No abstract

Our analysis of the Venera 8 measurements yields equatorial morning terminator horizontal and vertical winds that are similar in a number of respects to the winds we obtained from our analysis of the Venera 7 measurements. The lower boundary of the horizontal retrograde ‘4‐day’ wind is defined by a 50–60% decrease in wind speed in the vicinity of 44 km, and there exists a retrograde wind ‘plateau’ of 15‐ to 40‐m/s winds extending from 40 km down to the vicinity of 18 km, where the winds decrease rapidly to the order of 0.1 m/s near the surface. Updrafts of 2–5 m/s exist in the vicinity of 20–30 km and are apparently associated with a slightly superadiabatic lapse rate.

We have performed a detailed analysis of the published Venus IR maps and have obtained a number of new results. The global contour map of the average temperature variations in the vicinity of 6120 km reveals the existence of saddle points along the equator at dawn, at noon, and just before sunset. The hot spots observed at 4:30–4:40 A.M. at 65°–68°S latitude appear to be in the vicinity of the coldest region from which the 8‐ to 14‐µm emissions originate. At large earth zenith angles the limb darkening curves show a hump which is attributed primarily to a single patchy haze layer in the vicinity of 6123 km and with a thickness of the order of 3 km. We obtain an average IR source region temperature of 250°K at the equator. At the poles the same altitude region is 8°K cooler.

Nitric oxide has been measured in situ between 38.4 and 29.8 km by a new technique, photoionization mass spectrometry. Data indicate a peak mixing ratio of 5.7 ± 0.35 ppbv at 37.5 km and only 0.2 ± 0.2 ppbv at 32.8 km with a sharp gradient in concentration between 33 and 34 km. Simultaneous in‐situ measurements of the ozone concentration show no significant feature at that altitude. The rapid decrease in mixing ratio is not predicted by current theory.

Profiles of atmospheric pressure, density, and temperature for the region from 20 to 110 km above Fort Churchill, Canada, were computed from the data obtained during a single fall‐day rocket flight. The temperature profile had a major maximum at 58 km, a secondary maximum at 82 km, and several minor maxima in the region from 20 to 55 km. During the same flight a horizontal‐wind profile was obtained in the region from 80 to 115 km. Average wind speed was 125 m/sec, and the maximum wind speed was 250 m/sec at 115 km. The method of measurement, the problems encountered, and the results are discussed. Methods are prescribed for the use of the pitot‐static tube for accurate synoptic atmospheric structure measurements from 20 to 80 km and for the measurement of semidiurnal pressure variations in the same region.