Uranus is the seventh planet distant from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. The Uranian system has a unique configuration among those of other planets of the solar system because its axis of rotation is tilted sideways, nearly into the plane of its solar orbit. Its north and south geo poles, therefore, lie where most other planets have their equators. Uranus axis of rotation is tilted by 97.77° to the perpendicular axis of its solar orbit. When it comes to Uranus, scientists are faced with many unanswered questions including:
- Why when the polar regions of Uranus receive a greater energy input from the Sun than its equatorial regions, Uranus is hotter at its equator than at its geo poles?
- Why the magnetic field at the northern region (the upper half of the planet above the solar plane) is stronger than the magnetic field at the southern region (the lower half of the planet below the solar plane) ?
- Why does Uranus spin in a clockwise direction about its axis, when Earth, currently, spins in an anti clockwise direction about its axis?
- Why does the wind average speed reach 560 miles/ hour (900km/ hour) on Uranus while on Earth an inconceivable top wind speed of Tornado stands at 319 to 379 mile/ hour (510 to 600 km/ hour)?
The standard model of Uranus’s structure consists of four features:
- a rocky (silicate/iron–nickel) core in the centre, which is relatively small, with a mass of 0.55 Earth mass, of around 9 gm/cm3 and a radius less than 20% of Uranus’s with a pressure at the centre of 8 million bars (800 GPa) and a temperature of about 5000° Kelvin (4726° Celsius) ,
- an icy mantle in the middle, which is not in fact composed of ice in the conventional sense, but of a hot and dense fluid consisting of water, ammonia and other volatiles. That fluid, which has a high electrical conductivity, is sometimes called a water–ammonia ocean , and
- an outer gaseous hydrogen/helium envelope where temperature drops below freezing point to an average of 68° Kelvin (or -205° Celsius).
- a magnetic dipole axis that does not pass through the centre of the planet. The south magnetic pole in the northern region makes an angle of 44° with the axis of rotation while the north magnetic pole in the southern region makes an angle of 76°. On Earth there is a similar situation, where the south magnetic pole in the Arctic region makes an angle of 10° with the axis of rotation, while the north magnetic pole in Antarctica makes an angle of 23°.
I recalled, what if I apply on Uranus the same logic that I deployed earlier to find the true driver behind i) the variation of climates on the face of Earth, ii) the configuration of the magnetic field that has constantly wandering magnetic poles, and iii) the variation at the spinning speed of Earth about its axis; to be able to attend to the first 3 questions above for Uranus.
As explained on the Earth Temperature page of this site, the Temperature Belts, or regions of homogeneous climates are greatly influenced by the location of the magnetic pole, more than by the orthographic projection of Sun radiation and/ or geo distance from the Sun. This is highly attributed to the radiation, which is generated from the collisions of charged particles that continuously arrive from the Sun with one another; as they spiral along the magnetic field force lines that engulf the planet. On Earth, I found out that the tilting or relocation of the 2 magnetic poles leads to tilting of the Temperature Belts; resulting in Climate Exchange, where arid land became lush green and vice versa. Geological records carried evidence of it. The fact that the magnetic field is at its weakest intensity at the midpoint between two magnetic poles due to planet curvature, and at its strongest intensity at the magnetic poles, where the magnetic force lines flux out/ flux in, leads to making the charged particles travel at variable speed along the magnetic field force lines that connect the 2 magnetic poles. In other words, the charged particles travel speed between the 2 magnetic poles is inversely proportionate to the strength of the magnetic field. The model that I applied for Earth proved that the radiation, which is generated from such collisions varies in strength. It stands at a maximum at the mid distance between the 2 magnetic poles, where charged particles spiral at their highest speed due to low magnetic intensity, and at minimum above the 2 magnetic poles, where charged particles are travelling at their lowest speed due the high magnetic intensity. I found out through modelling that on Earth, the energy generated by such collisions of charged particles of one another, is twice the energy that reaches Earth directly from the Sun. Scientists called the region where the magnetic field force lines lie above the surface of Earth: Thermosphere. I shall use the same term to name the region where Uranus magnetic field force lines lie above its surface. The charged particles collision’s thermal energy is at its maximum thrust in the Thermosphere region above the midpoint between the 2 magnetic poles (the magnetic equator), where the magnetic field stands at the lowest intensity, and at its minimum thrust at the Thermosphere region above the magnetic poles, where the magnetic field stands at its highest intensity. This makes the region of the magnetic equator to earn the highest temperature on the surface of the planet, and the region of the magnetic poles to be the lowest temperature on the surface of the planet and drags low the temperature at the neighboring geo poles. Whether facing the Sun at close projection and proximity or not, the geo poles will always have lower temperature than the planet’s equator. This answers question 1 above.
