http://theconversation.com/indian-ocean-linked-to-bushfires-and-drought-in-australia-20893
"Cooling oceans off the coast of Indonesia can create bushfire weather in Australia.
In a study in Nature Geoscience, we show that extreme weather events in Australia such as drought and bushfire are linked to temperature changes in the Indian Ocean. Much like El Niño in the Pacific Ocean, the [Indian Ocean Dipole] has far-reaching consequences, and these effects are likely to strengthen under climate change.
What is the Indian Ocean Dipole?
Like El Niño, the Indian Ocean Dipole (IOD) is an interaction between the ocean and atmosphere.
The IOD appears and develops in the Southern Hemisphere winter and matures in spring. In its positive phase, which is the one that interests us most, sea temperatures off the cost of Sumatra and Java are lower than normal. Meanwhile in the western equatorial Indian Ocean, off the coast of Kenya, sea temperatures are warmer…
These seemingly small changes in sea temperature have profound effects on the atmosphere. Convection — rising warm, moist air — and rainfall tend to follow the warmest sea temperatures. So changes in sea temperature dramatically alter atmospheric circulation and rainfall distribution.
The result, in the case of the IOD, is extreme weather in many parts of the world, including severe droughts in Indonesia and devastating floods in East African countries.
For Australia, our research confirmed links between this Indian Ocean phenomenon and extreme weather events in southeast Australia, for example, bushfires such as those that occurred on Black Saturday.
During a positive IOD event, south east Australia sees decreased rainfall and increased temperatures. This is because much of the moisture supplying rainfall over south east Australia in winter and spring come from the tropical eastern Indian Ocean. Less rain and clear skies lead to higher temperatures than normal.
Cool waters over the western Indian Ocean cause drought and extreme fire conditions in Australia. CSIRO
…
Our major bushfires in summer have been linked with a positive IOD in winter and spring, and therefore the IOD offers a way of predicting summer bushfire conditions. This research enables us to better anticipate drought and increased bushfire risk.
This is because we have some four to six months of lead time before the fire season. An IOD in winter and spring is a warning sign of higher than normal fire risks in the upcoming summer.
In future climate, a decline in spring rainfall and a rise in temperature induced by an IOD event, exacerbated by a long-term drying trend in a warming climate, will greatly increase the risk of major bushfires."
Australia same size as United State minus Alaska is little understood by most of the world. God bless
