The protonosphere is a layer of the Earth's atmosphere (or any planet with a similar atmosphere) where the dominant components are
atomic hydrogen and
ionic hydrogen (
protons).
It is the outer part of the
ionosphere, and extends to the
interplanetary medium
The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move. The IPM sto ...
. Hydrogen dominates in the outermost layers because it is the lightest gas, and in the
heterosphere, mixing is not strong enough to overcome differences in constituent gas densities. Charged particles are created by incoming
ionizing radiation, mostly from
solar radiation
Solar irradiance is the power per unit area ( surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
Solar irradiance is measured in watts per square metre ...
.
References
Ionosphere
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