summer and autumn. Using seismic interferometry, the long-term characteristics of the noise wavefield were recognized. The seasonal variations of the secondary microseism source were described by means of the analysis of the surface scalar wind speed for each month. The splitting of the secondary peak was attributed to the interaction of a strong wind blowing from the North Sea with a weak wind blowing from the Baltic Sea. The seasonal variations of the primary microseism peak were characterized through the frequency-domain beamforming. The peak was identified during spring, summer and autumn, when the generated wavefield was coming from the Baltic Sea. The velocity of the wavefield was evaluated within the 2.0–5.0 km/s range. The described mechanism of generation of the microseisms, based on the interaction of the nearby winds, was found to be consistent with the models reported in the literature. 相似文献
6.
鉴于卫星测高技术在南极周边海域会受到海面浮冰影响,且在利用测高序列分析海平面周期性动态变化时还会受到潮汐周期混叠效应的影响,为此,本文开展了基于GPS和验潮数据联合的南极大陆附近海域从1994-2014年间海平面的绝对变化研究.研究结果显示：在围绕南极大陆及附近海域的15个验潮站中,海平面绝对变化速度最大的是Diego Ramirez验潮站,达到11.10±0.04 mm·a-1;在西南极南极半岛的德雷克海峡,海平面变化最为活跃,变化均值在8.31±0.05 mm·a-1;在东南极,从Syowa站依次到Casey站,海平面的绝对变化速度相对平稳,四个潮位站海平面变化均值为3.35±0.04 mm·a-1;在罗斯冰架右下侧的罗斯岛附近,由于冰川崩解入海导致Scott Base站处的海平面上升速度较快,达到了9.61±0.07 mm·a-1.综合15个验潮站计算结果可得南极半岛德雷克海峡和罗斯岛附近海域,海平面绝对变化速度要高于同期南大洋海平面绝对变化速度,而东南极4个潮位站海平面绝对变化均值则与其相当.这也进一步反映了南极不同海域间海平面变化的差异性,相比较于对南大洋海平面变化的一个整体研究,分区研究海平面变化更具针对性,能更好地了解南极不同区域冰盖、冰架崩解和消融的情况. 相似文献
7.
Thirteen years of GRACE data provide an excellent picture of the current mass changes of Greenland and Antarctica, with mass loss in the GRACE period 2002–2015 amounting to 265 ± 25 GT/year for Greenland (including peripheral ice caps), and 95 ± 50 GT/year for Antarctica, corresponding to 0.72 and 0.26 mm/year average global sea level change. A significant acceleration in mass loss rate is found, especially for Antarctica, while Greenland mass loss, after a corresponding acceleration period, and a record mass loss in the summer of 2012, has seen a slight decrease in short-term mass loss trend. The yearly mass balance estimates, based on point mass inversion methods, have relatively large errors, both due to uncertainties in the glacial isostatic adjustment processes, especially for Antarctica, leakage from unmodelled ocean mass changes, and (for Greenland) difficulties in separating mass signals from the Greenland ice sheet and the adjacent Canadian ice caps. The limited resolution of GRACE affects the uncertainty of total mass loss to a smaller degree; we illustrate the “real” sources of mass changes by including satellite altimetry elevation change results in a joint inversion with GRACE, showing that mass change occurs primarily associated with major outlet glaciers, as well as a narrow coastal band. For Antarctica, the primary changes are associated with the major outlet glaciers in West Antarctica (Pine Island and Thwaites Glacier systems), as well as on the Antarctic Peninsula, where major glacier accelerations have been observed after the 2002 collapse of the Larsen B Ice Shelf. 相似文献
8.
