Showing papers by "John Stansberry published in 1997"
TL;DR: In this paper, ground-based observations of Io's infrared thermal emission between February 1995 and May 1997 show several discrete brightenings for which we can constrain locations, fluxes, and durations.
Abstract: Ground-based observations of Io's infrared thermal emission between February 1995 and May 1997 show several discrete brightenings for which we can constrain locations, fluxes, and durations. Several of these were brief high-temperature events, with temperatures up to at least 1500 K, similar to but often smaller than the rare “outbursts” seen previously. Loki, Io's most powerful volcano, was relatively active before and probably during Galileo's December 1995 Io flyby, was faint during most of 1996, and began a major, long-lived brightening between February 20 and March 12 1997. Thermal emission was not seen from Ra Patera, site of an active plume in Galileo images. Major outbursts were seen on March 2nd and September 27 1995.
61 citations
TL;DR: In this article, the authors used a model of emission from lava flows to understand observations of two brightenings in 1996, caused by eruptions ≃ 3km² in extent, with eruptive rates of 104-106 mµs−1 and with maximum lava temperatures ≥ 1400 K.
Abstract: We monitored Io's volcanic thermal emission from 1.7 to 4.8 µm in 1995/96. The data reveal a number of brightenings when Io's thermal emission increased several-fold. We use a model of emission from lava flows to understand observations of two brightenings in 1996. The brightenings were caused by eruptions ≃ 3km² in extent, with eruptive rates of 104-106 m²s−1 and with maximum lava temperatures ≥ 1400 K. These events were probably lava lakes and/or fire fountains.
58 citations
TL;DR: A stellar-occultation light curve for Triton shows asymmetry that can be understood if Tris's middle atmosphere is distorted from spherical symmetry as mentioned in this paper, which could be caused by an unrealistic internal mass distribution or highly supersonic zonal winds.
Abstract: A stellar-occultation light curve for Triton shows asymmetry that can be understood if Triton's middle atmosphere is distorted from spherical symmetry. Although a globally oblate model can explain the data, the inferred atmospheric flattening is so large that it could be caused only by an unrealistic internal mass distribution or highly supersonic zonal winds. Cyclostrophic winds confined to a jet near Triton's northern or southern limbs (or both) could also be responsible for the details of the light curve, but such winds are required to be slightly supersonic. Hazes and clouds in the atmosphere are unlikely to have caused the asymmetry in the light curve.
16 citations