Island Climate Update 80 - May 2007

Climate Change: the Intergovernmental Panel on Climate Change 4th Assessment Report – The South Pacific
Pene Lefale1, Michele Hollis2 and Jim Salinger3
This article highlights some of the key findings from the Small Islands chapter, released in April 2007, of Working Group II of the Intergovernmental Panel on Climate Change (IPCC), which includes material on the Pacific.
Working Group II identifies small islands, including those in the South Pacific, as one of four regions of the world likely to be especially affected by climate change.

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 80 – May 2007
April’s climate
South Pacific Convergence Zone (SPCZ) further north than normal in the west
Wet throughout southern Tonga, and parts of Fiji, with enhanced convection over Vanuatu and Tuvalu
Suppressed convection and low rainfall over Eastern Kiribati, Tokelau, the Northern Cook Islands, Samoa, and the Marquesas Islands
Warmer than normal in Samoa, Northern and Central French P

Climate developments in April 2007
 
Outgoing Long-wave Radiation anomalies for April 2007. (Click for enlargement and detail)
The South Pacific Convergence Zone (SPCZ) was generally further north than usual, extending from Papua New Guinea to Tuvalu, and then towards Niue. A region of weakly enhanced convection occurred over Vanuatu, Tuvalu, Fiji, and Tonga.

Tropical rainfall outlook: May to July 2007
 
Rainfall outlook map for May to July 2007. (Click for enlargement)
Enhanced convection is likely over the Solomon Islands and the Southern Cook Islands, where rainfall is expected to be above average.
Near or above average rainfall is expected from Papua New Guinea southeastwards to the Pitcairn Island, including Wallis and Futuna, Samoa, the Northern Cook Islands, Society Islands, Austral Islands, and Tuamotu Islands.
Suppressed convection is expected over Eastern Kiribati, where rainfall is likely to be below average.

Tropical cyclones
Tropical cyclone (TC) Cliff was the only named tropical cyclone to occur in the Southwest Pacific in April; there have been a total of six TCs so far this season, for the region east of 150°E. TC Cliff developed near northern Fiji and tracked southeast over 4–6 April, with maximum sustained wind speeds reaching 100 km/h.

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 produced by NIWA and made possible with financial support from the New Zealand Agency for International Development (NZAID), with addi