A new index for variations in the position of the South Pacific convergence zone 1910/11-2011/2012
Article
Article Title | A new index for variations in the position of the South Pacific convergence zone 1910/11-2011/2012 |
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ERA Journal ID | 1962 |
Article Category | Article |
Authors | Salinger, M. J. (Author), McGree, Simon (Author), Beucher, Florent (Author), Power, Scott B. (Author) and Delage, Francois (Author) |
Journal Title | Climate Dynamics |
Journal Citation | 43 (3-4), pp. 881-892 |
Number of Pages | 12 |
Year | 2014 |
Publisher | Springer |
Place of Publication | New York, United States |
ISSN | 0930-7575 |
1432-0894 | |
Digital Object Identifier (DOI) | https://doi.org/10.1007/s00382-013-2035-y |
Web Address (URL) | https://link.springer.com/article/10.1007%2Fs00382-013-2035-y |
Abstract | Quality controlled and recently homogenised mean sea level pressure records for the South Pacific are used to specify the location and variability of the South Pacific convergence zone (SPCZ) during the austral warm season (November-April). The SPCZ is the world's largest rainfall band during the austral summer, when it dominates the climate of the South Pacific. A new index called the South Pacific convergence zone index (SPCZI) is derived, and is shown to be coherent with changes in low level wind convergence associated with the SPCZ. This index replaces the earlier SPCZ position index because it uses higher quality mean sea level pressure data than the superseded index and extends the time series further forward in time. The SPCZI allows interannual to decadal variability in the climate of the South Pacific to be tracked for more than a century from 1910/1911 to 2011/2012. During El Niño episodes the SPCZ is displaced by about 1°-3° east, and La Niña events 1°-3° west of the mean position on average. The index indicates a striking movement eastward for the period 1977/78-1998/99, compared with 1944/45-1976/77 in association with the Interdecadal Pacific oscillation (IPO). The eastward movement of the SPCZ in the late twentieth century is related to significant precipitation trends in the South Pacific region. Since 1998/99 the SPCZ has regressed westward with the negative phase change of the IPO. The long-term trend in the SPCZI is very small relative to the interannual to decadal variability and is not statistically significant, suggesting that there has been little overall change in the mean position of the SPCZ over the past century. © 2014 Springer-Verlag Berlin Heidelberg. |
Keywords | air-sea interaction; climate variability; El Nino; Interdecadal Pacific Oscillation; La Nina; New index; South Pacific convergence zone |
ANZSRC Field of Research 2020 | 370202. Climatology |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | University of Auckland, New Zealand |
Australian Bureau of Meteorology | |
Meteo France, France | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q66y9/a-new-index-for-variations-in-the-position-of-the-south-pacific-convergence-zone-1910-11-2011-2012
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