Conceptual Model of the Earth’s Global Electric Field

Maxwell’s Equations

Conceptual Model of the Earth’s Global Electric Field

Earth’s Magnetic Field

Earth’s Magnetic Field

ar

Ra

r

RB E

rE

cos3.0

sin6.0

3

3

3

3

ar

Ra

r

RB E

rE

cos3.0

sin6.0

3

3

3

3

The Ionosphere

The Ionosphere

• There are enough ions and electrons to make the atmosphere a reasonably good conductor

• Charged particles are created when solar radiation at wavelengths shorter than 102.7 nm is absorbed (photoionization)

The Ionosphere: The D-layer

• Most of the shorter uv rays have been absorbed in E and F

• Longer wavelengths (l<111.8nm), x-rays and solar cosmic rays are primarily responsible

• Disappears at night

The Ionosphere: The E-layer

• A Chapman layer– The production of ions in a given region is

proportional to flux of radiation and to the number of molecules in that region

– Two opposing tendencies• Flux diminishes• Number density increases

• Ionization of O2 and N2

• Transition occurs from well mixed

The Ionosphere: The F-layer

• F1: Chapman layer– Ionization of O (i.e. atomic oxygen) at even shorter

wavelengths (l<91.1nm)– O+ reacts with O2 and N2 to create ionized

molecules• F2: modified Chapman Layer– Ionization of O (i.e. atomic oxygen) at still shorter

wavelengths (l<80nm)– Also some ionization of N2

The losses• We are “creating” all of these charges, where

does it go?• D-region: electron capture by positively charged

ions• E-region: dissociative recombination of a

molecule that reacts with an electron• F-regions: dissociative recombination of a

molecule that reacts with an electron– The difference in F1 and F2 is the reaction rate differs

Ionosphere electron desnisty