DIURNAL VARIATION IN STRATOSPHERIC TEMPERATURES AND HEIGHTS REPORTED BY THE U.S. WEATHER BUREAU OUTRIGGER RADIOSONDE

Abstract

The diurnal change in temperature and height measured by the new U.S. Weather Bureau outrigger radiosonde at and above 100 mb. has been determined from pairs of successive radiosonde observations taking place in daylight and darkness. Analyzed graphs of the change as a function of solar elevation angle are presented. For a given solar angle, the observed diurnal variations are found to be larger with afternoon daylight than with morning daylight. Furthermore, values computed for Plateau stations with afternoon daylight are particularly large. Use of the white 50-mil rod thermistor with outrigger mounting has radically improved the compatibility of reported temperatures and heights at adjacent stations, primarily because the radiational temperature error has been reduced by a factor of about two to four. The observed diurnal variations measured by this new instrument are comparable with those of the military outrigger radiosonde, allowing for the slightly smaller thermistor of the latter.