Izvleček
Članek obravnava periodično spreminjanje temperature tal, katerih površina se čez dan segreje, ponoči pa ohladi oziroma se poleti segreje in pozimi ohladi. Pri tem so globlje v tleh spremembe temperature vse manjše, tako da je na neki globini temperatura konstantna. Kolikšna je ta globina, je odvisno tako od lastnosti tal kot od tega, ali gre za krajše, dnevne cikle ali za dolge, letne cikle. Lastnosti tal – toplotna prevodnost, specifična toplota in gostota tal – skupaj tvorijo t. i. toplotno difuzivnost (imenovano tudi temperaturna ali termalna difuzivnost). Temperaturne spremembe pa se z globino ne le manjšajo, ampak tudi čedalje bolj časovno zaostajajo.
Abstract
How Does Soil Temperature Change During the Day and Throughout the Year?
This paper considers the periodic variation in soil temperature, where the surface warms up during the day and cools down at night or warms up in summer and cools down in winter. The greater the depth below the ground surface, the smaller the shifts. It follows, then, that the temperature remains constant at a certain depth. The depth depends on both, the properties of the soil as well as on whether there are short, daily cycles, or long, annual cycles. Soil properties, namely, thermal conductivity, specific heat, and soil density form the so-called thermal diffusivity. With depth, not only do the magnitudes of temperature changes decrease, but they also lag behind.