On the min–max estimation of mean daily temperatures

Abstract

Modern data analyses of hourly temperature records reveal the existence, in addition to the daily cycle, of multiple forcings of different frequencies. As a result the routine approach of estimating daily local mean temperature directly from the average of the minimum and maximum is heavily compromised. A simple dynamical model subjected to two periodic forcings of different frequencies, amplitudes and phases is solved analytically and shown to induce substantial deviations from the min–max method that depend crucially on the values of the parameters involved.