探空湿度测量太阳辐射误差时空分布特征研究

The Research on Spatial and Temporal Distribution of Solar Radiation Error of Radiosonde Humidity Sensor

针对太阳辐射加热引起探空湿度测量产生偏干误差,采用流体动力学（CFD）软件对探空湿度测量模型施加对流-太阳辐射耦合热边界条件,模拟湿度传感器上的温度场分布,结合电容湿度传感器的工作原理和相对湿度的定义,提出了太阳辐射偏于误差修正的数值分析模型.数值分析结果表明：随着海拔高度的升高,湿度测量的太阳辐射误差随之增大;在不同的地区实施探空湿度测量,太阳辐射误差随季节变化曲线与纬度密切相关;在白天当地时间6 ～18点之间施放气球,太阳辐射误差随时间先增加再减小,当地时间正午12点时达到最大.为探空湿度测量太阳辐射误差修正的时空分布特征的研究提供了一种新的方法.

In order to correct the dry bias caused by solar radiation heating in the relative humidity（RH） measurement,the computational fluid dynamics soft is applied to simulate the temperature distribution of the humidity sensor under the boundary condition of fluid-olid coupled heat transfer,and then combining with the work principle of humidity sensor and the definition of RH,a numerical analysis model is put forward for correcting solar radiation dry bias （SRDB）.The results of numerical analysis show that the SRDB is nonlinearly increased with the altitude.The simulation data also show the relations between the SRDB and the day are closely related to the latitude of the measurement locations.From sunrise to sunset,the SRDB increases firstly and then decreases with time,and which reaches the maximum at the noon of the local time.A novel approach is presented for investigating the spatial and temporal distribution of the SRDB correction in the humidity measurement.