Category Archives: Phenomena
This question was considered by astronomer Johannes Kepler about 400 years ago.
Kepler published an article on the topic in 1611. He hypothesized that the crystals were made of subunits that combined to form the symmetrical shapes of ice crystals. Continue reading
Both La Niña and El Niño refer to big changes in the sea-surface temperature across much of the eastern tropical Pacific Ocean.
The water temperatures off the west coast of South America are typically 60 to 70 degrees. During a La Niña, these waters get as much as 7 degrees colder. These La Niña conditions recur every few years and last nine to 12 months, though some events have lingered for as many as two years. This cooling results from a strengthening of the winds over the tropical Pacific and its interaction with the underlying ocean waters. Continue reading
Ozone occurs about 18 miles above the Earth’s surface.
Ozone is both caused by and provides protection from damaging ultraviolet energy emitted by the sun. The development of an atmospheric “ozone layer” allowed life to move out of the oceans and onto land.
The amount of ozone in the atmosphere is routinely measured from satellites. Typically, the Antarctic ozone hole has its largest area in early September and lowest values in late September to early October. This year it was measured to be one of the largest and deepest in recent years, covering just over 9 million square miles. Continue reading
There are two types of waterspouts: fair weather waterspouts and tornadic waterspouts.
A fair weather waterspout is a whirlwind that forms beneath a cumulus cloud and over water. It’s generally not associated with thunderstorms.
A fair weather waterspout develops on the surface of the water and moves upward. Before you see the waterspout, you may see a funnel cloud hanging from the bottom of the cumulus cloud. A waterspout forms as the rotating funnel draws up water. Continue reading