| || || Rain and rainfall -- Oceania|
| || || Analysis of daily temperature and rainfall data for the South West Pacific from 1982 to 2011|
Author: Swamy, Avengeleen Sarika
Institution: University of the South Pacific.
Subject: Climatic changes -- Oceania, Atmospheric temperature -- Oceania, Rain and rainfall -- Oceania
Call No.: pac QC 903 .2 .O3 S932 2012
Copyright:10-20% of this thesis may be copied without the authors written permission
Abstract: Analysis of historical climate data provides important insight into the climatic changes already occurring. The objective of this study was to examine the available data within the Pacific Islands to quantify the climate changes that are already underway. Climate data from 14 stations in 7 countries throughout the south west Pacific was examined to determine trends in key climatic variables including, maximum, minimum and mean temperature, rainfall anomalies, hot and very hot days, hot and very hot nights, dry, wet and very wet days for the past 30 years (1982 to 2011) using the R software. The countries that are part of this study are Fiji, the Solomon Islands, Tonga, Tuvalu, Vanuatu, and the French Territories of New Caledonia and Wallis & Futuna. All 14 stations throughout the SW Pacific show a positive trend in maximum, minimum and mean temperature anomalies over the last 30 years, ranging from 0.01°C per year to 0.07°C per year. Highest increase of maximum, minimum temperatures and rainfall values were obtained over Auki (Solomon Islands), Nui (Tuvalu) and Pekoa (Vanuatu) at the rates of 0.06°C per year, 0.07°C per year and 45.95mm per year, respectively. The number of hot days has increased at all stations with the highest increase at Auki (Solomon Islands) by 8 days per year. The number of cool nights has decreased at all stations with Funafuti (Tuvalu) recording the highest loss of 5 cool nights per year. Rainfall anomaly trends over the study period were more variable. Some stations show decreasing trends (-34.52mm per year to - 2.22mm per year) and some show increasing trends (2.12mm per year to 45.95mm per year). The number of dry days has decreased at all the stations. The number of wet days did not show a significant change at all the station except for Nausori (Fiji) and the stations at Vanuatu where it has increased by 1 day per year and decreased at Nui (Tuvalu) by 2 days per year. The number of very wet days did not show a significant change at all the station except for Nui (Tuvalu) where it has decreased by 2 days per year. The results demonstrated that much of the variation throughout the south west Pacific was driven by the South Pacific Convergence Zone (SPCZ). Sites located north east of the SPCZ showed decreasing rainfall and sites south west of the SPCZ showed increase in rainfall. The current negative phase of the Interdecadal Pacific iv Oscillation (IPO) has shifted the SPCZ south and west-ward. These results emphasize the need to better understand the SPCZ and the IPO and their response to future climatic changes in the south west Pacific.