Soil Heat Flux Plate

The heat flux in the.

Soil heat flux plate.

A 6 5 increase in g m was also observed for plates treated with the same heat sink compound in a silt loam soil under field conditions. Model hfp01 soil heat flux plate 1. Implementation of the standard heat flux plate method at the bare soil site pairs of four types of heat flux plates were used table 2. Soil heat flux is important because its couples surface energy balance with energy transfer processes in the soil 64 and affects the soil surface 61 and soil temperatures.

If a heat flux plate is installed near the soil surface e g at 2 cm depth the plate might overestimate the soil heat flux by more than 20 as demonstrated by ochsner et al. Sites with heterogeneous media may require additional sensors. Introduction the hfp01 outputs a voltage signal that is proportional to the heat flux of the surrounding medium usually soil. The plates were installed in random order at 20 cm spacing along a north south transect.

Surface soil heat flux density g calculated using a heat flux plate at 0 02 m depth g 2 and the change in heat storage d s estimated from temperature change at 0 01 m depth versus g 2 alone using half hour data collected under 0 10 m tall cool season grass. Two sensors may provide spatial averaging. A thin layer of a thermal heat sink compound with λ 0 18 w m 1 k 1 greater than the plate λ m 1 0 w m 1 k 1 did not increase g m in a clay soil but increased g m by 6 in quartz sand. To convert this measured voltage to heat flux it must be divided by the plate s calibration constant.

The soil heat flux gz is commonly measured with passive heat flux plates but self calibrating plates or additional corrections are required to obtain accurate data. The soil heat flux at the bottom of this layer is also estimated rather than measured with a heat flux plate. 4 6 2 simple parameterizations in some climate and general circulation models the ground heat flux is simply neglected. These include heat flow distortion and ther mal contact resistance philip 1961.

However several potentially sig nificant errors may occurwhen using soil heat flux plates in the field. A unique calibration constant is supplied with each sensor. In an energy balance installation all sensors must be completely inserted into the soil face before the hole is backfilled. Disk called a heat flux plate or heat flow transducer to measure g sauer 2002.

And peng et al.