Mesospheric ozone measurements during a solar eclipse

A rocket-borne ozonesonde that utilizes the chemiluminescent principle for the measurement of ozone concentration in the upper atmosphere has been developed. The sonde is deployed in the mesosphere by a small meteorological rocket (Arcas), and ozone concentration is measured as the instrument descends on a drag parachute. This instrument was flown during and before the total solar eclipse of November 12, 1966, at Tartagal (22°32′S, 63°50′W), Argentina, with the cooperation of scientists from that country. Ozone was monitored as the sonde passed through the total eclipse shadow beween 60 and 54 km and registered a higher concentration than the sounding made a day earlier at about the same time. A decrease in the ozone concentration was noticed as the sonde emerged from the shadow of the total eclipse. Ozone concentration at 57 km during total solar eclipse was measured to be 3.7 × 10−3 cm km−1 as compared with 1.4 × 10−3 cm km−1 measured a day earlier at the same altitude. No marked effect on the ozone concentration in the upper stratosphere was noted during the partial eclipse conditions under which that region was observed.