Cassini/CIRS Observations of Temperatures in Saturn's Northern Storm Region

Details Cassini/CIRS Observations of Temperatures in Saturn's Northern Storm Region Cassini/CIRS Observations of Temperatures in Saturn's Northern Storm Region

Dec 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufm.p13c1680a&link_type=abstract

American Geophysical Union, Fall Meeting 2011, abstract #P13C-1680

Physics

[5704] Planetary Sciences: Fluid Planets / Atmospheres, [5739] Planetary Sciences: Fluid Planets / Meteorology

Scientific paper

In early December 2010, a large convective storm appeared in Saturn's northern hemisphere, centered near 40°N planetographic at the center of a westward jet (Sanchez-Lavega et al., 2011; Fisher et al. 2011). Storms of the observed magnitude, referred to as Great White Spots (GWS), are rare on Saturn, historically occurring once per Saturn year (30 Earth years), at equatorial or mid-northern latitudes during northern summer; the current storm is unusual in occurring during northern spring, roughly one season earlier than previous GWS outbursts. Thermal infrared observations, both groundbased and from the Cassini Composite Infrared Spectrometer (CIRS) orbiting Saturn, taken six weeks after the appearance of the storm, revealed significant changes to the thermal structure of Saturn's northern hemisphere (Fletcher et al., 2011). Cold temperatures were measured at the location of the disturbance in both the upper troposphere and stratosphere, and, surprisingly, hot spots to the east and west of the disturbance longitude with temperature contrasts of 16K, much larger than usual zonal temperature contrasts on Saturn. CIRS has continued to observe the latitude of the storm at one to two month intervals. These observations typically cover an approximately 10° wide latitude strip over one or two rotations of Saturn at a spatial resolution of 2° of arc in the CIRS mid-IR focal planes (600-1400 cm-1, 7-16μm). From these observations, we can retrieve temperatures in the upper troposphere between 50 and 200 mbar, and in the middle stratosphere between ~0.2 and 10 mbar. These observations show that temperatures in the stratospheric hot spots continued to increase through May 2011, when temperatures reached a peak of over 220 K, following the merger of two hot spots into one, with zonal temperature contrasts of 70 K. By mid-July, the maximum temperature in the hot spot had decreased to just under 200K. Furthermore, in May and July, the peak temperatures were at a pressure roughly two scale heights larger (lower in altitude) than in earlier observations - 2 mbar compared to 0.4 mbar. In the upper troposphere, temperature perturbations associated with the storm are around 5 to 10 K, larger than seen on Saturn prior to the storm, but much smaller than the temperature variations seen in the stratosphere.

Affiliated with

Also associated with

No associations

Rating

Cassini/CIRS Observations of Temperatures in Saturn's Northern Storm Region 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 Cassini/CIRS Observations of Temperatures in Saturn's Northern Storm Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cassini/CIRS Observations of Temperatures in Saturn's Northern Storm Region will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-868252