scope:

Climate is defined as the state of the atmosphere in a region over a certain period of time. As far as independent climate characteristics develop there, one speaks, in terms of this guideline, of urban climate in urban and settlement areas and of site-related climate in the vicinity of the site of an installation, etc. In this way, regional, geographical and local climate can be distinguished from large-scale or global climate.

For investigations regarding the site-related climate or the climate in small areas with strong spatial differentiation, mobile measurements are preferably taken into account, since stationary networks cannot be used in a sensible and economically reasonable way because of the multitude of required measuring stations. Results of remote sensing methods only have limited information content for this purpose because they only provide the surface temperature in the e.g. thermal scope.

In terms of this guideline, mobile climate measurements are measurement methods in which the sensor or sensors are not stationary, but they are moved through a suitable investigation area on a mobile mounting unit.

If the sensors are continuously driven during the measurement run, one speaks of continuous measuring operation. If they are only driven at certain points of the terrain or only within certain time intervals, one speaks of discontinuous measuring operation (see also Section 5).

Investigation objectives of mobile climate measurements include spatial distributions of the relevant climate variables in the area under investigation. Depending on the respective objective, these can be:

• air temperature at given times of day or year

• air humidity

• flows

• solar and terrestrial radiation

• derived quantities like mugginess or other bioclimatic variables

• delimitation of areas with uniform microclimatic characteristics (climatopes)

These spatial distributions can serve to describe and explain the underlying local circulation systems (see below). They can also be used to assess the climatic effects of planned changes or modifications to the landscape. Table 1 gives an overview of the applications of mobile climate measurements by way of examples.