JOVIAN SYSTEM DATA ANALYSIS PROGRAM PROPOSAL SUMMARY

The goal of this program is to determine the temperature structure, the properties of large particles in the ammonia clouds, and some aspects of the dynamics of Jupiter's atmosphere from filtered radiometry taken by the Galileo Photopolarimeter (PPR) experiment. The result of the proposed research is intended to complete as far as possible the analysis of PPR filtered radiometric data obtained during the primary mission. Over the next two years, we will determine the temperature field of Jupiter over regions of the planet observed by the PPR experiment. These include small and medium features observed synoptically with the other remote sensing instruments, larger regional maps, and pole-to-pole latitudinal scans. The thermal wind shears derived from these temperature fields will provide information about how the winds change with altitude and will complement cloud-tracked wind measurements made by the Galileo SSI camera. Long-wavelength measurements will be used to determine the opacity of the ammonia condensate cloud and with radii greater than ~1 micron. A comparison with earth-based data obtained and analyzed independently will further constrain the size of particles in the ammonia clouds. We will also model the dynamics of a large-scale, quasi-stationary wave observed to be meridionally trapped in the retrograde jet associated with the North Equatorial Belt. This study will yield new results about the vertical structure and origin of this class of wave. The following articles published by the proposers show the expertise gained in analyzing the data obtained in the primary mission. G. S. Orton, J. R. Spencer, L. D. Travis, T. Z. Martin, L. K. Tamppari, 1996. Results of the Galileo Photopolarimeter/Radiometer on Jupiter and the Galilean Satellites. Science 274, 388-391. G. Orton, B. Fisher, J. L. Ortiz, P. Yanamandra-Fisher, K. Rages, R. Howell, B. Klebe, R. Stencel, P. Drossart, J. Lecacheux, F. Colas, E. Frappa, C. Hernandez, D. Parker, I. Miyazaki, S. Stewart, J. Stansberry, J. Spencer, W. Golisch, D. Griep, M.-C. Hainaut, R. Joseph, C. Kaminski, J. Banjevic, C. Connor, S. Hinkley, M. Marinova, B. Marriage, E. Noe Dobrea. 1996. Characterization of Jupiter's atmosphere from Galileo and earth-based observations during the Ganmede-1 and Ganymede-2 orbit encounters. Bull. Amer. Astron. Soc. 28, 1137. G. Orton, T. Martin, T. Tamppari. O. Liepack, B. Fisher, J. Friedson, M. Ressler, R. Yanamandra-Fisher, K. Baines, R. West, L. Travis, S. Stewart, H. Peiris, E. Noe Dobrea, S. Hinkley, W. Golisch, D. Griep, and C. Kaminski. 1997 Atmospheric structure of Jupiter from radiometric observations of the Galileo Photopolarimeter-Radiometer (PPR) and ancillary earth-based observations. Bull Amer. Astron. Soc. 29, 1005.