Temperature gradient of the natural water surface thermal radiation

Abstract

The dependence of the thermal radiation of natural water on its kinetic temperature in the temperature range of 7-70 degrees Celsius was experimentally investigated. The measurements were carried out on an experimental installation FPK-11 with a thermocouple as a receiver of integral thermal radiation. The measurements were carried out outdoors at an ambient temperature of about zero degrees Celsius. The water temperature was measured by a contact thermometer immersed in the water column. In the temperature range of 28-40 degrees Celsius, a decrease in the thermal radiation of water was revealed with an increase in its kinetic temperature. A “hump” of thermal radiation in the range of 7-40 degrees with a drop in thermal radiation of about 10% of the maximum was revealed. The value of the contrast in the studied temperature range makes it possible to detect thermal contrasts of the hydro objects surfaces. It was proposed to use the thermal radiation of pure water as a reference for measurements. The conditions of practical use of temperature dependences of the thermal radiation of water for environmental monitoring of water surfaces are proposed.