浅谈业务网络安全

1引言随网络技术的发展,人们对业务网络的安全也越加重视。尤其最近暴发的“红色代码”、“蓝色代码”及“尼姆达”等病毒,加深了认识网络安全的重要性。网络的生命在于其安全性。因此,如何在现有的条件下,搞好网络的安全,成了网络管理人员的一项重要任务。下面结合对WINDOWS NT网络管理的一点经验与体会,在技术方面提出对业务网安全的一些看法。     

自动站大风报警程序设计

1引言在自动站投入使用前绝大多数气象站使用的是EL型风向风速计,其瞬间风速是通过风速指示计人工测得的,人为因素大,精度不够,但人工测量给大风重要天气报、大风危险和解除报提供了依据,不会出现大风记录和报文之间的矛盾现象,而自动站的大风记录却不一样,其记录的大风的起止时间,极大风速及出现的时间是非常精确的,要求值班员实时注意查看自动站的大风记录,避免漏报、错报。由于自动站采集控制软件SAWSS在处理大风记录时存在不足,当大风达到不同的发报标准时不能及时报警,以提醒值班人员作出相应的处理,所以极易造成过时报,甚至漏报。     

巧修虹吸雨量计浮子

地面气象常规仪器的零配件近年来十分紧缺,特别是虹吸雨量计的浮子。浮子是虹吸雨量计中最重要的零件,而浮子又最容易冻坏。例如,牡丹江地区2005年5月6～9日4d内,先是下了雨,后又转雨加雪、雪,绥芬河站的降水量近30mm。温度最低降到1.6℃,虹吸雨量计的安装时间和拆卸时间很难掌握,安装太迟或拆卸太早都可能影响到年度15个时段最大降水量的挑选。由于气候变化和人为因素造成浮子冻坏的现象屡见不鲜,一旦浮子底部冻裂而又没有备份浮子,为了气象资料的完整性可采取巧焊浮子的方法,焊好待用,有了新的浮子再更新。     

自动气象站出现故障编发报文的几种方法

1引言伊春自动气象站是国家基本站(现改为一级站),每天担负8次天气报,资料参加全球交换。当计算机出现故障时,天气报是否能在规定的时间内准确的编发出是至关重要的。出现故障时,在短时间内准确的手工编发出报文难度很大,容易出现错情或造成迟报等重大错情。为了避免这种情况的发生,总结了以下几种方法进行编发报,降低了出错的几率。     

不同显式方案模拟对流风暴的不确定性

利用MM5模式选取mixed phase、graupel(gsfc)、graupel(reisner2)和schultz 4种显式方案对理想的对流风暴进行水平分辨率为2 km的全显式数值模拟,分析不同显式方案模拟的对流风暴不确定性.结果表明:不同的显式方案模拟的对流风暴的最大垂直速度、水平结构和降水以及云物理量的演变都有很大的不确定性,说明要对实际降水进行全显式的数值预报可能需要对不同显式方案导致的预报结果的不确定性作出进一步的估计,集合预报中可能要考虑不同显式方案对预报结果不确定性的影响.     

MODIS近红外大气可降水含量与乌鲁木齐地基GPS水汽数据的对比分析

本研究在建立HDF数据图像显示、数据提取和分析平台的基础上,利用乌鲁木齐地基的GPS水汽数据,对比分析了2004年6月2日-8月2日之间37d的MODIS近红外大气可降水含量的精度.发现MODIS反演的近红外PW系统性地比GPS探测的PW偏小,但在变化趋势上是相似的,说明MODIS反演的近红外大气可降水含量还是能够反映水汽的变化趋势.37d中降水出现的日期对应于PW的大值日期,尤其与GPS的大PW日数非常吻合.MODIS近红外大气柱可降水含量能够提供大面积水汽空间分布数据.每天一次的水汽分布数据能够用于研究水汽的时空分布和气候特征.该研究开发的MODIS水汽数据分析处理平台也可应用于其它MODIS反演产品的分析,如地表面温度、气溶胶光学厚度等.     

