Superpressure Balloon Flights in the Tropical Boundary Layer

Abstract

Two series of quasi-constant-level pressurized balloons have been flown within the tropical planetary boundary layer, preliminary to a larger experiment for exploring the low-level flow over the Indian Ocean. The first flight series from a South Pacific island indicated a very short life expectancy of the equipment due to the high probability of the vehicle being overloaded by rain drops or dew and the catastrophic effect of immersion. A second series of flights from Ascension Island in the South Atlantic was performed to test a new and completely self-enclosed balloon design, as well as a metalized reflecting screen for radiative control of the envelope temperature. This new design demonstrated acceptable vertical stability, thus proving the feasibility of long-duration quasi-horizontal balloon flights at levels as low as 500 m above the sea surface.