检查曲管地温表安装角度的一种方法

《地面气象观测规范》规定曲管地温表的安装要求是表身与地面成45°夹角,并确定其安装及每月定期检查时所允许的误差范围为土5°。即表身与地面夹角在40°～50°之间均在允许范围之内。为了保证曲管地温表安装准确,现介绍一种简单易行的检查方法,供大家在安装及定期检查时参考。 如图:设表身与地面的夹角为,温度表伸出地面的长度为,温度表顶端到地面的垂直高度为。根据规范要求,应为45°,其允许范围为40°～50°,的长度对于一支温度表来说是可实测得到     

积雪时地面3支温度表的安置状态

使用机制报表程序预审气表 - 1数据中 ,有时发现冬季积雪时 ,计算机经常提示地面最高、最低温度有疑误。这是由于积雪时地面 3支温度表安置状态不同造成的。因此 ,在安置 3支温度表时应注意 :①温度表应水平安置在未被破坏的雪面上 ,避免安置不水平使温度表受重力影响而导致温度示值不准。②安置地温表前 ,一定要用干净的软布擦净表身及球部所粘泥土 ,避免因泥、雪不同的导热率使温度不准。③加强巡视 ,每小时都要认真察看 3支温度表的安置状态 ,尤其是在积雪融化时 ,发现表身下陷或悬空应及时重新安置。④要注意保持地温场雪面状态 ,每次移…     

地面气象观测仪器的清洁与维护

简单介绍南雄气象站在日常工作中对地面气象观测仪器的清洁与维护的一些做法,即在清洁维护仪器时要注意时间、顺序、天气条件及容易疏忽的事项等。     

一种深层地温的推算方法

根据热传导方程,利用差分方法计算导温系数,并用逐层下移温度初始场技术来推算深层各月平均地温,并通过计算个例加以对比分析。结果表明,该方法简单实用,计算精度有较大提高,效果令人满意。     

保持地温场与观测场的整个地面相平

1　问题的提出如果台站的地温场水土逐渐流失 ,造成低于整个观测场地面的低洼地 ,就不符合《地面气象观测规范》的要求 ,《地面气象观测规范》要求 :地温场的地表应疏松、平整、无草 ,并与观测场整个地面相平。但是 ,这个问题有些台站却未重视 ,使长期积累的地温资料的代表性、比较性、资料序列的均一性受到难以弥补的损害。这无疑将降低这些资料的使用价值。为了证明地温场低于观测场的整个地面 ,会产生什么影响 ,我们在 2 0 0 1年 5月5～ 1 5日前后的 2 0时对 0 cm(地温场低于观测场约 5cm)做了对比观测 ,见表 1。表 1　地温场和观测场观…     

地面温度表与曲管地温表的不规范安装及误差分析

通过实际对比观测，分析了地面温度表与曲管地温表几种不规范安装与使用所造成的误差，明确了以上两种温度表使用与维护应注意的事项。     

Linux的简易安装

Ｌｉｎｕｘ是一套免费使用和自由传播的类Ｕｎｉｘ操作系统 ,是Ｌｉｎｕｓ和Ｍｉｎｉｘ的混合称呼。它具有源代码公开、优良的内存管理、免费的操作系统和应用软件、支持各种应用软件等特点 ,Ｌｉｎｕｘ包括最底层的内核、第二层的服务器 /桌面和第三层的ＸＷｉｎｄｏｗ窗口系统和应用软件。1　Ｌｉｎｕｘ的优点1 1　多任务操作系统多任务系统就是同时可运行多个程序 (或进程 )的系统。例如 ,系统可以打印文档、复制文件、拨号到Ｉｎｔｅｒｎｅｔ,而用户还能自如地处理程序中的输入。这些 ,Ｗｉｎｄｏｗｓ95都不能完全胜任 ,只有Ｌｉｎｕｘ…     

四川省地面气象资料统计方法及产品简介

本文简明扼要地介绍了地面气象资料中常用要素的日、旬、月、年值的统计和缺测记录处理方法,对各要素原始观测数据和统计产品中常见的特定值做了较详细的说明。作者全面地介绍了四川省目前广泛用于服务的气候资料产品的文件类型、数据内容和数据格式。     

四川省地面气象资料统计方法及产品简介

本文简明扼要地介绍了地面气象资料中常用要素的日、旬、月、年值的统计和缺测记录处理方法,对各要素原始观测数据和统计产品中常见的特定值做了较详细的说明.作者全面地介绍了四川省目前广泛用于服务的气候资料产品的文件类型、数据内容和数据格式.     

