Draft:Original research/Electrospheres

"Cosmic ray ionisation causes a layer of the atmosphere, the electrosphere, to remain highly conductive."

Theoretical electrospheres
Def. a highly conducting layer at which the equipotential condition is reached is called an electrosphere.

Def. a "restricted region of the magnetosphere actually occupied by plasma" is called an electrosphere.

For an aligned rotator, "Rotation induces a large pole-to-equator potential difference [...] If the work function at the surface were huge, a surface charge would appear on the sphere, in order to keep E·B = 0 in the interior. [...] charged rings [...] are released from the surface, one at a time. If [a Jupiter] choice of rotation vs field is made [...], negative particles come from the poles, positive from the equatorial zone. Each ring has the same charge. A ring released follows the magnetic field lines until it reaches a local E·B = 0 point. Positive rings from the equatorial region are therefore trapped and fill up an equatorial torus. Negative rings from the pole fly up along the field lines but do not escape if the total system charge is positive. After each new ring is released, the positions of all the others are shifted to new E·B = 0 points. Ultimately one reaches the point where there is not enough surface charge left to scrape together to make another ring of either charge [...] leaving behind a dome of negative charge and a torus of positive charge." These restricted regions are the electrosphere.

Atmospheres
"The atmosphere [of the Earth] is a good conductor to slowly varying signals at about 50 km, a level known as the electrosphere. ... The voltage between the Earth and the electrosphere in regions of fair weather is about 300,000 V. To maintain this voltage the earth has about 106 C of negative charge on its surface, an equal positive charge being distributed throughout the atmosphere. In regions of fine weather, atmospheric currents of the order of 1000 A are continuously depleting this charge. Charge is apparently replaced by the action of thunderstorms including lightning. The thunderstorm system acts as a type of battery to keep the fine weather system charged."

"The surface-electrosphere potential difference VI causes an ionic leakage current to flow vertically. Currents of order 2000 A flow in the global circuit. Applying Ohm's law with VI ∼ 300 kV, gives a global atmospheric electrical resistance RT = 230 Ω. Variations in RT arise from changes in ion concentrations: RT has its principal contribution from the planetary boundary layer, because of ion removal by aerosol. The concentric sphere system formed by the electrosphere and the planet has a finite capacitance C, with a time constant RTC of ∼10 min [Chalmers, 1967]. The continued existence of an atmospheric electric field indicates that charge generation processes are continuously active."

Fair weather fields
The "earth-ionospheric fair weather field [may arise] from the lowest order resonant excitation of the earth-ionosphere cavity by lightning".

The "same field is generated through electrostatic induction by equivalent charge dipoles from thunderclouds in the earth's atmosphere."

"An electrostatic induction model was used to derive from known worldwide thunderstorm data the magnitude of the expected earth-ionosphere fair weather potential. A value of only approximately one third of the observed potential was obtained."

Thunderstorms
A "thunderstorm supplies a negative charge to the Earth. The net positive space charge in the air between the ground and a height of ~ 10 km is nearly equal to the negative charge on the Earth's surface".

'Giant' "thunderclouds can produce transverse electric fields of tens of microvolts per meter in the equatorial plane of the midlatitude magnetosphere."

The "contribution to global thunderstorm activity by oceanic thunderstorms should be regarded as itself having a diurnal variation of some 18% in amplitude."

Concentric spherical capacitors
"The lower boundary of [the concentric spherical capacitor in theory] is the Earth's surface and the upper boundary is the electrosphere, a highly conducting layer at ~ 50 to 70 km. The electrosphere is defined as the height at which the equipotential condition is reached."

"In this model, the thunderstorm activity is the major charge generation mechanism while the fair weather conduction current is the basic consumer."

The capacitor stores 106 C.

Capacitor leakages
"Although there are many forms of charging associated with clouds, the charges must be separated faster than an 18-sec discharge rate (the capacitor leakage time-constant), otherwise the potentials will be nullified in the fair weather field."

Ionospheres
"The ionosphere, with its large electrical conductivity is not, however, a perfect conductor. Electric fields found at ionospheric heights are typically ~ 10-2 V/m or less, negligible compared to fields of up to ~ 106 V/m near thunderstorms."

"The electric currents and fields within the ionosphere and magnetosphere are driven by dynamos as well as by current generation from the lower atmosphere."

"The voltage gradient is caused by the large potential difference between the lowest layer of the ionosphere, the electrosphere, and the surface. The resulting surface potential gradient in fair weather is ∼150 V m−1 but can be as high as about 105 V m−1 in thunderstorms before a lightning discharge [Krider and Roble, 1986]."

Large-scale "ionospheric and magnetospheric convection electric fields can be seen with little attenuation in the stratosphere. ... the effects of thunderstorms extend well into the ionosphere."

An "increase in the fair weather potential gradient ... occurs at about sunrise."

An "increase in the electrosphere potential could be the source of the sunrise effect. A mechanism ... which would account for the increase in electrosphere potential [identifies] the electrosphere with a specific part of the ionosphere."

Orography
Def. "the scientific study, or a physical description of mountains" is called orography.

The "Earth's orography [has an effect] on the electric potential distribution".

The orography affects "the potential surface in the troposphere and ionosphere".

Clouds
Clouds "act as electric insulators; space charge develops on the surface of the cloud and the distribution of fair-weather currents and fields in the vicinity of the cloud are altered."

The "electrical environment around clouds is such that high space charge densities can exist."

Charge centers
The "negative charge center is located where the temperature is about -10°C, while the positive charge is less restricted to temperature and can extend over large areas."

Currents
The "total current flowing upward from thunderstorms range from ~0.1 to 7.7 A with an average of ~1.4 A per thunderstorm cell."

The total global fair weather current is estimated to be ~1000 A (~750 A over oceans and ~250 A over continents).

The total global foul weather current is estimated from "the total number of active thunderstorms [and ranges] from 1500 to 2000 ... If these numbers are multiplied by the average output current (0.5 to 1.5 A), the total current ranges from 750 to 3000 A, which agrees somewhat with the [fair weather] estimate".

Conductivity
"Galactic cosmic rays are the main source of ionization that maintains the electrical conductivity of the atmosphere from the ground to ~70 km."

"Near the ground there is additional ionization due to the release of radioactive gases from the soil, and above ~ 60 km solar ultraviolet radiation becomes important."

"The number density of both positive and negative ions stays approximately constant between 20 and 60 km altitude. The negative ion density decreases rapidly above 60 km while the electron density increases. Above ~ 65 km the electron density is greater than the negative ion density".

South Pole
"Atmospheric electric field variations recorded under fair-weather conditions on the South Polar ice-shelf in summer show the site to be globally representative and therefore of possible use in monitoring variations in the electrosphere potential."

Hypotheses

 * 1) Clouds are suspended in the capacitor due to their charges and charge fluctuations.