NASA - National Aeronautics and Space Administration
  
00-050
Jovian System Data Analysis Program


Cover Page/Proposal Summary

ROSS-99    NRA 99-OSS-01

Date Due: 5/5/99

NASA PROCEDURE FOR HANDLING PROPOSALS

This proposal shall be used and disclosed for evaluation purposes only, and a copy of this Government notice shall be applied to any reproduction or abstract thereof. Any authorized restrictive notices that the submitter places on this proposal shall also be strictly complied with. Disclosure of this proposal for any reason outside the Government evaluation purposes shall be made only to the extent authorized by the Government.

Proposal Type: New Proposal

Proposal Category: Satellites and Rings

Major Equipment Proposal? No

Do you intend to submit an Education/Public Outreach (E/PO) proposal? No

Proposal Title:
Multi-Wavelength Modeling of Hot Spots on Io

Abbreviated Proposal Title:
Modeling Hot Spots on Io

Principal Investigator:
Dr. Robert Howell
Dept. of Physics & Astronomy
University of Wyoming
Laramie, WY 82071
Phone: 307-766-6296   Fax: 307-766-2652   E-mail: rhowell@uwyo.edu

SignatureDate
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Co-Investigators and Collaborators:
NONE


Proposal Summary:

Galileo NIMS and SSI observations provide frequent measurements of the thermal flux from individual hot spots on Io, but except for limited PPR observations, Galileo will not obtain measurements at wavelengths longward of 5 microns where most of the hot spot energy is emitted. Recently developed flow models indicate that such mid-infrared measurements are crucial to understanding the nature of the flows. For example the data analyzed to date suggest two very different classes of activity: one having only only a small hot area which is rapidly resurfaces on times scales of a day or less , while the other accumulate large areas of cooling flows over time scales of months. The distinction between these types of activity is best seen in the mid-infrared, and measurements here are crucial to determining flow volumes and total hot spot energetics. The best existing data set on long wavelength emission from individual hot spots is the one from the Voyager IRIS instrument, but the long time gap between Voyager and Galileo presents obvious difficulties in using this data. However I have recently developed techniques for applying the ground-based Jupiter-Io occultation technique at 10 microns, and am now obtaining such measurements of the mid-IR flux from individual hot spots. In addition, under an existing Planetary Astronomy grant I am obtaining very frequent short wavelength occultation and eclipse measurements which sample the ?instantaneous? eruptive rates with time resolution considerably higher than Galileo. I propose to apply the new flow models to the combined Galileo/ground-based/Voyager data set to classify modes of activity for the various hot spots on Io. The combined data set provides the wavelength and temporal coverage needed to determine the nature of the eruptive activity at individual sites. The result of this work will be a classification of different types of hot spots and constraints on the heat flow from different regions of the satellite.