PHYS6074: Ionosphere 7

What does coherent scatter radar (like SuperDARN) measure?

• Line-of-sight ion velocity

• Height of F-region peak

• Neutral temperature

• Ion-neutral collision frequency

What does a riometer measure?

• D-region absorption

• F-region peak altitude

• F-region peak electron density

• Line-of-sight ion velocity

Which current is carried by precipitating energetic auroral electrons?

• Upward field-aligned current

• Downward field-aligned current

• Hall current

• Pedersen current

Which conductivity is important for Joule heating?

• Pedersen conductivity

• Parallel conductivity

• Thermal conductivity

• Conductivity is not important!

If ion and neutral velocities have the same magnitude, under which conditions will Joule heating be a maximum?

• Ion and neutral velocities equal

• Ion and neutral velocities perpendicular to each other

• Ion and neutral velocities oppositely directed

Which temperature is usually greatest in the upper ionosphere?

• Electron temperature

• Ion temperature

• Neutral temperature

• They are all equal