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'La Niña' is a coupled ocean-atmosphere phenomenon similar to El Niño. During a period of La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 0.5ºC. By definition, an ''episode'' of La Niña is a period of at least 5 months of La Niña conditions. The name La Niña originates from Spanish, meaning "the little girl", analogous to El Niño meaning "the little boy".
La Niña is the opposite of El Niño, where the latter corresponds instead to a ''higher'' sea surface temperature by a deviation of at least 0.5ºC. El Niño is famous due to its possibly catastrophic impact on the weather along both the Peruvian and Australian coasts. Furthermore, La Niña is often preceded by a strong El Niño.

Contents

Effects of La Niña

Recent occurrences

See also

References

External links

Effects of La Niña

La Niña causes mostly the opposite effects of El Niño, for example, El Niño would cause a wet period in the Midwestern U.S., while La Niña would typically cause a dry period in this area.
Also, the presence of La Niña is often quoted by the National Hurricane Center to be a cause for increased Atlantic tropical cyclone activity, partly because of higher sea surface temperatures in the Atlantic basin. The hurricane season of 1995 is also likely to have been influenced by that year's La Niña conditions.

Recent occurrences

There was a strong La Niña episode during 1988-1989. La Niña also formed in 1995, and in 1999-2000. The last La Niña was a minor one, and occurred 2000-2001. In 2007, La Niña might develop, as mentioned by the NOAA in their 2007 Hurricane Season Outlook,^[1] but current conditions do not meet the requirements for an official La Niña.^[2][3]

See also

★ El Niño-Southern Oscillation (Main article on El Niño and the related Southern Oscillation, discussing the relation between these two and La Niña)

★ Walker circulation

References

1. 2007 Hurricane Season Outlook
2. NOAA East Pacific sea surface temperature monitoring
3. NOAA/Climate Prediction Center - discussion of current conditions

External links

★ La Niña episodes in the Tropical Pacific

★ Information page on El Niño-Southern Oscillation (ENSO)

★ List of El Niño and La Niña events since 1950