The perturbation characterization of reverberation from awind-generated bubbly ocean surface. I. Theory and a comparison ofbackscattering strength predictions with data     

Kuo  E.Y.T. 《Oceanic Engineering, IEEE Journal of》1994,19(3):368-381

A joint surface roughness/volumetric perturbation scattering theory is utilized to characterize bubbly ocean surface reverberation. Backscattering strength predictions are shown to be consistent with observed reverberation phenomena such as critical wind speeds, excess levels due to volumetric scattering, and saturation  相似文献   

Sea surface scattering and propagation loss: review, update, andnew predictions     

Kuo  E.Y.T. 《Oceanic Engineering, IEEE Journal of》1988,13(4):229-234

Sea-surface-scattering loss estimates based on perturbation methods are reviewed. The perturbation method has been known to be quite accurate for estimating low-frequency acoustic wave scattering loss. The author compares models that are based on the perturbation methods of H.W. Marsch (1961) and F.G. Bass (1960). Predictions based on numerical integration in a complex domain are presented and compared to previous predictions  相似文献   

Acoustic wave scattering from two solid boundaries at the oceanbottom: reflection loss     

Kuo  E.Y.T. 《Oceanic Engineering, IEEE Journal of》1992,17(1):159-170

An acoustic wave scattering model is formulated and solved for three homogeneous layers consisting of a thin solid sediment layer sandwiched by semi-infinite water and solid basalt media. The model is applied to two cases to analyze both the physical parameters affecting reflection loss and the effects of interface roughness scattering. It is shown that effects of attenuation in the sediment layer, especially of S-waves, combine with conversion and scattering processes of the basalt interface to constitute the dominant mechanism of reflection loss, especially in the small grazing angle directions. The scattering process is found not only to produce the well-known acoustic energy loss from specular to nonspecular directions, but also to alter the conversion efficiency between P and S waves with a resulting loss or gain  相似文献   

A search for split SKS waveforms in the North Atlantic     

Ban-Yuan Kuo  Donald W. Forsyth 《Geophysical Journal International》1992,108(2):557-574

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大气低频振荡对2015年冬季华北强降温事件的影响          下载免费PDF全文

李丽平  付佳丽  梁阔  李一格  高辉 《大气科学学报》2022,45(5):778-790

利用1980—2016年中国日最低温度和NCEP/NCAR再分析资料,分析了大气低频振荡对华北2015年冬季区域强降温事件（Regional Extremely Cold Event,简称RECE）的影响。结果表明：1）两次过程均与最低温度10～20 d低频分量从峰到谷值的变化相应。2）第一（二）次过程巴尔喀什湖-贝加尔湖（简称巴-贝湖）高压位置偏西（偏东北）,西伯利亚高压偏南（偏北）,东亚大槽呈东北-西南（南-北）走向,阿留申低压偏深（偏西偏深）,无（有）北极涛动负异常,高低层冷空气源地均位于贝湖北部60°N附近（巴湖以北上空和华北局地）,降温较慢（快速）。地中海低频扰动能量的持续输送是造成两次降温过程持续时间差异的原因之一。3）-18 d （-12 d）500 hPa高度场中西欧低频负（正）异常,是华北强降温事件的延伸期预报参考信号。  相似文献   

