西藏科技

太阳辐射对百叶箱内的气温测量产生显著影响，也是决定气温读数准确性的关键因素之一。文章以百叶箱太阳辐射热效应的日变化及其季节差异特征为基础，应用CFD仿真技术，对我国地面常规气象观测中广泛应用百叶箱的太阳辐射热效应进行模拟，分析了日变化和季节差异对箱体的太阳辐射热效应的基本特征及其对箱体内部温度场分布的影响机理，以及百叶箱太阳辐射热效应与气温测量的关系。结果表明，百叶箱的太阳辐射热效应具有明显的日变化特征和季节差异，各季节产生热效应的侧面及其最大增温幅度都有明显不同；其侧面最大增温幅度可达4℃以上；各季节百叶箱内部中轴线上的辐射误差基本呈中部低、上下部高的“C”型分布特征，但日变化趋势有着明显的差异，夏季中轴线上的日变化最明显，在0.1至0.3 m高度上日变化可达到0.6℃，春（秋）季、冬季的日变化则相对较小，均在0.3℃以内；此外传感器上的辐射误差具有“M”型日变化特征，这种“M”型结构在夏季最为明显且最大误差超过了0.6℃。研究结果可为百叶箱结构优化以及气温订正模型的改进提供参考依据。

Solar radiation produces significant effect on the temperature measurement inside Stevenson screen,which is a key factor determining the accuracy of temperature readings. Focused on the daily and seasonal differences of thermal effect produced by solar radiation on Stevenson screen, this study employs CFD simulation technology to simulate the thermal effect produced by solar radiation on Stevenson screen widely used in conventional groundbased meteorological observatories It has analyzed the basic characteristics of the thermal effect of solar radiation in terms of daily and seasonal differences, the impact mechanism underlying in the internal temperature field distribution, as well as the relationship between the thermal effect of solar radiation and temperature measurement. The results show that the thermal effect produced by solar radiation on Stevenson screen exhibits significant daily and seasonal differences. The side panels that generate thermal effect and their maximum warming amplitude vary significantly across seasons, with the maximum warming amplitude on the side panels exceeding 4℃. The radiation errors along the central axis inside the Stevenson screen generally show a“C”-shaped distribution with lower value in the middle and higher value at the top and bottom across seasons, but the daily variation trend differs significantly. The daily variation on the central axis is the most pronounced in summer, reaching up to 0.6℃ at the height from 0.1 to0.3m, while the daily variation is smaller in spring(autumn) and winter, both within 0.3℃. The radiation errors in the sensors show an“M”-shaped daily variation pattern, with this structure being the most significant in summer,where the maximum error exceeds 0.6℃ in summer. The findings of this study can provide valuable reference for optimizing Stevenson screen structure and improving temperature correction models.