研究气象学所必需的工具

本篇原名Meteorology for Schools and Colleges,是Sir Napier Shaw应TheRoyal Meteorological Society会长的嘱托而作的。他以为观测,列表,制图,图解,预报等基本工作是一个中学生的能力所能及的,对观测结果的物理原因的探求,则非大学程度不行,所以在这中间划了一道高等气象学(Meteorology forColleges)和初等气象学(Meteorology for Schools)的界线。本篇的内容,注重在指示一个中学生或初等气象学者,须怎样地去修养,才能使他自己成为一个研究高等气象学的学者。依照我们的环境,也许这篇是值得我们读一下的吧。     

秋天

风就那么轻轻地扇了一下,整个荒原就着了火,不停奔忙的救火人却面带微笑。站在垄上,我的心在随着他们的韵律激动地博跳。金黄色玉米,黄金样水稻,所有的稼禾都积极地     

电子设备接地线的长度与使用材料规格的探讨

1引言电子设备的接地系统一般包括直流工作地、交流工作地、安全保护地,3种接地线在某一公共点接在一起后再通过等电位连接到接地体上。一个良好的接地系统除了必须有良好的接地体以外,接地线的长度和用材规格是极其重要的方面。实际工作中不同设备对接地线的长度和用材规格要求不一样,不同的参考资料给出的接地线长度、用材规格也往往不同,使工程技术人员容易混淆。因此,从理论上估算与校验显得非常重要。     

西安大雾气候特征及成因分析

为揭示西安地区大雾气候特征及成因,分析西安地区1961-2005年大雾日数和对应的相对湿度、气温.结果表明:西安大雾最多地区是西安城区,秋冬季是大雾的高发季节;西安城区和户县大雾有明显的减少趋势,长安、蓝田大雾有明显的增加趋势,西安冬季大雾变化最明显;西安大雾具有明显的年代际变化;西安大雾变化与相对湿度和气温的变化有一定的相关性.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any     

Index to Vol.31

正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;     

Information for Contributors

正Journal of Meteorological Research is an international academic journal in atmospheric sciences edited and published by Acta Meteorologica Sinica Press,sponsored by the Chinese Meteorological Society.It has been acting as a bridge of academic exchange between Chinese and foreign meteorologists and aiming at introduction of the current advancements in atmospheric sciences in China.The journal columns include Articles.Note and Correspondence,and research letters.Contributions from all over the world are welcome.     

前寒武纪气候演化中的三个重要科学问题

自地球形成至寒武纪将近40亿年（距今46亿～5.4亿年,通常称为前寒武纪）的气候演变是一个具有特殊难度和挑战性的研究领域,同时也是基础和前沿的研究领域。文章选择了前寒武纪气候演化中的三个重要科学问题进行综述：大气演化、两次全球性的冰川期以及暗弱太阳问题。关于大气演化,本文首先描述了大气成分的演化历史,然后简述了影响大气成分演化的三个基本过程：大气逃逸、两次大气氧含量突然增加、碳酸盐-硅酸盐循环及其对气候系统的负反馈作用。两次全球性的冰川期分别发生在古元古代（距今24亿～21亿年）和新元古代（距今8亿～5.8亿年）,文章简述了其成因以及相关的气候模拟结果。暗弱太阳问题是地球历史气候演化的一个经典问题,论文简要地综述了一些最新的研究成果和观点。     

淮河流域水文极值预测模型研究

为探索气候变化影响下水文极值的非平稳性和预测方法,建立了水文极值非平稳广义极值（GEV）分布的统计预测模型。利用1952-2010年淮河上游流域累计面雨量和流量年最大值资料、同期500 hPa环流特征量资料以及17个CMIP5模式对环流特征量的模拟结果,筛选出对水文极值影响显著的年平均北半球极涡强度指数作为GEV分布参数的预测因子。分析了在RCP2.6、RCP4.5和RCP8.5情景下2006-2050年淮河上游流域水文极值对气候变化的响应。结果表明,10年以下与10年以上重现期的水文极值在非平稳过程中呈现前者下降而后者上升的相反变化趋势;多模型预测的集合平均在未来情景中均呈现上升趋势,情景排放量越大增幅越大,重现期越长增幅也越大。与极值的常态相比,极值的极端态更易受气候变化影响。     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.