STATE OF THE CLIMATE IN 2009

Table 7.3. Average temperature anomaly (°C relativeto 1971–2000 base period) for 2009 recorded byPacific Islands Met Services. (Source: NOAA/NCEPCPC CAMS.)Station Island 2009 AnomalyPeokoa Airport (Santo) Vanuatu +0.4Noumea New Caledonia +0.6Rotuma Fiji +0.1Nadi Airport Fiji +0.2Hihifo Wallis +0.6Rarotonga Cook Islands -0.3Tahiti-Faaa Societ Islands +1.4Takaroa Tuamotu Island +0.5Rapa Austral Island +0.9Norfolk Island Aero Australia +0.3was recorded over Gambier and Tuamotu islands andalong the equator across western Kiribati, Tuvalu,Tokelau, and eastern Kiribati. For the second year ina row, Tarawa and Banaba islands were particularlyaffected by significant drought conditions duringthe first six months of the year, highlighted by anumber of record-low rainfall totals. Rainfall fromJanuary to April was above average over the SolomonIslands, Vanuatu, New Caledonia, Fiji, Tonga, Niue,and the Southern Cook Islands, while rainfall deficitswere significant along the equator and over FrenchPolynesia.The rainfall pattern observed over the SouthwestPacific was heavily influenced by the state of ENSO.During the first three months of 2009 convectionwas suppressed along the equator from west of Nauruacross Western Kiribati to the date line, while theSouth Pacific Convergence Zone (SPCZ) was furthersouth and west of its mean location, extendingfrom Papua New Guinea and northeasternQueensland to the New Caledonia archipelago(165°E). This La Niña dipole was less intense,and the area of maximum convective activitywas not as spread out as during 2008, when theLa Niña event resulted in the SPCZ expandingas far southeast as the Southern Cook Islands(160°W). In April 2009, the SPCZ shiftedeastward, contributing to enhanced convectiveactivity from Wallis and Futuna (175°W)to the Austral Islands (150°W). In May, theSPCZ weakened significantly, stalling overparts of Vanuatu, New Caledonia, and Fiji,southwest of its normal position. Concurrently,a zone of suppressed deep convectionwas present near Western Kiribati andsouth of the equator, extending east throughNauru and Eastern Kiribati. From June toOctober, the SPCZ stagnated southwest ofits normal position and contracted towardNorthern Papua New Guinea. Enhancedconvection was largely absent from theregion during the austral winter, while thearea of suppressed convection contractedtowards the central part of the SouthwestPacific, near Tokelau. During Novemberand early December, above-average convectiveanomalies along a southwest-displacedSPCZ were seen near northern Vanuatu,northern Queensland, and the eastern edgeof Papua New Guinea, before becoming establishedeastward across Western Kiribati,Fiji, Tonga, Austral Islands, and the PitcairnIslands as El Niño conditions took hold. Suppressedconvection was observed during November in thecentral part of the Southwest Pacific near Fiji andSamoa, before extending towards the northern CookIslands and French Polynesia during December.(iii) Notable eventsFrom January to March, under the influence ofLa Niña conditions, stronger-than-usual easterlysurface winds prevailed along the equator across theKiribati archipelago. From May until the end of theyear, the trade winds weakened and hence westerlywind anomalies covered large portions of the equatorialPacific, with the exception of some areas nearthe date line.Fourteen synoptic-scale low-pressure systemsformed in the Southwest Pacific in 2009. In January,record-breaking rainfall was recorded in Viti LevuFig. 7.55. Percentage of mean annual rainfall for 2009 (1979–95base period) for the Southwest Pacific. (Source: NOAA NCEPCPC CAMS.)S186 | juNE 2010