建筑工地的防雷保护措施

随着经济建设的发展各类楼房建成加快,在施工时间,由于建筑工地的起重机,卷扬机,手脚架等在雨季易发生雷击,加之建筑材料堆积,万一遭受雷击易发生大火,使施工人员生命会受到威胁,因此要重视建筑工地的防雷问题。     

怎样避免温度表读数误差

在观测中尤其是温度观测往往容易发生读数差错，为避免发生读数差５度１０度或颠倒零上零下这类差错《地面气象观测规范》特别强调：“注意复读即一般读数时须复读一次。”就是说，严格遵守操作规程，培养良好的观测习惯，观测前要巡视仪器，心中有数，观测时思想集中，视线要和水银柱顶端齐平，记录时细致认真，动作要迅速。是把读数差错降低到最小限度的基本保证。除此之外，在观测实践中我们体会到，自觉地做到以下三点，也可以有效地避免读数差错。１熟悉温度表的标度单位和刻度方法我们现用温度表有以５℃和２℃为标度单位，最小刻度为…     

Sensible heat flux measurements with a yaw sphere and thermometer

A yaw sphere has been designed that measures a quantity that is proportional to the vertical heat flux. The method is described, and some comparisons are given with measurements made with a three-dimensional pressure-sphere anemometer, in combination with a fast-response thermometer.     

A three-component sonic anemometer/thermometer system for general micrometeorological research

A three-component sonic anemometer/thermometer system has been developed. It employs single switched transducer pairs and the inverse timed pulse method to yield an absolute calibration. Microprocessor control and use of newly developed transducers give a very small parts cost. The path length of the instrument can be varied from 10 to 15 cm; output is available in digital or analog form. Temperature sensing, via a 5 Μm tungsten resistance element, is integrated into the digital system. Wind tunnel and field results have confirmed the success of the prototype and a set of operational instruments has been constructed.     

Intermittent wind close to the ground within a grass canopy

Wind speed was measured at a height of 1 cm above the ground and at several other heights in and above a canopy of tall fescue grass (Festuca arundinacea) using single hot-wire and triple hot-film anemometers. The plant area density in the canopy was concentrated close to the ground, with 75% of the plant area standing belowz=15 cm, wherez is height above the ground. The frequency distributions of horizontal wind speeds,s, were sharply skewed towards positive values at all measurement heights, but were most highly skewed near the ground where the coefficient of skewness ranged from 1.6 to 2.9. Above mid-canopy height, the frequency distribution ofs was described reasonably well by a Gumbel extreme value distribution. Average wind speed,S, decreased exponentially with depth into the canopy with an exponential scale length of abouth/2.8, whereh is the height of the canopy. Atz=1 cm, the value ofS was about 11% of the surface-layeru _*. The standard deviation of the fluctuations of the vertical and horizontal components of the wind speed also decreased exponentially with depth inside the canopy with a scale length of abouth/2.5.Inside the canopy, the Eulerian integral time scales for the vertical ( _w ) and horizontal ( _u ) components of wind speed were about 0.1 s and 1.0 s, respectively, and were approximately constant with height. Above the canopy, these time scales increased sharply and, atz=2.25h, _w and _u were approximately 1.0 and 3.0s, respectively. Turbulence length scales in the vertical and downwind directions, _u and _w ·U, respectively, were approximately 1 cm for heights between 1 to 10 cm above the ground inside the canopy, while atz=2.25h, they were about 55 cm and 277 cm. Relatively quiescent periods (lulls) in the air close to the ground were interrupted frequently by gusts. The frequency of occurrence of gusts appears to be correlated with the value of the local shear near the top of the canopy.     

An objective method for assessing representativeness of a station network measuring minimum temperature near the ground

The spatial auto-correlation of minimum temperature was analyzed for a topoclimatological station network in the Huleh Valley of Israel on radiation cooling nights, using the method of optimum interpolation. Only a few stations all of which are situated in a flat area along the longitudinal central axis, exhibited a distinct dependence of the auto-correlation with distance. These stations were less representative of the entire valley compared with sites close to the slopes.The more varied topography near the edges of the valley leaves its stamp on the auto-correlation field in two specific ways: