Ground Cover Supplement : GC Supplement - Climate forecasting
14 Forecast skill 14 by oscar alves VariatioNs iN sea-surface temperature (sst) of the tropical indian ocean are a major source of climate variability across western and south-eastern australia. known as the indian ocean Dipole (ioD) these differences in sst drive atmospheric variations that, in turn, affect australian weather patterns and rainfall events across grain-growing regions. while the Predictive ocean atmosphere Model for australia (PoaMa) model has a high level of skill in predicting another key driver of regional australian rainfall – the el Niño–southern oscillation (eNso) – its ability to predict the ioD is significantly lower. the GrDc’s Managing climate Variability research set out to answer why the ioD is less predictable than eNso, with the aim of improving the capacity of PoaMa to predict the ioD and its impacts on weather patterns across regional australia. the PoaMa project had two components. first, researchers evaluated how successfully PoaMa could predict historical sst patterns compared with other international climate models. the results showed that PoaMa was not alone in its reduced ability to predict temperature differentials in the indian ocean. all models, including PoaMa, have significantly higher skill in predicting the impact of temperature changes in the Pacific ocean. since a large proportion of the indian ocean ocean observations drive forecast skill bureau of meteorology research is trying to understand how the temperature and salinity of the indian ocean drives australian weather patterns Monsoon onset prediction sought via poaMa The northern Australian monsoon season generally lasts from late December to March. It is associated with the inflow of moist west to north-westerly winds into the monsoon trough, producing convective cloud and heavy rainfall over northern Australia. These moisture-laden winds originate in the Indian Ocean and South-East Asian waters. The north Australian rainy season encompasses the monsoon months and can extend several months on either side. Bureau of Meteorology (BoM) research has tested the potential of the Predictive Ocean Atmosphere Model for Australia (POAMA) version 2.4 to predict northern rainy-season rainfall. The aim of the work has been to develop a prediction strategy for the onset of the northern rainy season, as defined by an accumulation of 50 millimetres of rainfall from 1 September. Defined in this way, the onset date corresponds to about the time that the grass turns green in northern Australia, making forecasts particularly valuable for growers. POAMA’s skill was relatively high at simulating and predicting the year-to-year variability associated with the El Niño– Southern Oscillation and onset dates of the rainy season. However, it was unable to reproduce the observed 50-year trend to wetter conditions (and earlier rainy season onset dates) in north-western Australia. More recently, researchers have tested POAMA’s ability to predict the week-to-week variations in northern Australian weather. By concentrating on an area-averaged index of monsoon convective cloudiness, useful skill can be achieved out to about 30 days. Some of these week-to-week fluctuations are driven by the passage of the Madden–Julian oscillation as it passes northern Australia. This work is part of research that aims to fill the gap between weather forecasts and longer-term seasonal outlooks. – MATTheW WheeleR grDC research Code mCv00032 more information: Matthew Wheeler, BoM, 03 9669 4068, firstname.lastname@example.org photo: arthur Mostead flowering forecasts help Manage risk Increasing average temperatures across the Australian wheatbelt over the past 50 years have sped up the flowering time and maturity rate of wheat varieties. CSIRO research is investigating how current Australian wheat photo:Janetpatersonphoto:grdC CSIRO research is determining if there is sufficient genetic variation in flowering time and tillering behaviour among Australian wheat varieties to adapt to predicted changes in climate. Accurate weather forecasts rely on the most up-to-date conditions of the ocean, land and atmosphere. Storm cloud formations near Boggabilla in north-west NSW.
GC Supplement - Grain and Graze
GC Supplement - Profitable pulses and pastures