ground 
Hei- 
the 
ture 
om- 
2asured 
ly 
lotted 
jpi- 
1 
ler- 
Cac 
) a.m. 
Heat flow and soil moisture 
Basics 
The relations between heat transfer and soil moisture can be described 
as a problem of three strata: heat flow through the soil, heat flow 
from soil surface to the measured surface (surface of vegetation) and 
the radiation from the atmosphere near to the measured surface. 
The quantity of heat AQ, which flows through a soil volume with a 
quantity of solid matter Un and of water m with the corresponding 
specific heat capacities c, and -— with the bottom and top tempera- 
B 
tures Ts) and Toys is for a time interval At given by the equation: 
(1) AQ / At = (egg * ew x AT, 
A certain quantity of AQ of the soil is transported from the upper- 
most strata of soil to the measured surface (vegetation and/or soil) 
by radiation. This part of AS per diameter q is given by 
: de 
(2) AS 7? At = 5 x gx (Tg Tg ) 
As Tg also contains the influence of the atmosphere in equation (2) 
there exists a connection between soil temperature, surface tempera- 
ture and backscattering of the atmosphere. 
Heat flow during various seasons 
Corresponding to the equations (1) and (2) AQ and AS were calculated 
from radiometer data acquired in 1976 at Kochel Moos area. The curves 
in fig. 4 are valuable for night times between 9 p.m. and 6 a.m. 
During this interval of time temperature decreased from -0,1 m to 
*0,2 m (see fig. 3). 
Although unregular the curves of fig. 4 show a characteristic asyme- 
tric shape. The values calculated from measurements can be smoothed