龙门山地区泥盆纪锶、碳同位素与海平面变化

文章将龙门山地区泥盆系划分为四个沉积旋回,即四个地层层序,建立了该区泥盆纪海相碳酸盐锶、碳同位素地层曲线,并将同位素演化与沉积旋回结合起来研究该区泥盆纪的海平面变化。     

莱州湾东南沿岸海水入侵发展规律与趋势预测

对莱州湾东南沿岸地区海水入侵的特点和规律进行了分析，并以灰色系统模型ＧＭ对该地区海水入侵的发展趋势进行了预测，最后提出了防治海水入侵的对策建议。     

A weak El Nio event in 2002 detected by the astronomical observation

Using the length-of-day (LOD) data series derived from astronomical observations made by various modern space techniques, southern oscillation index (SOI) and anomalies of sea surface temperature (SST) in tropical Pacific Ocean, the inter-annual components of these data series are obtained by the technique of band filtering from January 1962 to October 2002. It is found that a new ENSO event has already occurred in 2002 and been detected by the interannual LOD. It is shown by the wavelet analysis that the component with a period of about 4-6 years and the quasi-biennial component are out of phase during 2001-2002, which consequently suggests that the new ENSO event cannot be a strong one.     

Coupling and propagating of mesoscale sea level variability between the western Pacific and the South China Sea

The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves.     

福建东山湾海浪现场观测的统计特征

为分析福建省南部港湾──东山湾的波浪特征,采用S4型压力式方向波浪仪观测获取现场一个月的风浪过程资料,对其进行了统计分析和频谱分析,给出了波高和周期分布,特征波要素与频谱关系,结果表明:实测波高分布与瑞利分布基本相符;波浪谱的显著部分在狭窄的频率内,对应3、5、6、7级风谱峰密度值(m2s)分别为0.084 3、0.372 8、0.941 8、1.837 7,随着风速的增加,谱能也显著地增加,谱曲线下面的总面积增大,谱的显著部分波及的频率范围也扩大,且谱的显著部分沿低频率的方向推移,对应风浪的波高及周期范围增大.     

Relationship between the tropical cyclone genesis over the Northwest Pacific and the sea surface temperature anomalies

Using the tropical cyclone (TC) data derived from the Joint Typhoon Warning Center (JTWC) and the sea surface temperature data derived from the Joint Environmental Data Analysis Center (JEDAC) at the Scripps Institute of Oceanography from January 1955 to December 2000, we analyzed the relationship between the TC genesis over the Northwest Pacific (NWP) and the sea surface temperature anomalies (SSTA) over the Pacific basin. A long-term trend indicated that the highest frequency of monthly TC genesis appeared earlier and the annual genesis sum increased gradually during the last half century with some oscillations. No significant synchronous correlation was found between the NWP TC events and the SSTA over the Pacific basin, while the annual sum of TC genesis was closely related with the SSTA averaged from the first three months (January, February and March) of the year in the equatorial western and eastern Pacific and over mid-high latitudes of the North Pacific. The results implied that there are an interannual El Nio SSTA mode in the equatorial western and eastern Pacific and an interdecadal SSTA mode in the northern Pacific, which affected the TC genesis. A regression analysis between the first three-month SSTA and the annual TC sum based on two time scales was conducted. The correlation coefficient between simulated and observed TC sums reached a high value of 0.77.     

Relationship between the tropical cyclone genesis over the Northwest Pacific and the sea surface temperature anomalies

Using the tropical cyclone (TC) data derived from the Joint Typhoon Warning Center (JTWC) and the sea surface temperature data derived from the Joint Environmental Data Analysis Center (JEDAC) at the Scripps Institute of Oceanography from January 1955 to December 2000, we analyzed the relationship between the TC genesis over the Northwest Pacific (NWP) and the sea surface temperature anomalies (SSTA) over the Pacific basin. A long-term trend indicated that the highest frequency of monthly TC genesis appeared earlier and the annual genesis sum increased gradually during the last half century with some oscillations. No significant synchronous correlation was found between the NWP TC events and the SSTA over the Pacific basin, while the annual sum of TC genesis was closely related with the SSTA averaged from the first three months (January, February and March) of the year in the equatorial western and eastern Pacific and over mid-high latitudes of the North Pacific. The results implied that there are an interannual El Nio SSTA mode in the equatorial western and eastern Pacific and an interdecadal SSTA mode in the northern Pacific, which affected the TC genesis. A regression analysis between the first three-month SSTA and the annual TC sum based on two time scales was conducted. The correlation coefficient between simulated and observed TC sums reached a high value of 0.77.     

试析环境演变对史前人类文明发展的影响--以长江三角洲南部平原良渚古文化衰变为例

良渚先民受自然环境的制约和经济生活模式的决定,连片成串地集中分布于长江三角洲南部平原,良渚早中期的温干气候和适宜环境使良渚文化空前繁荣,但在距今4000年左右突然消亡.作者通过研究,发现在距今4100年左右存在明显的降温事件,降温使农作物歉收,食物匮乏,在部落间引起连绵战争,使良渚文化走向衰弱.而距今3600年左右的海平面升高,在长江三角洲南部平原发生沟谷海侵,地下水位升高,太湖湖泊体系迅速扩张,引起大洪水,导致良渚文化消亡.     

扩频雷达探测一阶海洋回波

利用扩频通信良好的抗干扰性和低功率谱密度下工作的特点，本文把扩频技术引入高频海洋探测雷达来探测海洋一阶回波，研究结果表明，该技术对回波质量无不良影响，同时可降低雷达发射功率，增加雷达探测距离．