The coloring agents, or chromophores, that are embedded within Jupiter's vertical aerosol structure have not been identified and are poorly characterized. In this dissertation, we present two studies of chromophores in the context of the jovian atmospheric structure. In the first study, we analyzed images acquired with the Wide Field Planetary Camera 2 onboard the Hubble Space Telescope. We employed a radiative transfer code to retrieve single scattering albedo spectra, o0(lambda), for particles in Jupiter's tropospheric haze at seven wavelengths in the near-UV and visible regimes. All o0 curves were absorbing in the blue, and o0(lambda) increased monotonically to approximately unity as wavelength increased. We found accurate fits to all o0(lambda) curves using an empirically derived functional form: o 0(lambda) = 1 -- A exp(--Blambda ). The best-fit parameters for the mean o 0(lambda) curve were A = 25.4 and B = 0.0149 for lambda in units of nm. We performed a principal component analysis (PCA) on our o0(lambda) results and found that one or two chromophores were sufficient to produce the variations in o0(lambda). A PCA of reflectance spectra, I/F(lambda) for the same jovian locations resulted in principal components (PCs) with roughly the same variances as the o0(lambda) PCA, but they did not result in a one-to-one mapping of PC amplitudes between the o 0(lambda) PCA and I/F(lambda) PCA. We suggest that statistical analyses performed on I/F(lambda) have limited applicability to the characterization of chromophores in the jovian atmosphere due to the sensitivity of I/F(lambda) to horizontal variations in the vertical aerosol distribution. In the second study, we collected and analyzed images of Jupiter from 470--900 nm in 2-nm increments. We acquired our data with the New Mexico State University Acousto-optic Imaging Camera using the Astrophysical Research Consortium 3.5-meter telescope at Apache Point Observatory. We retrieved o0(lambda) for four jovian locations and confirmed the applicability of the functional form for o0(lambda). We performed PCA, non-negative matrix factorization, and vector quantization on our I/F(lambda) image cubes. These results are also consistent with one, possibly two, chromophores in the jovian atmosphere.
- Pub Date:
- Physics, Astronomy and Astrophysics;Physics, Optics