Optic-acoustic method of direct measurements of radiative heat influx in the atmosphere

An acousto-optic detector has been developed for measuring radiative heat fluxes in the atmosphere. Radiative fluxes enter an absorption chamber where they produce a pulsed heating of the air; pressure fluctuations induced by the heating are measured by a microphone. The device is calibrated using a black body and a gas mixture with a known integral function of absorption. Lab and field tests of the device have been carried out involving the measurement of long wave fluxes in the atmospheric boundary layer during superadiabatic and inversion stratification. Measurements in the short wave range are also shown to be possible.