Numerical simulation of the offshore typhoon waves based on SWAN model and mild-slope equation

本文综合考虑了台湾海峡水深地形、海峡宽度、两岸地形引起的风速变化、台风中心位置等因素对台风风场结构的影响，提出了台湾海峡台风风场的改进模式，再联合SWAN波浪模型和改进的椭圆型缓坡方程，利用波谱离散驱动边界，建立了台湾海峡和近岸波浪场数值嵌套模型。并选取0908号“莫拉克”台风过程的实测数据进行模型风场和波浪场的率定分析，结果表明，“莫拉克”台风过程期间模拟风速的平均绝对误差小于5m/s，相对误差普遍低于20%；有效波高的均方根误差小于0.5m，计算结果较好地反映海峡内波浪对台风的响应过程。并应用该模型对0903号“莲花”台风期间台湾海峡波浪场的演变过程进行示范性后报模拟，以检验该模型投入预报...The present thesis proposes a modified typhoon wind field model around the Taiwan Strait by taking all factors that affect the typhoon wind field into consideration, such as the depth and topography of Taiwan Strait, the strait width, bilateral terrain of the strait, the position of typhoon center. Combining the SWAN (Simulating Waves Nearshore) model and the modified elliptic type mild-slope equa...学位：理学硕士院系专业：海洋与环境学院海洋学系_物理海洋学学号：2242010115135

航天传感器响应波段星等计算方法

精确的恒星星等信息是开展导航星表建立、航天器定姿、红外相机定标等工作的基础，现有公开星表涵盖测光波段不全且带宽普遍较窄，难以找到与任务传感器响应波段相匹配的星等信息。为此提出了一种基于恒星辐射光谱的传感器响应波段星等计算方法。该方法利用公开星表数据信息，建立星表测光波段与传感器响应波段星等差值模型，对星表星等与传感器响应波段星等差值进行估算；将色指数计算的恒星近似表面温度作为先验信息，在传感器响应波段区间进行普朗克方程求解，进而推算恒星在传感器响应波段的星等。星表数据计算验证表明，该方法具有较好的稳健性和适应性，对传感器响应波段星等推导精度为0.066等 （1δ），93.3%恒星推算误差优于0.2等，可满足导航星表建立、航天器定姿、红外相机定标等应用需求

Distribution Characteristics of Suspended Sediment and Dynamic Analysis in the Xiamen Bay

利用2011年1月厦门湾3个观测站声学多普勒流速剖面仪(AdCP)回波强度数据与现场水样采集反演出了悬沙浓度,并估算了单宽输沙量.经统计分析表明,厦门湾冬季1月份整体悬沙浓度较小,西海域悬沙浓度大于东海域,近水面悬沙浓度小,由表层到底层逐渐递增;而在时序分布上,悬沙浓度变化与潮流密切相关,呈现出往复运移的趋势,并且大潮期间的悬沙浓度大于小潮期间的悬沙浓度.此外,厦门湾内单宽输沙量一般在半潮面时最大,而在湾外,单宽输沙量在接近平潮或停潮时达到最大,冬季净输沙量整体较小.The suspended sediment concentration(SSC) and the sediment transport rate in Xiamen Bay were calculated,based on the backscattered signals observed by the acoustic doppler current profilers(ADCP),which had been calibrated against in situ bottle samples of the suspended sediment in January 2011.The statistical analyses show that the SSC of Xiamen Bay is low in January,and the SSC in Xiamen Western Bay is larger than the SSC in Xiamen Eastern Bay.The retrieval results also show regular vertical variation,that the SSC increases from the surface layer to bottom layer.Moreover,by analysis of time series,the SSC variations in a tidal cycle also have close relation with tidal currents.In addition,the high concentrations of suspended sediment coincide with the stronger tidal currents due to the tidal dispersion and vertical mixing.Furthermore,the net sediment transport is low in winter and sediment transport rate reaches its maximum in a tidal cycle at half-tide level in the inner bay of Xiamen,while the maximum of sediment transport rate is at slack tide in the outer bay.福建省科技厅专项经费项目(2010Y0064); 厦门市海洋与渔业局专项经费项

Numerical simulation of typhoon waves in the waters around Xisha Bay,Fujian during 0908 typhoon Morakot

联合SWAn模型和改进的椭圆型缓坡方程,结合考虑台湾海峡地形效应的改进藤田公式风场模型,建立了台湾海峡及近岸波浪场的数值嵌套模式.边界采用波谱离散驱动,模拟了0908号台风“莫拉克“期间台湾海峡波浪场的演变和崇武西沙湾浅水台风浪传播的物理过程.以实测数据进行单点验证表明,整个模拟过程风速的平均绝对误差为3.38 M/S,波高的平均绝对误差为0.30 M,计算结果较好地反映海峡内波浪对台风的响应过程.“莫拉克“台风登陆台湾岛时,台湾海峡有效波高最大值为5.0 M;台风中心进入台湾海峡后,海峡东北部为巨浪到狂涛,有效波高最大值可达10.5 M.接近福建崇武沿岸时,偏E向台风浪向西沙湾内近岸传播,发生浅化、破碎、反射、绕射等变形现象,有效波高最大不足2 M,最小仅为0.2 M,波向趋于SE向,波峰线则趋于与峡湾岸线平行;崇武闽台贸易码头附近,大部分波浪受到阻挡作用发生反射,少部分发生绕射,使得码头以北水域波浪较小,有效波高仅为0.2~0.6 M,对湾内避风坞起到较好的保护作用.Combining the SWAN model and the modified elliptic type mild-slope equation,the paper proposed the nested wave model of the Taiwan Strait and coastal waters,also included the wind field model based on a modified Fujita formula that considers the terrain effect of the Taiwan Strait.Using the driving of wave spectrum discretization,it could simulate the evolution of the wave field in the Taiwan Strait and the physical propagation processing of typhoon waves in the Chongwu Xisha Bay during the typhoon Morakot(0908).Comparision with measured data showed that the mean absolute deviation of the wind in the whole simulation process was 3.38m/s,and that of the wave was 0.30m,so the simulating results reflected the response of wave in the strait to typhoon well.Morakot landed on Taiwan with the maximum significant wave height of 5.0m in the strait.After the typhoon center moved into the strait,the waves of northeast strait became high or very high,and the maximum significant wave height was 10.5m.Moreover,it occurred that shoaling,wave breaking,reflection,and diffraction when the typhoon center approached Chongwu and the east typhoon wave propagated into Xisha Bay,then the maximum significant wave height was less than 2m and the minimum value was 0.2m.While the wave direction turned into southeast,and the wave crest line approached to be parallel to the fjord coastline gradually.Owing to the blockade by the trade dock,most waves were reflected and a few waves were diffracted into the bay,making the wave around the north dock very small,with a significant wave height of only 0.2 to 0.6m,and it could protect the shelter port in inner bay to a relatively good extent.福建908专项资助项目(FJ908-01-01-ZH); 国家海洋局海洋公益性行业科研专项资助项目(201005012-4); 福建省科技计划重点资助项目(2010Y0064