Enhancement of near-annual variability in the equatorial Pacific in 2000–2008
Like the El Niño Southern Oscillation (ENSO), the near-annual mode is an air–sea coupled mode of the tropical Pacific that can emerge within a relatively cool mean state. It is documented here from satellite observations over the 2000–2008 period based on a covariance analysis between wind stress an...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-04-01
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| Series: | Advances in Geosciences |
| Online Access: | http://www.adv-geosci.net/33/13/2013/adgeo-33-13-2013.pdf |
| Summary: | Like the El Niño Southern Oscillation (ENSO), the near-annual mode is an
air–sea coupled mode of the tropical Pacific that can emerge within a
relatively cool mean state. It is documented here from satellite
observations over the 2000–2008 period based on a covariance analysis
between wind stress and zonal current anomalies. It is shown that
near-annual variability is enhanced over the last decade. The signature of
this mode consists of a zonal seesaw pattern for zonal current with
westward (eastward) anomalous currents in the western (eastern) equatorial
Pacific. A composite analysis allows identifying the peak and transition
phases of this mode, particularly active over 2000–2004. It is suggested
that the reduction of the interannual variability in the eastern Pacific
over the last decade may be related to the enhancement of the near-annual
mode. |
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| ISSN: | 1680-7340 1680-7359 |