PDS: The Planetary Atmospheres NodePlanetary Atmospheres
Cover Page/Proposal Summary
ROSS-00 NRA 00-OSS-01
Date Due: 4/28/2000
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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: Laboratory |
| Major Equipment Proposal? No |
| Do you intend to submit an Education/Public Outreach (E/PO) proposal? No |
| Proposal Title: |
| Temperature-Dependent Cross Section Measurements of Light Hydrocarbons, In Support of Outer Planet Atmospheric Research |
| Abbreviated Proposal Title: |
| T-Dependent Cross Sections of Light Hydrocarbons |
| Principal Investigator: |
| Dr. C.Y. Wu Department of Physics & Astronomy Space Sciences Center MC-1341 University of Southern California University Park, SHS-274 Los Angeles, CA 90089-1341 Phone: 213-740-6340 Fax: 213-740-6342 E-mail: robertwu@lism.usc.edu |
| Signature | Date |
| _____________________________________ | ____________ |
| Co-Investigators and Collaborators: | |||
| Type | Name | Affiliation | |
| Sci Co-I | Professor Darrell L. Judge | USC | |
| Sci Co-I | Professor Donald E. Shemansky | USC | |
Proposal Summary:
We propose to measure the temperature (T) dependent cross sections of CH4, C2H2, C2H4, and C2H6, in the range of 140-295 K and at high resolution, in order to provide crucial data for constructing appropriate atmospheric models of the outer planets. The required data at the atmospheric T of these planets are either poorly known or have not been measured at all. Galileo Jovian Aurora data confirm that CH4 and C2H2 are present above the auroral emissions. There are clear discrepancies between models and observational data. It has been suggested that the presence of C2H4 could explain the complex features observed in the 130-140 nm region. A goal of this proposed work is to provide the data needed for a definitive answer to this important issue. The Cassini mission will provide more detailed data on the Jovian aurora. Solar and stellar occultations at Saturn by the Cassini will provide a wealth of new atmospheric data. The proposed work will supply currently unavailable data required to interpret these observations. To insure the success of atmospheric modeling and understanding, low T data are essential. The existing cross section data were reported in the 1950-1970 decades and are only available at 295 K. The first low T data of CH4 and C2H6 were reported in 1978 at 200 K while that of C2H2 was reported in 1989 at 155 K. It is important to model the atmospheres with the cross sections of these hydrocarbons measured at the appropriate T since the cross sections can vary significantly with T and lead to uncertainty in abundance and thermal structure determinations. Our existing apparatus will be employed to obtain the proposed data. Shemansky, who is on the Cassini and Galileo Teams, is also a Co-I on the present proposal. He will use the data to be obtained to rectify the deficiencies of the auroral model of Jupiter and to model the solar and stellar occultation observations of Saturn.
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:
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).
