Takafumi Temma
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| Research Assistant |
| Entered: | 1999 |
| Office: | 101 Astronomy |
| Phone: | (575)646-4438 |
| Fax: | (575)646-1602 |
| |
| E-mail: | temma |
| (append "@nmsu.edu") |
| |
|
|
| M.S. | Kyoto University, | 1998 |
| B.S. | Kyoto University, | 1995 |
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Research
I am working with Dr. Nancy Chanover to study the vertical cloud structure
in Saturn's atmosphere. We have used the the Air Force Research
Laboratory's 3.67-meter Advanced Electro-Optical System telescope in Hawaii
to take a series of narrow-band images of Saturn over the wavelength range
500 to 950 nanometers. The high wavelength resolution and wide spectral
coverage of the Acousto-optic Imaging Spectrometer (AImS) enabled us to
sample different altitudes of the Saturnian equatorial region with higher
vertical resolution than conventional narrow-band filter observations, and to
derive the wavelength dependence of aerosol optical properties.
We fit the center-limb profiles in the Saturnian equatorial region
with theoretical profiles generated from radiative transfer
computations. We simultaneously fit five different profiles around the 890
nanometer methane band and four profiles around the 727 nanometer methane
band to determine the vertical cloud structure and the aerosol property
variation as a function of wavelength. Adopting four different cloud
structure models with three different aerosol scattering phase functions, we
varied at most nine free parameters and tried a total of 5800 initial
conditions for optimization to seek the best solution in the vast
multi-dimensional parameter space.
In the Saturnian equatorial region, we draw the following main conclusions:
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The tropospheric cloud extends up to the stratosphere (above 100 mb).
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The wavelength dependence of the aerosol opacity suggests a lower limit of
the average aerosol size of roughly 0.7 - 0.8 microns for the upper
tropospheric cloud.
Publications
Optical Spectro-photometry of Saturn with a Passband-tunable Imaging System
Temma, T., N. J. Chanover, D. A. Glenar, J. J. Hillman, D. M. Kuehn, & A.
A. Simon-Miller, 2004, Icarus, in press
Postdoctoral Work
I successfully defended my Ph.D. thesis on Vertical Structure Modeling of
Saturn with High-Spectral Resolution Imaging, on December 9, 2004. I then
accepted a National Academies Postdoctoral Fellowship at the Jet Propoulsion
Laboratory, to work on Saturnian Cloud Structure Study & Trace Element
Mapping with the Cassini VIMS Instrument.
