Statistical methods are employed to assess the extent to which measurements of temperature using downward looking infrared thermometry (T₀) are indicative of the effective boundary between the air and the subsurface environment. An effective interfacial surface temperature (T_e) is determined from consideration of in-air (T_a) and subsurface (T_s) temperature data, being that which best satisfies the multi-media (air and soil) flux relationships. Using data obtained in studies conducted in Ohio in 2015, it is shown that during the daytime measured values of T₀ exceeded T_e by an amount reaching a near-noon maximum of about 2 °C when the crop (maize) was fully grown. Night-time observations indicated a near equality of T₀ and T_e, although often equality appears threatened by the presence of strongly stable layers in air near the surface. Ramifications of the observed differences are discussed, with particular attention to implications regarding determination of the thermal roughness length associated with the sensible heat flux.

使用统计方法来评估使用向下看的红外测温法（T ₀）进行的温度测量表明空气与地下环境之间的有效边界的程度。有效界面表面温度（Ť _ë）从考虑的确定在空中（Ť_一个）和次表面（Ť_小号）的温度数据，在于它最好满足多媒介（空气和土壤）通量的关系。根据2015年在俄亥俄州进行的研究获得的数据，表明白天的T ₀测量值超过了T _e当作物（玉米）完全长大时，达到接近午夜最高约2°C的量。夜间观察表明，T ₀和T _e几乎相等，尽管经常看起来相等是由于地表附近空气中存在高度稳定的层而受到威胁。讨论了观察到的差异的后果，特别注意与确定与显热通量相关的热粗糙度长度的含义。