科尔沁沙地奈曼旗近5年来风况及合成输沙势

应用奈曼沙漠化研究站1998-2002年的气象资料, 统计分析了奈曼旗近5a来的风况特征和输沙势。结果表明: ①研究区3~5月起沙风发生频数最高, 占全年起沙风的38%~58%; 平均风速和最大风速值最大, 分别为6.0~7.5m·s^-1和9.5~16.9m·s^-1。该风况特征与地表冻融、裸露、干旱疏松相耦合, 形成了区内的风沙活动期。②在风沙活动期内, 风环境基本为锐双峰风况, 西北风居主导地位, 频数占54%; 南风和西南风次之, 频数占38%。③在风沙活动期内, 研究区属于高风能环境, 合成输沙势RDP为66.3VU(风速以m·s^-1为单位), 合成输沙方向RDD为ESE113°。     

Local Similarity Relationships of Non-Dimensional Wind and Temperature Gradient in the Tower-Layer Atmosphere over Beijing City

Micrometeorological data for wind and temperature from a 325 m high tower in Beijing City are analyzed by use of local similarity theory. Non-dimensional wind and temperature gradients, Фm and Фh, are determined by three techniques called, respectively, eddy-correlation, mean profiles and inertia-subrange cospectra (ISC) method for a wide range of atmospheric stratification from unstable to stable conditions. Average dissipation rate Фε of turbulent kinetic energy (TKE) is evaluated from u-spectrum, as a quantity required in the last technique. Ratio of the eddy transfer coefficients. α (= Kh / Km,), is calculated from Фm and Фh estimations. The results from various techniques are compared with each other and with some available empirical results in the tower-layer. It is shown that the empirical relationships determined by mean profiles and ISC methods in the tower-layer turbulence are in agreement with each other and with some other results.     

Evidence for solar forcing of climate variation from δ18O of peat cellulose

There have been a number of investigations for examining the possible link between long-term climate variability and solar activity. A continuous δ¹⁸O record of peat cellulose covering the past 6 000 years and the response of climate variation inferred from the proxy record to solar forcing are reported. Results show that during the past 5 000 years the abrupt climate variations, including 17 warming and 17 cooling, and a serious of periodicities, such as 86, 101, 110, 127, 132, 140, 155, 207, 245, 311, 820 and 1 050 years, are strikingly correlative to the changes of solar irradiation and periodicity. These observations are considered as further evidence for a close relationship between solar activity and climate variations on time scales of decades to centuries.     

测震学中期异常向短临异常演变特征的探讨

以晋、冀、蒙三省交界地区的4次6级左右地震为例,研究了中期异常向短临异常演变的特征.此特征可由地震活动图象异常、地震平静与密集、信号震到加卸载响应比异常、日频次起伏加剧的演变来表征,在时间进程上它们是一个渐进的过程.     

临猗ML5.0级地震前后的重力场变化及预报过程

讨论了气压、地形变、降雨和地下水位变化对重力观测资料的影响,论证了观测资料的可靠程度,在此基础之上结合地质构造,地壳深浅构造等资料,讨论了１９９８年７月１１日临猗地震前后重力场的变化;依据临猗地震前重力场的变化,结合该地区的地震活动性,对这次地震作出了预报。     

渤海悬浮颗粒物的三维输运模式 I.模式

为了长时间,大范围研究渤海中悬浮物的输运规律,研究应用并改造了备国汉堡大学的粒子追踪悬浮物输运的三维模式,模式中考虑了风、气压等气象要素以外海传入的潮波作用下的三维正压海流对悬浮颗粒物的输运．同时考虑了悬浮颗粒物的学降及再悬浮机制和底质中的细颗粒物的运动,将风浪的作用引入了悬浮物输运的计算,数值模式应用的粒五追踪方法,能较好地反映悬浮物浓度的迅速变化。     

关于风浪预报公式和风区宽度的注记

从定常波的风浪波高随风距成长的预报公式出发 ,在一定条件下 ,导出各波向上风浪波高分量与该波向上的风距之间的关系 ,以便在不规则风区上推算风浪波高和平均波向 ;同时 ,对风区宽度作了定量化的分析。     

风浪槽内风浪外频谱谱形的一些特征

利用实验室风浪槽内测得的波面序列资料估计风浪外频谱。通过与实测风浪内频谱的比较,研究实测风浪外频谱的谱形特征,探讨海浪外频谱与内频谱的相似性问题。此外,还检验一种理论海浪外频谱。     

Solar wind variation with the cycle

The cyclic evolution of the heliospheric plasma parameters is related to the time-dependent boundary conditions in the solar corona. “Minimal” coronal configurations correspond to the regular appearance of the tenuous, but hot and fast plasma streams from the large polar coronal holes. The denser, but cooler and slower solar wind is adjacent to coronal streamers. Irregular dynamic manifestations are present in the corona and the solar wind everywhere and always. They follow the solar activity cycle rather well. Because of this, the direct and indirect solar wind measurements demonstrate clear variations in space and time according to the minimal, intermediate and maximal conditions of the cycles. The average solar wind density, velocity and temperature measured at the Earth’s orbit show specific decadal variations and trends, which are of the order of the first tens per cent during the last three solar cycles. Statistical, spectral and correlation characteristics of the solar wind are reviewed with the emphasis on the cycles.     

谱线分析法测定ζAur型系统的 红巨星星风物质损失

用双星技术（Binary-technique）的谱线分析方法来测定双星系统中的红巨星或红超巨星的星风物质损失率是目前最为精确的。扼要介绍了此类方法的一般原理以及在ζAur/VVCep双星系统的物质损失测量中的应用。同时介绍了该方法的最新进展,并展开与此有关的一些简要讨论。