Measurement of Soil Heat Flux Using a Thermo-module

Abstract

Measurement of soil heat flux using a thermo-module was examined. The measuring principle is almost the same to a traditional heat flux plate method, however, the measurement accuracy of the temperature difference of the thermo-module is much higher than that of the traditional thermo-pile. It was considered that the utilization of thermo-module allowed to measure the soil heat flux accurately even under the soil layer of small temperature gradients. Relation between the thermo-module output and one-dimensional steady heat flux was examined in agar-gel. As a result, the thermo-module output was proportional to the heat flux in a wide range. Using this relation, the soil heat flux in a field was determined. In order to confirm the reliability of the thermo-module method, the heat storage flux in soil layer was compared between the thermomodule method and the calorimetric method. Both results corresponded closely. These showed that the thermo-module method was effective as the heat flux meter.