On the Earth, a circle of latitude or parallel is an imaginary east-west circle that connects all locations with a given latitude. The position on the circle of latitude is given by the longitude.

The polar vortex is a large area of upper-atmosphere cyclonic air circulation surrounding both poles. It is bounded by the polar jet stream and its associated cold air is usually confined to the polar ...

Last month I wrote about the Tropics of Cancer and Capricorn and their relationship to the solstices. The summer solstice for the Northern Hemisphere is June 21. Now let’s talk about how the solstices ...