Estimates of soil moisture shown in the map (right) are based on monthly rainfall for one station in each country. Currently there are not many sites in the water balance model, but it is planned to include more stations in the future.
The information displayed is based on a simple water balance technique to determine soil moisture levels. Addition of moisture to the available water already in the soil comes from rainfall, with losses via evapo-transpiration. Monthly rainfall and evapo-transpiration are used to determine the soil moisture level and its changes. Please note that these soil moisture calculations were made at the end of the month, and for practical purposes, generalisations were made about the available water capacity of the soils at each site.
Fiji (Nadi) and Niue (Hanan) project significant soil moisture deficits. Soil continued to be moist at Tarawa, and was moderate at Rarotonga (Southern Cook Islands) and Apia (Samoa).
In contrast, conditions were very wet in both Eastern Kiribati and Western Kiribati. Tarawa and Kanton received 190% and
339% of normal rainfall, respectively. Rainfall was also near normal to well above normal in French Polynesia during October. In the Marquesas, 284% of normal rainfall (278mm) fell, and anomalies of more than 200% of normal were also recorded in Tuvalu. For the Solomon Islands, October saw near normal to well above normal rainfall, and 100%–230% or normal rainfall anomalies were reported at multiple sites.
The southerly circulation pattern resulted in lower than normal temperatures to the north of the Tasman Sea last month, and were particularly important for Fiji and New Caledonia. However in Australia, warmer than normal temperatures occurred in eastern Queensland.
Estimated soil moisture conditions at the end of October 2009, using monthly rainfall data. Soil moisture projections for individual Pacific Island countries are dependent on data availability at the time of publication.