Pho- 
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Dort- 
WIND-INDUCED MICROCLIMATIC DIFFERENCES DETECTED FROM 
THERMAL SCANNER DATA 
Wilfried Nübler 
Geographisches Institut I der Universitat Freiburg 
Introduction 
The climatological interpretation of thermal scanner data is a 
long and intricate story. Since more advanced remote sensing 
methods have been available, the solution of climatological 
questions has always been looked upon as one possible and pro- 
mising application of the new techniques [Mattsson 1967, Lorenz 
1973a]. It is intricate, in that there is still a good deal of 
controversy on whether at all, or to what degree, remotely 
sensed data of the earth's surface can be useful for the clima- 
tologist [Lorenz 1973b]. This is especially apparent in the 
case of small scale or micro- and mesoclimatological studies. 
However, certain applications at the global level, e.g. cloud 
cover monitoring, are now standard methods [Lenhart 1978]. 
The main reason for this reserved attitude still prevalent among 
climatologists is not a technical but a principal one: Thermal 
scanning means recording the radiation emitted by the earth's 
surface, while the climatologist is concerned with the air layer 
above this surface. Although it is evident that the boundary 
layer of the atmoghere is influenced by the underlying surface, 
interrelationships are so complex that unequivocal interpretation 
is, in general, not possible. 
It is the purpose of this paper to demonstrate that under certain 
conditions microclimatic differences can definitely be deduced 
from thermal scanner data. The possibilities and limitations of 
tracing cold air in thermal images were covered earlier [Nubler 
1978]. This paper concentrates on two examples of the effect of 
wind action as seen in thermal images. 
Material and methods 
All material referred to is taken from the data obtained from 
the German Remote Sensing Project (Deutsches Flugzeugmefpro-