SEASONAL CHANGES IN TITAN'S SURFACE TEMPERATURES
- Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
- Department of Physics, Catholic University of America, Washington, DC 20064 (United States)
- LESIA, Observatoire de Paris-Meudon, 92195 Meudon Cedex (France)
- Institut fuer Geophysik und Meteorologie, Universitaet zu Koeln, Albertus-Magnus-Platz, 50923 Koeln (Germany)
Seasonal changes in Titan's surface brightness temperatures have been observed by Cassini in the thermal infrared. The Composite Infrared Spectrometer measured surface radiances at 19 {mu}m in two time periods: one in late northern winter (LNW; L{sub s} = 335 deg.) and another centered on northern spring equinox (NSE; L{sub s} = 0 deg.). In both periods we constructed pole-to-pole maps of zonally averaged brightness temperatures corrected for effects of the atmosphere. Between LNW and NSE a shift occurred in the temperature distribution, characterized by a warming of {approx}0.5 K in the north and a cooling by about the same amount in the south. At equinox the polar surface temperatures were both near 91 K and the equator was at 93.4 K. We measured a seasonal lag of {Delta}L{sub S} {approx} 9{sup 0} in the meridional surface temperature distribution, consistent with the post-equinox results of Voyager 1 as well as with predictions from general circulation modeling. A slightly elevated temperature is observed at 65{sup 0} S in the relatively cloud-free zone between the mid-latitude and southern cloud regions.
- OSTI ID:
- 21562485
- Journal Information:
- Astrophysical Journal Letters, Vol. 737, Issue 1; Other Information: DOI: 10.1088/2041-8205/737/1/L15; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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