As explained earlier on the Earth Magnets page of this site, by applying the Coriolis Effect it is evident that there are 2 types of magnetic field forces that are emitting from the core of Earth. A permanent magnetic field with clear south and north polarity poles, and an induced magnetic field force with south polarity at both geos, and stands behind the Plasmoid phenomena that started to appear in Antarctica since 10,000 years. The source of induced magnetism is the spiraling electrons flowing at the Outer Core. The source of the permanent magnetism can be nothing but the Inner Core. It appears that Uranus core is composed of similar material as the Earth’s Inner Core, and that Uranus inner mantle, which is in liquid state performs a similar function to Earth Outer Core that is in liquid state as well. The fact that Uranus mantle has a high electrical conductivity, confirms that Uranus core is as radioactive as Earth’s Inner Core if not higher, otherwise where would the high flow of electrons come from. The fact that Uranus has a greater mass, but does spin faster about its axis than Earth leads to one of 3 possibilities, following Earth Spin Speed model that I explained earlier on this site, in which I demonstrated that the Lorentz Force is the driver for any planet to spin about its axis. The 3 possibilities are i) Uranus has a much powerful magnetic field, ii) and/ or, it has a much stronger electronic current that is generated from its core, iii) and/ or, the angle between these 2 electromagnetic forces is a right angle at 90°. Since Uranus average magnetic field at the surface is only 0.23 gauss (23 µT), which is weaker than Earth’s; having an average of 0.5 gauss (50 µT) , and since the angle between the magnetic dipole and the axis of rotation is less than 90° as per the diagram above, then there is no escape but to have a much higher rate of electrons currents flowing out of Uranus core to fuel the Lorenz Force and bring the planet to spin about its axis at a faster speed than Earth even when its mass is 14.5 times that of Earth.
Having established the fact that electrons are flowing out of Uranus core, into the lower layer of its mantle that exists in liquid sate, brings the Coriolis Effect into force and lead to a similar generation of “induced” magnetic field force lines that appear of south polarity when observed from Uranus surface at both its northern and southern hemispheres. The addition of induced south polarity magnetic field next to a permanent south polarity magnetic pole in the northern hemisphere of Uranus leads to an increased reading of south polarity magnetic intensity in the northern region of Uranus. Vice versa, the addition of induced south polarity magnetic field next to a permanent north polarity magnetic pole in the southern hemisphere of Uranus leads to capturing the permanent magnetic field force lines even before emergence at surface and brings the decreased reading of the north polarity magnetic intensity in the southern region of Uranus and answers question 2 above.
The intensity of the induced magnetic field force lines is proportionate to the speed of the flowing electrons. The speed of the flowing electrons is proportionate to the distance from the centre of the planet following the formula of v= w.r ; where w is the constant spin speed and r is the distance of a flowing electron from the centre of the planet. A fast electronic current brings a strong induced magnetic field that reaches its peak at the tangent shell that separate the lower liquid mantle from the upper frozen mantle. Unlike Earth where the permanent magnetic field is stronger than the induced magnetic field, Uranus strong induced magnetic field plays a key role to driving the planet to spin and a another role to causing huge variations in surface temperature to bring about variations in pressure leading to winds at such high speed.
At the higher layer of Uranus mantle where the state becomes solid due to extreme low temperature at the surface, the interaction between i) flowing electrons that always follow a perpendicular, spiraling trajectory to the axis of rotation, according to Coriolis Effect for particles moving on a rotating disk or in rotating sphere, ii) a permanent magnetic field force lines that flow out from a permanent north magnet, and flow in at a permanent south magnet, and iii) an induced magnetic field force lines of south polarity that are parallel to the axis of rotation (perpendicular to the electrons flow trajectory), leads to the generation of a Lorenz Forces at the tangent shell between the 2 layers of the mantle. The interaction of such permanent and induced magnetic fields force with the electrons current, as shown in the diagram above produce a force that is called Lorenz Force (also known as Left Hand Rule of electromagnetism), which drives the planet to spin and explains why Uranus is propelled to spin in a clockwise and not anti-clockwise direction like Earth. This answers question 3 above.
Magnetic forces at Arc 120°, Arc 106° and the 2 magnetic poles work on the same direction and present in aggregate a higher magnetic field magnitude than that combined of at Arc 60° and Arc 74°, whose magnetic forces work in the opposite direction. The net magnetic field force brought into the Left Hand Rule confirms the spin in Clockwise direction. But, it also bring about an epic struggle of 2 opposing groups of Lorenz Forces at the crossing boundaries of Arc 60° and Arc 74° and the shell separating the inner from outer mantle. The collision of the opposite Lorenz Forces result in quakes and rifts in the outer frozen mantle. The escape of liquid at high temperature from inner liquid mantle to surface through outer frozen mantle aperture leads to rising temperature on the surface. The variance in atmospheric temperature causes a variance in atmospheric pressure. Wind is caused by differences in the atmospheric pressure. When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area, resulting in winds of various speeds. The large variance of temperature leads to large variance of pressure, which in turn leads to generation of high speed winds. This answers question 4 above.
By investigating the location of the magnetic poles at all giant gas planets of the solar system , it appears that the same spin model that applies on Uranus does apply on all other 3 giant gas planets;
- On Uranus, the magnetic pole of north polarity is located in the southern region of the planet. The planet spin is clockwise.
- On Jupiter, the magnetic pole of north polarity is located in the northern region of the planet. The planet spin is anti-clockwise
- On Saturn, the magnetic pole of north polarity is located in the northern region of the planet. The planet spin is anti-clockwise
- On Neptune, the magnetic pole of north polarity is located in the northern region of the planet. The planet spin is anti-clockwise
 Podolak, M.; Weizman, A.; Marley, M. (December 1995). “Comparative models of Uranus and Neptune”. Planetary and Space Science. 43 (12): 1517–1522
 Faure, Gunter; Mensing, Teresa (2007). “Uranus: What Happened Here?”. In Faure, Gunter; Mensing, Teresa M. Introduction to Planetary Science. Introduction to Planetary Science. Springer Netherlands. p. 369
 Planetary magnetic fields: Observations and models, G. Schubert ⇑, K.M. Soderlund, Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095, USA.