A massive storm on Saturn

Since the Cassini spacecraft entered orbit around Saturn, storms in the atmosphere of this planet have been observed and photographed. The duration of the observed storms was usually tens of days.

Since the entry of the Cassini spacecraft into orbit around Saturn, storms in the atmosphere of this planet have been observed and photographed. The duration of the observed storms was usually tens of days. One storm was observed by the Hubble telescope 22 years ago and lasted 55 days. A telescopic observation from Earth from 1903 identified a storm that lasted 150 days (1). Since a day on Saturn lasts approximately 11 earthly hours, the duration of this storm is 13.6 times longer than its day. What is it similar to? If we take the same ratio, such a storm would have lasted 326.4 days (326.4 = 13.6X 24). In the national data, close to a year. A year on Saturn is equal to 29.5 Earth years, so the duration of this storm on Saturn is 0.014 one Saturn year. Even on this scale you can feel the power of the storm. According to this ratio, the duration of such a storm on Earth is 5.1 days. A storm on a larger scale began on 5.12.2010 and in the report given on 22.11.2011 the storm was active even after 200 days of observation. (1) . What does this mean in terms of the destruction and devastation that such a storm leaves on Earth? It is best left to the imagination of the reader.

A radio and plasma wave observation from the Cassini showed the electrical activity of the storm. It turned out that this storm is a convective thunderstorm. The active convection ended at the end of June 2011. The swirling clouds that formed continued into July 2011 as well.
This observation was made as part of a collaboration between amateur astronomers, the operators of the Cassini spacecraft and the operators of the European telescope - VLT (Very Large Telescope) in Chile (2). The geographic location where the storm started was at N ° 35. Based on all the observations of the storms on Saturn, it became clear that there is a fundamental difference between them and storms on Earth and Jupiter. In these two planets the storms are frequent. On Saturn the weather can be quiet for years and then it erupts violently and with great force. At its peak, this storm creates 10 lightning bolts per second. Although the Cassini is equipped with high-resolution instruments, it was difficult to isolate each of them individually when the storm was at its peak (3).

The Cassini photographs do not cover one year of Saturn. That's why we also used photographs taken by the Voyager spacecraft that passed by and telescopic photographs taken from Earth over decades. From this set of observations it became clear that the atmosphere is generally quiet. Once in Saturn's year when the spring season begins in the Northern Hemisphere, something of unknown nature stirs deep in the atmosphere below the clouds and causes an atmospheric disturbance on a global scale. It is this disturbance that creates vortices and it is this eddy that created this massive vortex and the complex eruptions of cloud material that were scattered around the planet. Monitoring With the help of modern equipment, including infrared, it is possible to look deep into the atmosphere and measure significant changes in temperature and winds associated with this event.

This storm is similar to thunderstorms that send plumes of convection currents upward and reach the upper atmosphere. It also comes into contact with winds surrounding Saturn in the east and west direction and causes sharp temperature changes in the upper atmosphere. This storm transports energy and matter over great distances, creating winding jet streams and large eddies. Some of the formations that were created were named stratospheric beacons. The major temperature changes occur at an altitude of 250-300 km above the tops of the clouds. Usually the temperature in the stratosphere is -130°C. In this season of the year the temperature in the lighthouses rises by 20 - 15 C. In these beacons you can distinguish infrared (2).

In a photo taken on 25.2.2011, about 3 weeks after the start of the storm (4), you can see that the clouds in this storm formed a tail surrounding the planet. Some of the clouds moved south and were caught in currents moving east. The surface area of ​​this storm is 500 times larger than the largest storms observed in the Southern Hemisphere by Hexini.

Large storms observed in the past in the Northern Hemisphere in time frames of Saturn years were given the name Great White Spots. They usually appeared towards the end of summer in the Northern Hemisphere. If indeed this massive storm is a great white spot, it appeared earlier than expected. The length of the storm is 20,000 km, similar to the length of the great spots that surround Saturn. This storm is also a source of strong radio noise that comes from lightning deep in the atmosphere. Lightning is created in water clouds that generate electric currents. It is not clear why Saturn stores energy for decades and releases it all at once.

The intensity of the development of this fire can be learned by comparing two photographs from another cave in the photograph taken on 5.12.2010. The dimensions of the storm in the north-south direction were 1300 km and 2500 km in the east-west direction. In a photo taken 3 weeks later on 24.12.2010/10,000/17,000. The length of the storm in the southeast direction is 100,000 km and in the east-west direction 5 km. Photographs taken at the time showed that the length of the tail of the storm is 4 km (8). In another photo, the area of ​​the storm is 100 billion square kilometers, 100 times the area of ​​the continents on Earth. The highest clouds in this photograph are located about 6 km above the clouds where there are no disturbances and the atmospheric pressure in this place is XNUMX millibars. The base of the clouds where the lightning is formed is in a layer of water clouds. It is estimated that storm clouds are made of water ice covered in ammonia crystals (XNUMX).

There are researchers who believe that this storm is a collection of super storms created by an increase in heat and moisture and ammonia from water clouds found in low layers of the atmosphere, where the atmospheric pressure is high. When this mixture rises to the layer of the cold atmosphere - the tropopause (a layer below the stratosphere), the ammonia clouds begin to expand horizontally into the tail of the storm by jets of winds moving eastward (7).
Sources

1. "Cassini chronicles the life and times of giants on Saturn" 22.11.2011
2. http://spacedaily.com/reports/Cassini_Chronicles_The_Life_And_Times_Of_ Giant_On_Saturn_999.html

2. "Looking deep into a huge storm on Saturn" 20.5.2011
http://spacedaily.com/reports/Looking_Deep_Into_A_Huge_Storm_On_ Saturn_999.html

3. "Cassini spacecraft captures images and sounds of big Saturn storm" 7.7.2011
http://spacedaily.com/reports/ Cassini_ Spacecraft_ Captures_ Images_And_Sounds_ Of_ Big_Saturn_ Storm_999.html

4. PIA12826: Catching its tail
http://photojournal.jpl.nasa.gov/ PIA12826/

5. PIA12824: Spotting Saturn's northern storm
http://photojournal.jpl.nasa.gov/ PIA12824

6. PIA12825: A day in the life
http://photojournal.jpl.nasa.gov/ PIA12825

7. "Tempest-from hell-seen on Saturn" 6.7.2011
http://spacedaily.com/reports/ Tempest_ From_ Hell_ Seen_ On_ Saturn_999.html