Errors in Land Surface Temperature Measurements from Stem Thermometer

Abstract

Errors are examined in land surface temperature measurements from stem thermometer. The purpose here is to estimate the errors in the temperature data observed at meteorological stations of China. One stem thermometer is only put on the soil surface, and the other stem thermometer is half buried in the soil. The actual soil surface temperature is measured by using a thermocouple.The temperature of stem thermometer is almost equivalent to the soil surface temperature if the under half of the stem thermometer is buried. However, the temperature by the stem thermometer is slightly lower when the soil surface temperature is extremely high.If the stem thermometer is only put on the soil surface, the temperature by the stem thermometer is almost always lower than the soil surface temperature (sometimes 7—8°C lower). This temperature difference is explicable by the heat budget of the stem thermometer. That is, the effect of heating by the solar radiation is less than that of cooling by the sensible heat transport from the thermometer to the air.These results give the possibility of using the stem thermometer data for various quantitative analyses.