 |
| Titel |
Possible link the tropical SST anomalies and Arctic Oscillation on the low-frequency timescales during the boreal winter |
| VerfasserIn |
S.-M. Lim, S.-W. Yeh |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062504
|
|
|
|
|
|
| Zusammenfassung |
| To examine possible mechanism on the low-frequency changes in Arctic Oscillation
(AO) we investigate the relationship between Aleutian low (AL) and AO during
the boreal winter (November-December-January-February-March, NDJFM) using
NCEP/NCAR reanalysis1 dataset for the period of 1950-2011. It is found that an
increase of warm pool sea surface temperature (SST) in the western tropical Pacific is
associated with a northward shift of a center of AL on the low-frequency timescales via
tropics-midlatitude atmospheric teleconnections. A composite analysis indicates that a shift
of AL in the meridional direction is associated with the North Pacific Oscillation in
the North Pacific. Furthermore, the spatial structure of sea level pressure anomaly
when a center of AL is shifted to the north is a reminiscent of a positive phase of
AO in the high latitude. Detail analysis indicates that a shift of AL center in the
meridional direction is associated with the change of AO index with a lagged time on
the low-frequency timescales. We discuss how the northward shift of AL center
is associated with a positive AO-like sea level structure in the high latitudes, and
recent phase change of AO index in spite of gradual warming of warm pool SST. |
|
|
|
|
|
|