Island Climate Update 95 - August 2008

Average rainfall rate (mm day-1) during (top) all of 2007 and January 2007 (bottom).
Pacific Intertropical Convergence Zones during 2007
Dr. A. Brett Mullan, National Institute of Water & Atmospheric Research, New Zealand
There are two prominent convergence zones in the Pacific: the ITCZ in the Northern Hemisphere between 5°N–10°N, and the South Pacific Convergence Zone (SPCZ) that extends southeastward from near the Solomon Islands (10°S, 160°E) to near 30°S, 140°W.

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 95 – August 2008
July’s climate
The South Pacific Convergence Zone (SPCZ) was not as well-defined in July as in previous months.
Very suppressed convection from Western Kiribati to Eastern Kiribati and south of the Equator from the Solomon Islands to the Northern Cook Islands.
Below normal rainfall for Tonga, Niue, the Southern Cook Islands, and New Caledonia.
El Niño/Southern Oscillat

Climate developments in July 2008
Outgoing Long-wave Radiation anomalies for July 2008. (Click for enlargement and detail)
The South Pacific Convergence Zone (SPCZ) exhibited diminished activity in July relative to previous months. Only a small region of enhanced rainfall was observed in satellite data during July 2008, centred near Papua New Guinea and the Solomon Islands. A region of suppressed convection expanded along the Equator relative to last month, and extends from Western Kiribati to Eastern Kiribati including Tuvalu, Tokelau, and the Northern Cook Islands.

Tropical rainfall outlook: August to October 2008
Rainfall outlook map for August to October 2008. (Click for enlargement)
Sea surface temperature outlook map for August to October 2008. (Click for enlargement)
La Niña conditions have dissipated in the equatorial and subtropical southwest Pacific.

Tropical Pacific rainfall - July 2008
Territory and station name
July 2008 rainfall
total (mm)
July 2008 percent
of average
Australia
Cairns Airport
52
179
Townsville Airport
95
680
Brisbane Airport
91
145
Sydney Airport
90
71
Cook Islands
Penrhyn
112
80
Aitutaki
N/A
N/A
Rarotonga Airport
30
29
Fiji
Rotuma Island
453
195
Udu Point
101
114
Nadi Airport
73
159
Nausori
99
85
French Polynesia
Hiva Hoa, Atuona
125
80
Bora Bora
35
47
Tahiti – Faa’a
70
133
Tuamotu, Takaroa
62
76
Gambier, Rikitea
157
101
Tubuai
143
99
Rapa
367

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