Saturn's 5.2-μm Cold Spots: Unexpected Cloud Variability

✍ Scribed by Padmavati A. Yanamandra-Fisher; Glenn S. Orton; Brendan M. Fisher; Augustin Sanchez-Lavega

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 209 KB
• Volume: 150
• Category: Article
• ISSN: 0019-1035
• DOI: 10.1006/icar.2000.6580

✦ Synopsis

New 5.2-µm thermal images of Saturn's clouds reveal a strong axisymmetric banded structure centered at 45 • S with discrete cold spots about 30,000-50,000 km long that: (i) lower the ∼180-K brightness temperature by 8-10 K; (ii) rotate at a rate that is consistent with cloud-tracked zonal winds; and (iii) exhibit no correlation with structures seen in reflected sunlight. They are explained by variations of optical thickness of clouds just below the 1-bar level.