干旱指标研究进展及中美两国国家级干旱监测

分析比较了国内外常用的一些干旱指数如降水量距平、标准化降水指数及PDSI等的原理和计算方法。对美国和中国国家级干旱监测业务的发展与现状进行了综述,并详细地介绍了两国干旱监测业务流程、监测方法、产品内容及各自的干旱等级规定、影响评估及预警情况等。     

The ozone trend in the layer of 2 to 3 km a.s.l. since 1978 and the typical time variations of the ozone profile between ground and 3 km a.s.l.

Summary Longterm recordings of the O₃ concentration at the Zugspitze in 2964 m a.s.l. and at the Wank peak in 1780 m a.s.l. together with continuous daily measurements of cosmogenic radio-nuclides have been analyzed in order to ascertain whether or not a significant trend of O₃ exists. Recordings from 1981 to 1988 show definitely that there was no trend of the O₃ concentration in the free atmosphere between 1.8 and 3 km a.s.l. However, an increase of 10 ppb occurred 1978 to 1981.A cable car operating between Zugspitze and the valley (in 1000 m a.s.l.) over a two km height difference at the northern border of the Bavarian Alps has been used for atmospheric research. The run of this cable car is rather steep and is mostly suspended far away from the ground. Consequently it is ideal for simulataneously investigating the profiles of meteorlogical and atmospheric electrical parameters, and the ozone concentration. From 1980 to 1982 a total of 1990 ozone profiles have been recorded on fair weather days. The data collected offer a profound basis in order to study the time variations in the lower tropospheric ozone profile depending on the hour of the day during all seasons. The influence of the following atmospheric processes and conditions on the O₃ profile pattern has been investigated:Vertical mixing intensity in and above the boundary layer, temperature inversions, photochemical production of ozone or its depletion in the lowermost layers, and stratospheric intrusions based on the measurements of cosmogenic radionuclides on Zugspitze, the upper end of the trail. The penetration depth of stratospheric O₃ in the lower troposphere has been investigated and the shape and time behavior of temporarily O₃ maxima within the boundary layer has been studied.With 12 FiguresExtended version of a paper presented at the International Conference on the Generation of Oxidants on Regional and Global Scales, held at the Univ. of East Anglia, Norwich, England, 3–7 July 1989.     

2006年“04、05”号热带气旋的诊断分析

通过诊断“04、05”号热带风暴登陆后减弱成台风低压的变化特征，分析其路径相似却出现降水实况不同的成因，结果表明：台风低压暴雨主要决定于登陆后台风低压的移动路径和高低层结构维持时间的长短，稳定的湿舌、“湿锋”、台风低压辐合线的持续加强、急流的北推西进以及有利地形都可使降水得到明显增幅。     

2006年"04、05"号热带气旋的诊断分析

通过诊断“04、05”号热带风暴登陆后减弱成台风低压的变化特征,分析其路径相似却出现降水实况不同的成因,结果表明:台风低压暴雨主要决定于登陆后台风低压的移动路径和高低层结构维持时间的长短,稳定的湿舌、“湿锋”、台风低压辐合线的持续加强、急流的北推西进以及有利地形都可使降水得到明显增幅。     

Tree-ring reconstructed rainfall over the southeastern U.S.A. during the medieval warm period and little ice age

A 1053-year reconstruction of spring rainfall (March-June) was developed for the southeastern United States, based on three tree-ring reconstructions of statewide rainfall from North Carolina, South Carolina, and Georgia. This regional reconstruction is highly correlated with the instrumental record of spring rainfall (r = +0.80; 1887–1982), and accurately reproduces the decade-scale departures in spring rainfall amount and variance witnessed over the Southeast during the past century. No large-magnitude centuries-long trends in spring rainfall amounts were reconstructed over the past 1053 years, but large changes in the interannual variability of spring rainfall were reconstructed during portions of the Medieval Warm Period (MWP), Little Ice Age (LIA), and the 20th century. Dry conditions persisted at the end of the 12th century, but appear to have been exceeded by a reconstructed drought in the mid-18th century. High interannual variability, including five extremely wet years were reconstructed for a 20-yr period during the late 16th and early 17th centuries, and may reflect amplified atmospheric circulation over eastern North America during what appears to have been one of the most widespread cold episodes of the Little Ice Age.     

Connections between the U.S. national temperature,the 10.7 cm solar flux and the equatorial QBO

Summary A comparison of the solar flux in January and February with the United States national temperature does not show any evident connection during the period 1952–1987. However, when the data are separated according to the east or west phase of the quasi-biennal oscillation (QBO) in the equatorial stratosphere the following phenomenon is found. When the QBO was in its west phase the U.S. national temperature is negatively correlated with the solar flux cycle; the opposite holds true for the east phase of the QBO.With 2 Figures     

农经网服务"三农"的经济学效益浅析

利用价格弹性理论、成本分析理论等微观经济学的基本概念和理论,以贵州省及贵阳市农经网为例,分析研究农经网服务“三农”的经济学效益,以期为农经网的建设和发展提供一些理论依据。     

Updated Precipitation Series for the U.K. and Discussion of Recent Extremes

We present an automated method for updating existing long-running precipitation series in near-real time. Our analyses confirm the trend towards significantly drier summers in the south-east of England and significantly wetter winters in the west of Scotland. In 2000 England and Wales saw the wettest April since records began in 1766 and record-breaking daily precipitation in several regions in October led to the wettest autumn on record.     

Comments on ‘the characteristics of turbulent velocity components in the surface layer under convective conditions’, by H. A. Panofsky,H. Tennekes,D. H. Lenschow,and J. C. Wyngaard

Panofsky et al. (1977) have presented an analysis which seems to show a clear dependence of the dimensionless turbulence statistics _u /u _* and _v/u _* on the planetary boundary-layer stability parameter z _i/L. However it is possible that much of the apparent relationship results from artificial correlations introduced by the use of inter-related dimensionless parameters. Apparent dependencies of similar statistical quantities on z/L in the surface boundary layer might also be contaminated.This work was supported by the U.S. Department of Energy, and is a contribution of the Multistate Atmospheric Power Production Pollution Study (MAP3S).     

Policy solutions in the U.S.

The paper focuses on relocation, retreat, zoning, insurance, and subsidy as major dimensions of coastal hazard mitigation measures that have resurfaced as potent forces for combating coastal inundation and climate change. It reviews the issues surrounding the practice of these measures and discusses compatibilities of policies, engineering measures, and natural defense. Property rights, development interest, and distorted financial incentives pose as main barriers to coastal relocation and retreat policies in hazard-prone areas. To understand and propose coastal adaptation solutions, the paper recommends place-based studies of local coastal adaptation strategies. Place-based studies offer an in-depth knowledge of local conditions specifically regarding the level of implementation of hazard mitigation policies, and shed light on important trade-offs and synergies of various hazard policies. In addition, coupling existing hazard mitigation policies with coastal management and community management can better inform long-term and comprehensive planning of coastal adaptation.