0.003~1 Hz频段的地脉动主要来源于海浪运动与固体地球的耦合作用,台风引起的强烈海浪运动往往可使地脉动能量显著增强.由于涉及大气-海洋-固体地球三个圈层之间的复杂动量传递与耦合过程,迄今为止,关于台风激发地脉动的具体源区位置及激发机制尚存在争议.本文选取日本、中国东南沿海及台湾地区的地震台站波形连续记录,研究了2008年台风"森拉克"和"黑格比"激发地脉动的时频特征,开展相应数值模拟,并与观测数据进行了对比分析研究.结果表明台风激发第二类地脉动存在两种主要模式:(1)近岸源区激发,即台风引起波浪入射至海岸反射并与后续来波相互作用形成驻波作用于海底而激发;(2)台风中心附近源区激发,即台风中心移动过程中不同时期激发的同频率波浪相向传播、相互作用产生驻波作用于海底而激发,源区位置主要集中于台风中心左后方.此外,结合波浪再分析数据、台风风场特征,我们进一步对第二类地脉动激发过程中的影响因素进行了分析,发现:第一种模式激发的地脉动与近岸源区波浪场强度、观测点至源区距离及台风中心至海岸线距离等因素相关;而第二种模式激发的地脉动则主要受台风中心附近波浪场的频率成分与传播方向影响. 相似文献
9.
选取四川省数字测震台网2015年1月1日至2018年12月31日期间60个固定台站的三分量连续波形记录,计算了台站噪声加速度功率谱密度及相应的概率密度函数分布,统计了不同频率下的噪声功率谱密度值分布,对不同区域、不同频率下背景噪声水平的变化特征予以分析。结果表明:大部分地震台站的高频段噪声由于受到台站附近人为的、规律的作息生活和生产方式的影响,呈现明显的季节性变化和日变化,即夏季噪声水平升高,冬季降低,在农历春节期间达到全年最低值,地理空间分布特征不明显;第二类地脉动冬季噪声水平升高,夏季降低,季节性变化明显,平均变化为1—5 dB,且冬季峰值出现的频率向长周期方向移动1—2 s,呈现明显的地理空间分布特征,川东地区平均噪声水平最高,攀西地区次之,川西高原最低;与第二类地脉动相比,第一类地脉动观测到的噪声能量较弱,季节性变化不明显,地理空间分布的噪声水平差异明显减小;在20 s以上的长周期部分,台站噪声未呈明显的季节性和地理空间分布差异。此外,将地震计安置在山洞和井下,可以有效地降低台站周围干扰源、温度和压强对高频段和长周期观测的影响,噪声水平低于地表安装方式。 相似文献
10.
Vivien Gornitz 《地球表面变化过程与地形》1995,20(1):7-20
Global mean sea level is a potentially sensitive indicator of climate change. Global warming will contribute to worldwide sea-level rise (SLR) from thermal expansion of ocean water, melting of mountain glaciers and polar ice sheets. A number of studies, mostly using tide-gauge data from the Permanent Service for Mean Sea Level, Bidston Observatory, England, have obtained rates of global SLR within the last 100 years that range between 0·3 and 3 mm yr?1, with most values concentrated between 1 and 2 mm yr?1. However, the reliability of these results has been questioned because of problems with data quality and physical processes that introduce a high level of spatial and temporal variability. Sources of uncertainty in the sea-level data include variations in winds, ocean currents, river runoff, vertical earth movements, and geographically uneven distribution of long-term records. Crustal motions introduce a major source of error. To a large extent, these can be filtered by employing palaeo-sea-level proxies, and geophysical modelling to remove glacio-isostatic changes. Ultimately, satellite geodesy will help resolve the inherent ambiguity between the land and ocean level changes recorded by tide gauges. Future sea level is expected to rise by ～ 1 m, with a ‘best-guess’ value of 48 cm by the year 2100. Such rates represent an acceleration of four to seven times over present rates. Local land subsidence could substantially increase the apparent SLR. For example, Louisiana is currently experiencing SLR trends nearly 10 times the global mean rate. These recently reduced SLR estimates are based on climate models that predict a zero to negative contribution to SLR from Antarctica. Most global climate models (GCMs) indicate an ice accumulation over Antarctica, because in a warmer world, precipitation will exceed ablation/snow-melt. However, the impacts of attritional processes, such as thinning of the ice shelves, have been downplayed according to some experts. Furthermore, not all climate models are in agreement. Opposite conclusions may be drawn from the results of other GCMs. In addition, the West Antarctic Ice Sheet is potentially subject to dynamic and volcanic instabilities that are difficult to predict. Because of the great uncertainty in SLR projections, careful monitoring of future sea-level trends by upgraded tide-gauge networks and satellite geodesy will become essential. Finally, because of the high spatial variability in crustal subsidence rates, wave climates and tidal regimes, it will be the set of local conditions (especially the relative sea-level rise), rather than a single global mean sea-level trend, that will determine each locality's vulnerability to future SLR. 相似文献
11.
