stereographic cloud analysis from Apollo 6 photographs over a cold front

TLDR: In this paper, the three dimensional cloud structure over a strong cold front in the southeastern United States on 4 April 1968 was analyzed using three-dimensional stereo images from the Apollo 6 mission, and the analysis extended from near Tyler, Texas, eastward to the Georgia coast.

Abstract: Twenty-three overlapping photographs from the Apollo 6 mission were stereographically analyzed to determine the three dimensional cloud structure over a strong cold front in the southeastern United States on 4 April 1968. The analysis extended from near Tyler, Texas, eastward to the Georgia coast. Four major cloud regions were observed: a zone of altocumulus behind the front, a vigorous thunderstorm complex along and just ahead of the front, a chaotic region of multilayer clouds for a few hundred kilometers east of the thunderstorms and a large region of cloud streets parallel to the surface winds near the coast. The cloud top altitudes in the thunderstorm complex were extraordinary, reaching a maximum height of 22.375 km, whereas the tropopause was located at 12–13 km and the maximum tops reported by radar 30 min before the Apollo pass were at 12.5 km. An area of approximately 2 × 104 km2 was covered with maximum tops of ⩾ 18 km. The accuracy of the stereographic technique was confirmed with cloud top al...