Cover Page/Proposal Summary

ROSS-00    NRA 00-OSS-01

Date Due: 4/28/2000

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: Atmosphere Structures and Particles

Major Equipment Proposal? No

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

Proposal Title:

Research in Planetary Atmospheres-Jupiter and Titan(Continuation of Grant NAG5-4589)

Abbreviated Proposal Title:

Jupiter and Titan Atmospheric Composition & Str.

Principal Investigator:

Dr. Sushil K. Atreya Dept. Atmos. Ocean. & Space Sciences University of Michigan Space Research Bldg. Ann Arbor, MI 48109-2143 Phone: 734-763-6234   Fax: 734-764-5137   E-mail: atreya@umich.edu

Signature	Date
_____________________________________	____________

Co-Investigators and Collaborators:
Type	Name	Affiliation	E-mail
Sci Collab	Dr. Therese Encrenaz	Obs. Paris-Meudon	therese.encrenaz@obspm.fr
Sci Collab	Dr. Paul R. Mahaffy	GSFC	paul.r.mahaffy@gsfc.nasa.gov
Sci Collab	Dr. Hasso B. Niemann	GSFC	hasso.b.niemann@gsfc.nasa.gov
Sci Collab	Dr. Tobias C. Owen	Univ. Hawaii	owen@ifa.hawaii.edu

Proposal Summary:

Continuation of grant NAG5-4589 is proposed. Under the current grant, observations from Galileo, HST and ISO were analyzed and interpreted. We determined that the condensible volatiles (H2O, H2S, NH3) were unexpectedly depleted to depths well below their equilibrium condensa- tion levels in Jupiter’s deep troposphere. We have suggested that this behavior, as well as the lack of substantial clouds, is a direct consequence of local meteorology in the 5 micron hotspot, the entry site of the Galileo probe. From the supersolar ratios (to H) of the heavy elements (C,N,S,Ar,Kr,Xe) we measured, it was concluded that the planetesimals that formed the core of Jupiter must have been very cold (<30 K). The protosolar D/H value was fixed from an in situ Jovian D/H measurement. We found the global values of eddy mixing in the atmospheres of Uranus and Saturn to be comparable to the equatorial values measured by Voyager. Eddy mixing coefficient in the upper tropospheres and lower stratospheres of Jupiter and Saturn were also derived. We propose to continue the analysis of the Galileo probe mass spectrometer (GPMS) data, and make further progress on a model of the chemical evolution of Titan’s atmosphere. Our goal is to characterize the composition and structure of these bodies as fully as possible. In particular, we will determine the distributions of C2 - and the heavier hydrocarbons in the 1-20 bar range, the molecular nitrogen abundance, and the nitrogen isotopic ratio in Jupiter’s atmosphere, by analyzing the GPMS data. We will also refine our analysis of the Jovian water vapor data. We will develop the model of chemistry of Titan’s atmosphere further. All observational results will be interpreted with coupled condensation-chemistry models to be developed or updated simultaneously. Supporting data will be obtained from other missions, in particular ISO.

Certification of Compliance with Applicable Executive Orders and U.S. Code By submitting the proposal identified in this Cover Sheet/Proposal Summary in response to this NRA or AO, the Authorizing Official of the proposing institution (or the individual proposer if there is no proposing institution) as identified below: certifies that the statements made in this proposal are true and complete to the best of his/her knowledge; agrees to accept the obligations to comply with NASA award terms and conditions if an award is made as a result of this proposal; and confirms compliance with all provisions, rules, and stipulations set forth in the three Certifications contained in this NRA [namely, (i) Certification Regarding Debarment, Suspension, and Other Responsibility Matters Primary Cover Transactions, (ii) Certification Regarding Lobbying, and (iii) Certification of Compliance with the NASA Regulations Pursuant to Nondiscrimination in Federally Assisted Programs]. Willful provision of false information in this proposal and/or its supporting documents, or in reports required under an ensuing award, is a criminal offense (U.S. Code, Title 18, Section 1001).