An exploratory investigation of the relationship between decadal rainfall and climate indices

Abstract

This study presents an exploratory investigation to assess if long-term variations in sea surface temperature (SST) and mean sea level pressure (MSLP) are related to decadal rainfall. Improved knowledge of decadal rainfall would assist with decision making in the sugar industry, e.g. it could help in deciding whether to purchase a wet- or dry-weather harvester, and which cane variety to plant. To investigate the correlation between rainfall and the ocean-atmospheric indices, 10-yearly running averages for June-November (relating to harvester choice) and January-December (in connection with which variety to plant) rainfall for the Tully (North Queensland), Plane Creek (Central Eastern Queensland) and Harwood Sugar Mills (Northern NSW) were used as well as five indices derived from SST and MSLP data. A strong relationship between decadal rainfall and these indices was uncovered. It is recommended, however, that further research be conducted to identify if this relationship is simply a statistical artefact, or if improved knowledge of the physical phenomena underpinning the statistical relationships can be uncovered.