C. J. van der Veen 《Surveys in Geophysics》1987,9(3-4):389-418
Through the use of fossil fuels as an energy source, mankind is slowly changing the constitution of the atmosphere. The emission of CO2 and other greenhouse gases changes the radiative properties of the earth/atmosphere system, and as a result climate is expected to become warmer. As a starting point for the sea-level rise scenario discussed here it is assumed that the globally-averaged increase of surface air temperatures will amount to 2 to 4°C in the second half of the next century (i.e. around 2085 AD). One of the consequences of this warming is an accelerated rise in sea level, caused by thermal expansion of ocean water and further retreat of mountain glaciers. The Greenland Ice Sheet will also decrease in size, but on the other hand, Antarctica is expected to grow slightly due to increased snowfall. Taken together, the projection for future sea level presented here suggest that by 2085 AD, global sea-level stand will be 28–66 cm higher than the present level, which implies a rate of sea-level rise of about 2 to 4 times that observed during the last 100 yr. Our scenario does not include a contribution resulting from the possible collapse of the West Antarctic Ice Sheet. If this collapse is indeed likely to occur after the major peripheral ice shelves have thinned considerably, the effects on sea level will be small in the coming 100 yr. First, the oceans surrounding Antarctica must have warmed sufficiently to reduce the winter sea-ice extent to allow circumpolar deep water to penetrate into the sub-shelf cavities, thus increasing basal melt rates on the ice shelves. Of course, on longer time scales, West Antarctica could become the major contributor to rising sea level. 相似文献
12.
为了区分汶川大地震的震前扰动现象中的台风因素和非台风因素,本文研究了中国大陆宽带地震仪在汶川大地震前记录到的异常扰动信号的时频特征.研究结果表明汶川大地震的震前扰动主要由两种扰动构成,二者动态特征完全不同.其中优势频率为0.2～0.25 Hz的扰动主要与台风Rammasun有关.这种台风扰动在沿海地区较强,在内陆地区较弱,其震动源在靠近台风运动路径的海底.另一种优势频率为0.1～0.18 Hz的扰动与台风无关,这种非台风扰动在地震发生前约10 h突然急剧增强,其最大值出现在地震爆发时刻.非台风扰动在靠近震中的地区较强,在沿海和西部地区较弱.震源扰动扫描算法计算初步定位的结果显示其震动源不在海底,而是分散在震中附近的内陆地区.汶川大地震前的非台风扰动是否与汶川大地震有关,值得进行更深入的研究. 相似文献
13.
归纳总结了在南极开展地震学研究中的各种主要方法及其研究成果,较全面地介绍了南极地震学研究的现状与进展．首先对南极地震活动性作了简单的介绍,然后分别介绍了利用面波和体波研究地壳上地幔结构的主要成果,最后从地震各向异性的角度归纳介绍了南极大陆部分区域面波方位各向异性及剪切波分裂研究的主要成果．研究表明,南极大陆地震活动性较低、地震强度较小,仅在横贯南极山脉区域、维多利亚地、阿黛利地、威尔克斯地等有较明显的地震活动; 横贯南极山脉将南极大陆分为东南极和西南极两个不同的地质构造区域,东南极地壳和上地幔地震波速度偏高,西南极则偏低;上地幔各向异性较为明显并普遍存在,且西南极各向异性强度稍高于东南极克拉通． 相似文献
14.
