Overflatestemperaturen

Overflatestemperaturen, commonly referred to in meteorology and remote sensing as surface temperature, is the temperature of the outermost layer of a surface that is in direct contact with its surroundings. On Earth, it denotes the temperature of ground, vegetation, water, or built surfaces at or near the surface, and is distinct from air temperature measured a few meters above the surface.

Surface temperature can be measured by contact thermometers placed on the surface, infrared radiometers, and satellite instruments that infer temperature from emitted infrared radiation. Reported values are usually given in degrees Celsius or kelvin. Emissivity of the surface and atmospheric conditions influence infrared measurements and must be accounted for in data processing.

Determinants and variability: Surface temperature is governed by solar input, surface properties (albedo, moisture, roughness, thermal inertia), and heat exchange with air. It shows strong diurnal and synoptic variability; land surfaces can heat up quickly in sun and cool rapidly at night, while water bodies moderate temperature changes. Urban areas often exhibit higher surface temperatures than surrounding rural land due to heat absorption and reduced cooling (urban heat island effect).

Applications: Land surface temperature (LST) is a key variable in climate studies, weather forecasting, agriculture, water resource management, and urban planning. In remote sensing, LST data from MODIS, Landsat, and other satellites are used with land cover maps to study energy balance and climate change. Data quality depends on sensor calibration, atmospheric correction, and surface emissivity estimates.

See also: Land surface temperature, sea surface temperature, air temperature, urban heat island.