Monthly climate

Climate developments in December 2002
El Niño continues to enhance convection over Kiribati
Suppressed convection from Papua New Guinea to the Southern Cook Islands
The SPCZ was displaced further east than average, with enhanced convection from Tuvalu southeast to the Society Islands. This region merged with the Inter-tropical Convergence Zone (ITCZ), which was enhanced over Kiribati, and in the central equatorial Pacific just north of the equator.

28 February 2007

Climate developments in December 2002

El Niño continues to enhance convection over Kiribati

Suppressed convection from Papua New Guinea to the Southern Cook Islands

The SPCZ was displaced further east than average, with enhanced convection from Tuvalu southeast to the Society Islands. This region merged with the Inter-tropical Convergence Zone (ITCZ), which was enhanced over Kiribati, and in the central equatorial Pacific just north of the equator. Episodes of equatorial surface westerlies that have been enhancing the ENSO linked convection over Kiribati, weakened further, reaching their lowest frequency at Tarawa (24% of observations) since June 2002.

December rainfall was at least 125% of average (and approximately 300 mm, or more) over a broad region from Western and Eastern Kiribati, southeast to Pitcairn Island, including the Society Islands of French Polynesia, and the Northern Cook Islands.

The large region of suppressed convection persisted over Indonesia, extending to Papua-New Guinea, the Coral Sea, the Solomon Islands, Vanuatu and the north of New Caledonia, where rainfall totals were less than 50% of average in many areas. Rainfall was also less than 50% of average in many areas from Fiji to Tonga, as well as the Marquesas Islands in northern French Polynesia.

A new high maximum temperature record (32.4°C) was set at Hao, French Polynesia during December. It broke the record set in 1964 (32.3°C).

Climate extremes in December 2002

Country Location Rainfall (mm) % of average Comments
Australia Willis Island 11 12 Well below average
Vanuatu Pekoa 38 14 Extremely low
New Caledonia lle Art, Beep 33 22 Extremely low
Fiji Nadi Airport 26 14 Extremely low
Fiji Ono-I-Lau 9 7 Record low
New Zealand Raoul Island 18 14 Well below average
French Polynesia Hiva Hoa, Atuona 7 9 Record low
Country Location Max Air Temp (°C) Date Comments
French Polynesia Hao 32.4 Record High
Outgoing Long-wave Radiation (OLR) anomalies, in Wm-2 , for December 2002 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 December 2002 position of the South Pacific Convergence Zone (SPCZ), as identified from total rainfall, is indicated by the solid green line. The average climatological position of the SPCZ is identified by the dashed green line. Data source: NOAA-CIRES Climate Diagnostics Center.

Island Climate Update 28 - January 2003