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101.
Ocean surface waves are strongly forced by high wind conditions associated with winter storms in the Sea of Japan. They are also modulated by tides and storm surges. The effects of the variability in surface wind forcing, tides and storm surges on the waves are investigated using a wave model, a high-resolution atmospheric mesoscale model and a hydrodynamic ocean circulation model. Five month-long wave model simulations are inducted to examine the sensitivity of ocean waves to various wind forcing fields, tides and storm surges during January 1997. Compared with observed mean wave parameters, results indicate that the high frequency variability in the surface wind filed has very great effect on wave simulation. Tides and storm surges have a significant impact on the waves in nearshores of the Tsushima-kaihyō, but not for other regions in the Sea of Japan. High spatial and temporal resolution and good quality surface wind products will be crucial for the prediction of surface waves in the JES and other marginal seas, especially near the coastal regions. 相似文献
102.
103.
We use a synthetic data experiment to assess the accuracy of ocean tides estimated from satellite altimetry data, with emphasis on the impact of the phase-locked internal tide, which has a surface expression of several centimeters near its sites of genesis. Previous tidal estimates have regarded this signal as a random measurement error; however, it is deterministic and not scale-separated from the barotropic (surface) tide around complex bathymetric features. The synthetic data experiments show that the internal tide has a negligible impact on the barotropic tidal fields inferred under these circumstances, and the barotropic dissipation (a quadratic functional of the tidal fields) is in good agreement with the energetics of the three-dimensional regional primitive equations model which is the source of the synthetic data. 相似文献
104.
河口区治江围涂对杭州湾水动力及海床影响分析 总被引:5,自引:2,他引:5
自二十世纪六十年代起,钱塘江河口进行了大规模治江围涂,人类活动对杭州湾水域的影响越来越为人们关注。基于实测资料的分析和潮汐水流数学模型计算,探讨了钱塘江河口区围涂对杭州湾水域潮汐水流和海床的影响。研究成果可为钱塘江河口和杭州湾的进一步开发治理和环境保护提供科学依据。 相似文献
105.
赤潮生物种类特征光谱获取技术 总被引:1,自引:0,他引:1
较为系统地研究了赤潮生物水体反射率曲线获取方法。通过对 2类反射率反演方法得出的反射率曲线与实际反射率曲线进行比较 ,得出在不具备大气环境参数的情况下 ,经验线性法的反演结果与实际反射率曲线最接近的结论 ,并进一步对正常海水和赤潮生物水体的光谱特性进行分析 ,提取出赤潮生物水体的特征光谱。这是进行赤潮监测和识别的重要前提 相似文献
106.
107.
下切河谷的研究不仅可以正确划分地层、确立年代地层格架、判定沉积环境演变、探讨海平面变化规律,对碳氢化合物勘探开发、地质工程等重大国民经济建设也有重要意义。本文介绍了下切河谷体系概念、特征、划分类型、研究历程和科学意义,着重论述了晚第四纪下切河谷的形成演化、层序地层格架和控制因素。晚第四纪下切河谷体系主要是海平面下降、河流向盆地扩展并侵蚀下伏地层的下切河流体系,在海平面上升时期被充填的长条状负向地形,以区域性的地层不整合面为底界。浪控型与潮控型下切河谷体系模式有许多不同之处:① 前者存在河口砂坝、中央盆地、湾顶三角洲,后者则没有这些沉积单元;② 前者浅海沉积较薄,后者较厚;③ 前者代表了贫砂的小河河口湾,由于泥砂量少,河口湾在最大海侵线附近,后者河流作用较强,泥砂量相对大,现代河口湾不断向海扩展,较下切河谷范围要大的多;④ 前者涉及溯源堆积在下切河谷充填中的作用,但对其强度估计不足。下切河谷体系的形成演化的影响因素众多,海平面变化、沉积物供应、沉积过程、下切河谷形态和气候变化等是主要控制因素。 相似文献
108.
109.
The diurnal cycle of the tropospheric zenith total delay (ZTD) is one of the most obvious signals for the various physical
processes relating to climate change on a short time scale. However, the observation of such ZTD oscillations on a global
scale with traditional techniques (e.g. radiosondes) is restricted due to limitations in spatial and temporal resolution.
Nowadays, the International GNSS Service (IGS) provides an important data source for investigating the diurnal and semidiurnal
cycles of ZTD and related climatic signals. In this paper, 10 years of ZTD data from 1997 to 2007 with a 2-hour temporal resolution
are derived from global positioning system (GPS) observations taken at 151 globally distributed IGS reference stations. These
time series are used to investigate diurnal and semidiurnal oscillations. Significant diurnal and semidiurnal oscillations
of ZTD are found for all GPS stations used in this study. The diurnal cycles (24 hours period) have amplitudes between 0.2
and 10.9 mm with an uncertainty of about 0.5 mm and the semidiurnal cycles (12 h period) have amplitudes between 0.1 and 4.3 mm
with an uncertainty of about 0.2 mm. The larger amplitudes of the diurnal and semidiurnal ZTD cycles are observed in the low-latitude
equatorial areas. The peak times of the diurnal cycles spread over the whole day, while the peak value of the semidiurnal
cycles occurs typically about local noon. These GPS-derived diurnal and semidiurnal ZTD signals are similar with the surface
pressure tides derived from surface synoptic pressure observations, indicating that atmospheric tides are the main driver
of the diurnal and semidiurnal ZTD variations. 相似文献
110.
Hiroaki Sasaki Akihiko Tanaka Mitsunori Iwataki Yasuharu Touke Eko Siswanto Chun Knee Tan Joji Ishizaka 《Journal of Oceanography》2008,64(4):511-523
Remote sensing reflectance [R
rs(λ)] and absorption coefficients of red tides were measured in Isahaya Bay, southwestern Japan, to investigate differences in
the optical properties of red tide and non-red tide waters. We defined colored areas of the sea surface, visualized from shipboard,
as “red tides”. Peaks of the R
rs(λ) spectra of non-red tide waters were at 565 nm, while those of red tides shifted to longer wavelengths (589 nm). The spectral
shape of R
rs(λ) was close to that of the reciprocal of the total absorption coefficient [1/a(λ)], implying that the R
rs(λ) peak is determined by absorption. Absorption coefficients of phytoplankton [a
ph(λ)], non-pigment particles and colored dissolved organic matter increased with increasing chlorophyll a concentration (Chl a), and those coefficients were correlated with Chl a for both red tide and non-red tide waters. Using these relationships between absorption coefficients and Chl a, variation in the spectrum of 1/a(λ) as a function of Chl a was calculated. The peak of 1/a(λ) shifted to longer wavelengths with increasing Chl a. Furthermore, the relative contribution of a
ph(λ) to the total absorption in red tide water was significantly higher than in non-red tide water in the wavelength range 550–600
nm, including the peak. Our results show that the variation of a
ph(λ) with Chl a dominates the behavior of the R
rs(λ) peak, and utilization of R
rs(λ) peaks at 589 and 565 nm may be useful to discriminate between red tide and non-red tide waters by remote sensing. 相似文献