Island Climate Update 23 - August 2002

23 March 2007 - 12:58pm

Science Centres: Climate

August

Monthly climate

ENSO & SST

Forecast validation

Three-month outlook

Feature article

Data sources

Feature article
Correlation between the annual Southern Oscillation Index (SOI) and annual mean SLP, surface temperature and percentage of normal precipitation, for the most recent negative and positive phase of the IPO. (Click to enlarge) Part 2 – Interdecadal Pacific Oscillation – Modulating ENSO A Gosai, B Mullan, J Renwick and J Salinger The Interdecadal Pacific Oscillation (IPO) modulates teleconnections with ENSO in a complex way, strengthening relationships in some areas and weakening them in others. Although the IPO and ENSO operate on different time scales, they are similar in their

August
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region. Number 23 – 7 August 2002 July’s Climate: The South Pacific Convergence Zone (SPCZ) extended east from the Solomon Islands to the north of Samoa, being displaced south of its mean position. It continued to be weak with little activity further east in the Southwest Pacific.

Forecast validation
Forecast validation Forecast period: May to July 2002 Rainfall was projected to be above average in Western and Eastern Kiribati, as well as Tonga, and average or above average in Vanuatu and in southern and central French Polynesia. Below average rainfall was projected from the Northern Cook Islands to the Marquesas. Average rainfall was forecast for other areas. Rainfall was higher than expected in Samoa and the Marquesas Islands, and lower than expected in New Caledonia, Tonga, Kiribati, the Southern Cook Islands, and the Society Islands.

ENSO & SST
ENSO and Sea Surface Temperatures Warm seas persist throughout much of the Pacific The chance of an El Niño remains high In the equatorial Pacific, a band of anomalously warm water persists about the dateline (at least 1.5°C above average).Although much of the Southwest Pacific remain about 0.5°C–1.0°C above average, there is cooling in the Coral Sea particularly north of New Zealand and around New Caledonia.

Monthly climate
Enhanced convection from the Solomon Islands southeast to Niue Below average rainfall from Australia to New Caledonia and from Eastern Kiribati to the Cook and Society Islands The SPCZ moved further south in July, to extend east from the Solomon Islands through southern Tuvalu to the north of Samoa, being displaced south of its mean position. It continued to be weak with little activity further east in the southwest Pacific.

Three-month outlook
Rainfall outlook for August to October 2002 Above average rainfall in equatorial latitudes from west to east Average or above average rainfall in Tuvalu, the Society Islands and Pitcairn Average or below average rainfall in Papua New Guinea, New Caledonia, Samoa, Cook Islands, and the Marquesas Islands Mainly average rainfall in other areas The El Niño is expected to have an influence on the rainfall in some areas, particularly along the equator and in the Coral Sea. The South Pacific Convergence Zone is expected to remain fairy inactive east of the date line, with average or below ave

Data sources
Sources of South Pacific rainfall data This bulletin is a multi-national project with important collaboration from the following Pacific nations: American Samoa Australia Cook Islands Fiji French Polynesia Kiribati New Caledonia New Zealand Niue Papua New Guinea Pitcairn Island Samoa Solomon Islands Tokelau Tonga Tuvalu Vanuatu Requests for Pacific island climate data should be directed to the Meteorological Services concerned. Acknowledgements This bulletin is made possible with financial support from the New Zealand Agency for International Development (NZAID), Wellington, New Zealand, wi