Science Centres: Climate

Climate developments in May 2003

SPCZ further east, from Samoa to the Tuamotu Islands

Reduced convection along the equator

The SPCZ was displaced further east than average, with enhanced convection over Samoa and the Northern Cook Islands, and the Tuamotu Islands of French Polynesia. May rainfall was at least 125% of average (totalling 200-300 mm at most locations) throughout much of this region.

Rainfall totals were also 125% or more of average in parts of Vanuatu and New Caledonia. Rainfall was average to below average over Fiji.

An elongated region of suppressed convection (associated with rainfall totals generally less than 50% of average) extended along the equator from Nauru east across Kiribati, and to the north of the Marquesas Islands

Air temperatures were at least 0.5°C above average throughout much of the tropical Southwest Pacific, as far east as Pitcairn Island, and about 1.0°C above average between New Caledonia, and Vanuatu, as well as parts of central French Polynesia, consistent with the warmer than average seas. New maximum and minimum May temperature records were set at two sites in Fiji.

Climate extremes in May 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 May 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.