2021年河南“7.20”极端暴雨动、热力和水汽特征观测分析     

冉令坤  李舒文  周玉淑  杨帅  马淑萍  周括  申冬冬  焦宝峰  李娜 《大气科学》2021,45(6):1366-1383

利用MICAPS观测降水数据、欧洲气象中心ERA5再分析资料和FY-4A卫星云顶亮温数据,对2021年7月20日河南极端暴雨进行综合分析。结果表明,此次暴雨受200 hPa两槽一脊、大陆高压、副热带高压（副高）西伸北抬和台风“烟花”西移、“查帕卡”台风倒槽等多尺度天气系统共同影响,黄淮气旋的西南气流与副高和“烟花”之间的东南气流稳定控制河南地区,边界层急流供应充沛水汽,在太行山和嵩山迎风坡辐合抬升,致使河南暴雨长时间维持,产生极端降水量。西南气流穿过从广东和广西延伸到河南的高湿带,副高和“烟花”引导东南气流经过从东海洋面延伸到河南的相对较弱湿区,这两条水汽输送带在太行山和嵩山地形阻挡下汇合在河南北部,为暴雨供应水汽。丰富的可降水量、水汽过饱和、深厚暖云层以及降水系统较强的水汽消耗率为郑州高降水效率提供有利条件。郑州低层大气经历多次从强层结不稳定到弱层结不稳定的转化,边界层急流引起的垂直风切变和气流辐合对层结稳定度变化有重要影响。黄淮气旋内部中尺度涡旋对河南暴雨发生发展至关重要,不但提供西南气流,还产生较强的位势高度纬向平流,增强边界层急流。嵩山与太行山余脉构成喇叭口地形,边界层急流在嵩山北侧和东侧爬坡,促使山前水汽堆积,激发和加强暴雨。中尺度云团合并小尺度云团,发展成结构密实的孤立云团,稳定少动,对暴雨有重要影响。降水区上空广义湿位涡异常,由于广义湿位涡能够刻画中尺度系统的垂直风切变、涡度以及大气湿斜压性和层结不稳定等动力和热力因素垂直结构特点,所以对中尺度系统和降水落区有一定指示意义。  相似文献   

Reply     

C. Kuo  Y. Welaya 《Ocean Engineering》1982,9(1):101-102

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A review of intact ship stability research and criteria     

C. Kuo  Y. Welaya 《Ocean Engineering》1981,8(1):65-85

An investigation on capsizing of a vessel in a seaway is of paramount importance from the point of view of safety of life at sea. The present paper analyzes the major research efforts made throughout the world regarding intact stability and the establishment of stability criteria. Attempts have been made by the authors to draw conclusions from this analysis and to provide guidelines for future research efforts in the field of intact stability of ships.  相似文献   

A Study of Bispectra in Relation to the Adequacy of Wave Spectral Model     

Yi-Yu Kuo  Chung-Ching Chien John Y. Yim Professor 《中国海洋工程》1997,(2)

In this paper.the characteristics of laboratory wind waves under various wind speeds and wat-er depths are studied.It is found that either the real or the imaginary part of the bispectrum can be relatedto the asymmetry of the wave profile,and the bicoherence is related to the ratio of nonlinear to linear wavecomponent.Occasionally,these two categories of nonlinear index lead to opposite inferences,because eachof them has its own significance and functions.The applicability of linear wave spectral model in oceanwaves becomes questionable only when strong nonlinearity is indicated by both of these two indexes.Thelinear spectral representation of wave fields does not necessarily become inadequate as water depth de-creases,and its appropriateness can be examined through the characteristics of the bispectrum.  相似文献   

西沙群岛和中沙群岛及其附近海域囊甲藻属的分类研究     

郭玉洁  周汉秋  叶加松 《海洋科学集刊》1979,(15):47-56

囊甲藻属是广泛分布在热带和亚热带海洋的一类发光甲藻。早在1872-1876年“挑战者号”航海调查(“Challenger”Expedition)中，Murray即建立了囊甲藻属，并注意到这些囊甲藻个体能产生明显的燐光，其后的调查也多次证明本属中的大部分种类都明显发光。截至目前，在世界上已记录囊甲藻12种、2变种和1变型(包括生活史还未完全了解的种类)的形态和分布。近十年来，对本属种类的亚显微构造、生活史和分类地位等也陆续作过一些研究，但仍有不少问题需要澄清。 本文是根据1974年5-6月和1975年3-4月在我国西沙群岛、中沙群岛及其附近海域，以网目边长为64微米的浮游植物网所采得的资料进行研究的，共报告囊甲藻属5种、1变种和1变型。截至目前，国内对本属尚无报道，本文中论及的种类都是我国的首次记录。  相似文献