Further aspects on the diurnal temperature variation at the surface of the earth

From a number of independent clear-sky observations of global radiation and temperature at the surface of the earth, typical values are derived for the diurnal variation of these elements for certain specified lengths of the day. An attempt is made to relate the typical variation of radiation with that of surface temperature by the aid of a formula recently suggested by the author. The agreement is good and the constants used in the formula resemble those previously used by the author.

Depending on the actual conditions (type of soil, humidity gradient in the air, etc.) various combinations of the two constants should be used in the formula. It is demonstrated how the choice of constants affects the amplitude and phase lag of the temperature curve. Also discussed is the possibility of incorporating turbulence effects in the formula.