Science Centres: Climate

Climate developments in June 2003

SPCZ active with extremely high rainfall over French Polynesia
Reduced convection persists along the equator
Record low rainfall in parts of Tonga and Niue

The SPCZ was displaced further south than average east of the Date Line. As a result enhanced convection occurred over much of French Polynesia and at least 200% of average rainfall throughout much of the Society and northern Austral Islands. Rainfall totals were also enhanced, being 125% or more than average in most areas from the Solomon Islands to Tuvalu and east to the Cook Islands, as well as Pitcairn Island and much of Vanuatu. The high rainfall recorded in northern Vanuatu was largely due to tropical cyclone Gina.

An elongated region of suppressed convection persisted along the equator extending from Indonesia across to Eastern Kiribati (with rainfall totals generally less than 50% of average there) and further east. Another region of suppressed convection, with rainfall generally less than 50% of average with low totals in places, affected Fiji, Tonga and Niue. June was Niue’s third consecutive month with below average rainfall.

Air temperatures were above average over New Caledonia, Vanuatu, and the Marquesas Islands, average or below average over Fiji, and near average elsewhere.

Climate extremes in June 2003

Outgoing Long-wave Radiation (OLR) anomalies, in Wm-2 are represented by shaded areas, and rainfall percentage of average, shown by numbers. High radiation levels (yellow) are typically associated with clearer skies and lower rainfall, while cloudy conditions lower the OLR (blue) and typically mean higher rainfalls. The June 2003 position of the South Pacific Convergence Zone (SPCZ), as identified from total rainfall, is indicated by the solid green line. The average position of the SPCZ is identified by the dashed green line. Data source: NOAA-CIRES Climate Diagnostics Center.