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Titan's latitudinal temperature distribution and seasonal cycle
Author(s) -
Stevenson David J.,
Potter Brian E.
Publication year - 1986
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/gl013i002p00093
Subject(s) - equator , titan (rocket family) , latitude , polar , atmospheric sciences , troposphere , geology , physics , astrobiology , astronomy , geodesy
Voyager IRIS brightness temperature measurements of Titan at a wavelength of 530 cm −1 are crudely indicative of ground or lower tropospheric temperatures and indicate 93 K for the equator and 91 K for both northern and southern high latitudes. The symmetry between north and south is unexpected for the time of Voyager encounter (Northern Titan spring). We show that this near‐symmetry can arise naturally in a model where the poles are "pinned" year‐round at the dew point of CH 4 ‐N 2 lakes or, more probably, a CH 4 ‐N 2 rich surface layer on a deep ethane‐rich ocean. For a polar temperature of 91 K, the model implies that the atmosphere contains somewhat less than 8% mole fraction of CH 4 .