本文主要利用时频分析法，基于2016年以来山东省泰安台重力仪及宽频带地震仪观测到的资料，对风暴天气和台风天气引起的微震现象进行研究. 结果表明:这两种天气过程产生的微震信号的频率基本分布在2—20 s之间，能量集中在5—7 s，15 s附近存在一个能量平稳加强的频段；风暴天气产生的微震信号具有由高频向低频演化的动态特征；两种天气条件下产生的微震信号均具有连续、高频及持续时间长的性质，反映了微震信号激发源的移动特征。 结合泰安台微震与风暴和台风天气的一一对应情况，认为微震是一种与近海风暴或远海台风活动有关的微震动过程，而不是与地震有关的前兆异常。 相似文献
15.
利用5年的GRACE重力数据,计算了南极1°×1°等效水量时间序列,得到每个格网的趋势项,结果表明在西南极Amundsen区域有明显的负增长,超过-80 mm/a,南极半岛存在着负增长,东南极Enderby Land地区质量增长;计算得到2002年7月到2007年9月南极、东南极和西南极冰盖的等效体积变化分别为-78±37 km3/a,-3±46 km3/a和-75±50 km3/a,对应海平面变化的贡献为0.21±0.1 mm/a,0.008±0.127 mm/a和0.2±0.14 mm/a.该结果与国际最新研究结果一致.同时发现冰后回弹是影响利用GRACE研究南极冰盖质量变化的关键因素. 相似文献
16.
本文基于CSR最新公布的GRACE RL06版本数据,采用Slepian空域反演法估算了南极冰盖27个流域的质量变化.Slepian空域反演法结合了Slepian空间谱集中法和空域反演法的技术优势,能够有效降低GRACE在小区域反演时信号出现的严重泄漏和衰减,进而精确获得南极冰盖在每个流域的质量变化.相对于GRACE RL05版本数据,RL06在条带误差的控制上要更加优化,获得的南极冰盖质量变化时间序列也更加平滑,但在趋势估算上差别并不明显(小于10Gt/a).本文的估算结果显示:在2002年4月至2016年8月期间,整个南极冰盖质量变化速率为-118.6±16.3Gt/a,其中西南极为-142.4±10.5Gt/a,南极半岛为-29.2±2.1Gt/a,东南极则为52.9±8.6Gt/a.南极冰盖损失最大的区域集中在西南极Amundsen Sea Embayment(流域20-23),该地区质量变化速率为-203.5±4.1Gt/a,其次为南极半岛(流域24-27)以及东南极Victoria-Wilkes Land(流域13-15),质量变化速率分别为-29.2±2.1Gt/a和-19.0±4.7Gt/a,其中Amundsen Sea Embayment和南极半岛南部两个地区的冰排放呈现加速状态.南极冰盖质量显著增加的区域主要有西南极的Ellsworth Land(流域1)和Siple Coast(流域18和19)以及东南极的Coats-Queen Maud-Enderby Land(流域3-8),三个地区质量变化速率分别为17.2±2.4Gt/a、43.9±1.9Gt/a和62.7±3.8Gt/a,质量增加大多来自降雪累积,比如:Coats-Queen Maud-Enderby Land在2009年和2011年发生的大规模降雪事件,但也有来自冰川的增厚,如:Siple Coast地区Kamb冰流的持续加厚.此外,对GRACE估算的南极冰盖质量变化年际信号进行初步分析发现,GRACE年际信号与气候模型估算的冰盖表面质量平衡年际信号存在显著的线性相关关系,但与主要影响南极气候年际变化的气候事件之间却不存在线性相关关系,这说明南极冰盖质量变化的年际信号主要受冰盖表面质量平衡的支配,而气候事件对冰盖表面质量平衡的影响可能是复杂的非线性耦合过程. 相似文献
17.
