Invariant latitude

Invariant latitude is a parameter that describes where a particular magnetic field line touches the surface of the Earth. It is given by

$Lambda\; =\; arccosleft(sqrt\{1/L\}\; ight)$

or

$L\; =\; 1/cos^2left(Lambda\; ight)$

where $Lambda$ is the invariant latitude and $L$ is the L-value describing the magnetic field line in question.

ee also

* Earth's magnetic field
* L-shell
* Geomagnetic latitude

References

* Margaret Kivelson and Christopher Russell (1995), "Introduction to Space Physics, New York, NY: Cambridge University Press, pp. 166-167