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Titan's 2 μm surface albedo and haze optical depth in 1996–2004
Author(s) -
Gibbard S. G.,
de Pater I.,
Macintosh B. A.,
Roe H. G.,
Max C. E.,
Young E. F.,
McKay C. P.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl019803
Subject(s) - titan (rocket family) , haze , southern hemisphere , radiative transfer , atmospheric radiative transfer codes , atmosphere of titan , atmospheric sciences , observatory , geometric albedo , mars exploration program , physics , environmental science , geology , remote sensing , meteorology , astronomy , optics , stars , photometry (optics)
We observed Titan in 1996–2004 with high‐resolution 2 μm speckle and adaptive optics imaging at the W. M. Keck Observatory. By observing in a 2 μm broadband filter we obtain images that have contributions from both Titan's surface and atmosphere. We have modeled Titan's atmosphere using a plane‐parallel radiative transfer code that has been corrected to agree with 3‐D Monte Carlo predictions. We find that Titan's surface albedo ranges from ≤0.02 in the darkest equatorial region of the trailing hemisphere to ≃0.1 in the brightest areas of the leading hemisphere. Over the past quarter of a Saturnian year haze optical depth in Titan's Southern hemisphere has decreased substantially from a value of 0.48 in 1996 down to 0.18 in 2004, while the northern haze has been increasing over the past few years. As a result of these changes, in 2004 the North/South haze asymmetry at K' band has disappeared.