2002年发射的GRACE重力卫星为南极冰盖质量平衡提供了一种新的测量方式,但由于南极GIA模型的不确定较大,进而影响GRACE结果的可靠性.本文联合2003—2009年的GRACE和ICESat等数据实现了南极GIA信号的分离,联合方法所分离的GIA不依赖于不确定性很大的冰负荷等假设模型,而是直接基于卫星观测数据估算而来的,具有更大的可靠性.在分离过程中,本文提出了冰流速度加权改正法和GPS球谐拟合改正法对GIA结果进行精化,同时引入了南极GPS观测站的位移数据对分离的GIA进行详细的评估和验证,GPS验证表明经过冰流速度加权和GPS球谐拟合双改正后的GIA结果精度明显得到提高.最后本文利用所分离的GIA对GRACE和ICESat结果进行了改正,得到2003—2009年南极冰盖质量变化的趋势为-66.7±54.5 Gt/a(GRACE)和-77.2±21.5Gt/a(ICESat),相比采用其他的GIA模型,本文的GIA结果使GRACE和ICESat这两种不同观测技术得到的南极冰盖质量变化结果更加趋于一致. 相似文献
18.
W. P. Budgell 《Ocean Dynamics》2005,55(3-4):370-387
A dynamic–thermodynamic sea ice model has been coupled to a three-dimensional ocean general circulation model for the purpose of conducting ocean climate dynamical downscaling experiments for the Barents Sea region. To assess model performance and suitability for such an application, the coupled model has been used to conduct a hindcast for the period 1990–2002. A comparison with available observations shows that the model successfully tracks seasonal and inter-annual variability in the ocean temperature field and that the simulated horizontal and vertical distribution of temperature are in good agreement with observations. The model results follow the seasonal and inter-annual variability in sea ice cover in the region, with the exception that the model results show too much ice melting in the northern Barents Sea during summer. The spatial distribution of the winter simulated sea ice cover is in close agreement with observations. Modelled temperatures and ice concentrations in the central Barents Sea are biased too high and too low, respectively. The probable cause is too high inflow of Atlantic Water into the Barents. The seasonal and inter-annual fluctuations in temperature and sea ice cover in the central Barents are, however, in excellent agreement with observations. Salt release during the freezing process in the numerical simulation exhibits considerable inter-annual variability and tends to vary in an opposite manner to the net inflow volume flux at the western entrance of the Barents Sea. Overall, the model produces realistic ice-ocean seasonal and inter-annual variability and should prove to be a useful tool for dynamical downscaling applications. 相似文献
19.
本文介绍了应用电磁反馈零位检测技术改装的重力仪进行高频信息的观测。阐述重力仪高频信息频谱分布特征、数据采集、数字计算和随机信息的处理方法。利用高频信息可以很好地观测和研究地脉动,给出北京香山地震台利用重力仪高频信息观测所得的地脉动功率谱。分析了地脉动特征及其与台风过程的关系;讨论了某些大地震前所出现的地脉动异常现象。得出北京地区正常地脉动频率分布范围为0.13-0.32Hz,优势频率为0.2Hz,相应的卓越周期为5s的脉动频率异常,也可能在地脉动的正常频率处（0.2Hz左右）,出现幅度很大的脉动幅度异常,后者又往往与台风引起的幅度异常相混淆。 相似文献
20.
Seasonal variations of the Hawaiian Lee Countercurrent induced by the meridional migration of the trade winds 总被引：1，自引：0，他引：1
Hideharu Sasaki Shang-Ping Xie Bunmei Taguchi Masami Nonaka Yukio Masumoto 《Ocean Dynamics》2010,60(3):705-715
Seasonal variations of the Hawaiian Lee Countercurrent (HLCC) are investigated using satellite observations of sea surface
height and wind stress as well as eddy-resolving ocean model simulations. The HLCC is strong from summer to winter and weak
in spring between the dateline and the Hawaiian Islands. In response to the seasonal migration of the northeast trade winds
in the meridional direction, the wind curl dipole lee of Hawaii varies in strength, exciting westward-propagating Rossby waves.
The analyses of both observations and simulations show that the propagation of Rossby waves south of the HLCC, driven by the
southern pole of the wind curl dipole in the lee of the islands, contributes the most to the seasonal variations of the HLCC.
Unlike the wind-driven seasonal variations, our analysis suggests that other mechanisms such as mode water intrusion or air–sea
interaction may cause the interannual variations of the HLCC. 相似文献