Project Halo: The annular solar eclipse of 1994

Abstract

Solar eclipses are most often described in terms of their astronomical significance, but they also provide a unique opportunity to study various atmospheric phenomena. Because eclipses are brief and usually occur over oceans or remote land surfaces, these opportunities are quite rare. Thus, a comment about the solar eclipse of May 20, 1947, remains as valid today as when it was published nearly half a century ago: “Something also can be learned about how the upper levels of the Earth's own atmosphere are affected by the Sun's rays, by noting what happens in the atmosphere when those rays are cut off during an eclipse” [Colton, 1947].The annular eclipse of May 10, 1994, will provide a significant opportunity for observers in the United States since its centerline will sweep from New Mexico to Maine (Figure 1). I have begun Project Halo to encourage observations of this eclipse, which will be the last visible from the continental United States until 2017.