The numerical experiments of the orographic-dynamic effects upon the large scale motion of the atmosphere are made by use of the 3-level primitive equation model, in which the pressure coordinate system is adopted for the vertical. The experiments for the simple flows result in good agreement with the theoretical linear solutions, when the relatively low mountains are included. However, the results in cases where the high mountains are included, show that the flows eventually turn around the obstacles rather than pass over them, resulting in relatively small amplitudes. Other experiments are made for the baroclinic flows and the various mountains. From these, it is seen that a stationary trough appears on the lee side of the mountains in connection with relatively strong winds over the high and wide mountain barriers.
Two pyranometers were installed o n a helicopter to measure the upward and the downward fluxes of solar radiation at several levels in the lower atmosphere (500-7,000ft). The measurements were carried out at intervals of 1,000 ft between the heights 500 and 7,000 ft. The solar radiation absorbed by atmospheric constituents contained in each layer was obtained by the divergence of the net fluxes observed at several levels. The absorption due to water vapor was calculated by the formula given by Mügge and Möller using the available radiosonde data. Vertical profile of the absorption by aerosols differs from each other depending on the atmospheric conditions. The total absorption due to aerosols between 500 and 7,000 ft is about 17 per cent of the income at the top of the atmosphere in a hazy case and about 4 per cent in a clear case. From the absorption data the instantaneous heating rate of water vapor and aerosol absorption was calculated.
The conditions for a radiation source of a calibration device for pyrgeometers, which serve to measure the hemispherical (downward or upward) radiation flux, are discussed in some detail. A new calibration device for pyrgeometers meeting the conditions is Proposed. In this calibration device the water surface with numerous tiny water jets is employed as a radiation source. Some results of the calibration of the conventional pyrgeometers done by the present device are shown. The influence of wind field on the sensi t i vity of the conventional pyrgeometer, which is one of the important factors influencing measurement accuracy proper to the pyrgeometer, is examined by the present device. The sensitivity of the pyrgeometer was found to decrease with the increase of wind speed, and this decrease is larger in the "ventilation-type" pyrgeometer (Gier and Dunkle-type pyrgeometer) than in the "wind shield-type" pyrgeometer (Funk-type and Eko-type pyrgeometers). The sensitivities of pyrgeometers in a wind of 5m/sec decrease by about 20% and 11% from a windless case, respectively in the cases of wind perpendicular to the ventilation and of wind opposite to the ventilation for the Gier and Dunkle-type pyrgeometer, by about 7% for Funk-type pyrgeometer and by about 8% for the Eko-type pyrgeometer. Error in hemispherical radiation flux measured by the conventional pyrgeometers are discussed.