Natural Climate Patterns

Uncommon atmospheric circumstances spawned a pair of tropical cyclones in the western Pacific—one on either side the equator, at nearly the same longitude, at nearly the same time. Why are twin cyclones more common during El Niño?

Sunday, May 1, 2011

  • Above-average sea surface temperatures, a natural cycle of increased hurricane activity, and a fading La Nina have influenced the 2011 Atlantic hurricane outlook.

  • Near the Earth’s equator, solar heating is intense year round. Converging trade winds and abundant water vapor all combine to produce a persistent belt of daily showers known as the Intertropical Convergence Zone.