Saturn's Dynamic Atmosphere at Depth: Physical Characteristics and Zonal Winds Derived from Clouds Near the 2-bar Level and Their Dynamical Implications from Cassini-Huygens/VIMS

Details Saturn's Dynamic Atmosphere at Depth: Physical Characteristics and Zonal Winds Derived from Clouds Near the 2-bar Level and Their Dynamical Implications from Cassini-Huygens/VIMS Saturn's Dynamic Atmosphere at Depth: Physical Characteristics and Zonal Winds Derived from Clouds Near the 2-bar Level and Their Dynamical Implications from Cassini-Huygens/VIMS

Sep 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008dps....40.4113m&link_type=abstract

American Astronomical Society, DPS meeting #40, #41.13; Bulletin of the American Astronomical Society, Vol. 40, p.472

Astronomy and Astrophysics

Astronomy

Scientific paper

A wide variety of cloud structures - comprised, putatively, of ammonia and ammonia hydrosulfide , but perhaps with an admixture of water - has been characterized by Cassini/VIMS, including dozens of axisymmetric zonal features, planetary waves, classic vortex structures at both the north and south poles, and a hexagonal slow-speed wave feature centered on the north pole. At depth, the axisymmetric zonal features average just 1.7 degrees in latitudinal width, less than half of that at the 0.05- and 0.5-bar levels observed in reflected sunlight, suggesting that either (1) the patterns of ascending/descending motion have smaller latitudinal length scales at > 1.3 bar than at shallower levels, and/or (2) horizontal mixing is better able to "smooth out" the cloud structure at shallow levels than at depth. Numerous long-lived (> 1.5-years) discrete cloud structures have been observed in the northern hemisphere, including annular ("donut") clouds near 49 and 57 degrees north latitude (planetocentric) and a "string of pearls” of some two-dozen similarly sized ( 1500 km diameter) cloud-clearings nearly uniformly spaced across 100 degrees of longitude near 33.5 degrees latitude. The "string of pearls” and the mid-latitude annular cloud exhibit the fastest retrograde speeds on Saturn (in the Voyager rotational frame). In the south, the fastest retrograde jet correlates with the only thunderstorm-associated clouds observed on Saturn. VIMS daytime spectra indicate that two kinds of clouds predominate there: spectrally bright and spectrally dark. The bright clouds are the first spectrally-identified ammonia clouds on Saturn, presumably formed by ammonia-laden air propelled upward by thunderstorm-related convection originating > 75 km below. Thus both vertically-extensive (thunderstorms) and long-lived, coherent cloud features ("pearls” and "donuts") correlate well with retrograde motions, perhaps indicating unusually low vertical shears there which preserve coherency and allow convective flows to rise relatively unimpeded over large vertical distances.

Affiliated with

Also associated with

No associations

Rating

Saturn's Dynamic Atmosphere at Depth: Physical Characteristics and Zonal Winds Derived from Clouds Near the 2-bar Level and Their Dynamical Implications from Cassini-Huygens/VIMS does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Saturn's Dynamic Atmosphere at Depth: Physical Characteristics and Zonal Winds Derived from Clouds Near the 2-bar Level and Their Dynamical Implications from Cassini-Huygens/VIMS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Saturn's Dynamic Atmosphere at Depth: Physical Characteristics and Zonal Winds Derived from Clouds Near the 2-bar Level and Their Dynamical Implications from Cassini-Huygens/VIMS will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1438623