Improvements in radiosonde humidity profiles using RS80/RS90 radiosondes of Vaisala
Improvements in radiosonde humidity profiles using RS80/RS90 radiosondes of Vaisala
复制标题
使用维萨拉 RS80/RS90 无线电探空仪改进无线电探空仪湿度剖面
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
T. Naebert
中科院分区：
文献类型：
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作者：
U. Leiterer;H. Dier;T. Naebert
自由大气中相对湿度的精确测量仍然缺乏，特别是对于低于-30 °C的温度。尽管存在这些问题，但气候和天气研究以及业务天气预报都需要精确的湿度测量。在本文中，我们使用Vaisala商业制造的无线电探空仪RS 80/RS 90进行精确湿度测量。本文首先介绍了相对湿度的物理性质和定义，以方便不熟悉湿度测量的读者。讨论了三种常用蒸汽压公式的差异。其次，对目前广泛使用的RS 80无线电探空仪的现状进行了总结，指出了存在的问题。之后，我们建议使用维萨拉的新型H-Humicap聚合物传感器引入所谓的标准化频率，该传感器允许在固定校准点0%和100%处精确测量相对湿度，相对于纯相水的理论精度为±0.05%。与标准化频率有关的主要发现是，两个频率之差（从聚合物容量导出）的商在其数值上等于相对于水的相对湿度，即水蒸气分压比。人们得到这个比率如下：加热频率（相当于0%相对于。湿度）减去测量频率除以加热频率（相当于0%相对湿度）。湿度）减去100%相对测量频率。湿度（常压和室温）。基本结论是，在无线电探空仪从地面上升到大约100百帕的压力和在例如+30 ° C到-70 ° C的温度范围内，使用加热频率应用这些标准化频率。最后给出了四个RS 80/RS 90双飞的例子，分别显示了无云、多云和结冰（仅RS 80）的情况。此外，第四个例子显示了激光雷达设备的后向散射轮廓。这两幅图清楚地表明，使用标准频率法，H-Humicap比A-Humicap可以测量更好的湿度数据。
Accurate measurements of relative humidity in the free atmosphere are still lacking, especially for temperatures below-30°C. Despite these problems, precise humidity measurements are needed for climate and weather research as well as for operational weather forecasting. In this paper we open new variants for exact humidity measurements using the commercially manufactured radiosondes RS80/RS90 of Vaisala. At first we give some remarks to the physical nature and the definition of relative humidity for readers who are not familiar with humidity measuring. The differences of three common vapor pressure formulas will be discussed. Second the state of the art of the widely-used RS80 radiosondes summarizes the problems which still exist. After that follows our proposal to introduce so-called standardized frequencies using a new H-Humicap polymer sensor of Vaisala which allow exact relative humidity measurements at the fixed calibration points 0% and 100% within the theoretical accuracy ±0.05% with respect to water in the pure phase. The major finding in connection with the standardized frequencies is that the quotient of two frequencies' differences (derived from polymer capacities) in its numerical value is equal to the relative humidity with respect to water, that is the water vapor partial pressure ratio. One gets this ratio as follows: Heated frequency (is equivalent to 0% rel. humidity) minus measuring frequency divided by heated frequency (is equivalent to 0% rel. humidity) minus measuring frequency of 100% rel. humidity (at normal pressure and room temperatur). The essential conclusion is the application of these standardized frequencies using heated frequencies during the radiosonde ascent from the ground up to a pressure of about 100 hPa and over a temperature range of e.g. +30°C up to -70°C. Lastly four examples of RS80/RS90 twin flights are presented showing the cloudless, the cloudy and the icing (only for RS80) case. In addition the fourth example shows the backscattering profile of a LIDAR-equipment. These twin fligths clearly show that better humidity data can be measured with the H-Humicap than with the A-Humicap using the standardized frequency method.