Fire Down Under

Here at HOOT we spend a lot of time discussing Oklahoma and the Great Plains, but this month we're going to leave Oklahoma, the United States, and even the Northern Hemisphere to talk about one of the major weather stories of the day—the massive wildfires that have been burning in southern Australia for over a month. Oklahoma is no stranger to wildfires; in fact, they are relatively common, particularly during the dry winter months. The Australian blazes, however, are in a league of their own—so far they have killed more than 200 people, injured at least 500, destroyed over 2000 homes, and caused damage likely to reach into the billions of dollars. To examine these fires is to examine a convergence of weather, climate, and human impacts; so get ready for a dose of climate and society and come with us as we focus on the “down under”. We'll begin with an overview of the fires themselves.

The first of the wildfires began during the last week of January and the first week of February 2009, with the largest fires in the rural Gippsland region of Victoria province. The situation worsened drastically on Feb. 7 and 8, when near-record heat and lightning combined to start many more blazes in southeast Australia. These fires have continued to burn, some for more than a month, and only on March 4 were some residents allowed to return to houses in some of the affected areas, as cooler weather and rain brought much-needed relief to the burned region. Investigators have found that some of the wildfires were the result of arson, though the majority were started by natural causes (most notably lightning).

Climate played a large role in setting the stage for the wildfires. Southeastern Australia is currently suffering a decade-long drought among the worst the region has ever observed since records were first collected in the 1850's. According to the Australian Bureau of Meteorology, much of the area affected by the wildfires has received less than 2mm (0.08 in) of rain thus far during 2009. Australia, being largely dominated by tropical and subtropical weather patterns, is highly susceptible to climate variations. Much of the nation is affected by a seasonal monsoon pattern. In addition, Australia is strongly affected by the El Niño-Southern Oscillation (ENSO). During El Niño years, the usual tropical rainfall experienced over Australia and Indonesia shifts eastward, out to sea, following the eastward shift of the warm, Pacific surface waters. Variations in ENSO and the monsoon circulation can exacerbate existing drought conditions.

Weather also contributed heavily to the severity of the wildfires. During the last week of January and the first week of February, a slow-moving subtropical high pressure system in the Tasman sea brought southeastern Australia a major heat wave, culminating on Feb. 6th, when a high of 46.4C (115.5F ) was recorded in Melbourne. The extreme heat combined with the existing drought conditions to send the Forest Fire Danger Index to a record value of 190 (anything above 25 is considered “high danger”, and anything in excess of 50 is considered “extreme”).

Though the loss of life and exceptional damage caused by the wildfires is tragic, the disaster has evoked outpourings of support worldwide, and resulted in important discussions on fire and climate policy. Several countries, including the United States and New Zealand send firefighters to help battle the blazes, while many other nations, including Indonesia and Papua New Guinea have set aside funds to aid victims and help with rebuilding efforts. The fires have also lead the province of Victoria to consider improved building codes in fire-prone areas. Modern technology has also been in the spotlight; on March 3rd police in Victoria sent more than 3 million text messages to Victoria residents, alerting of high fire danger. According to the Sydney Morning Herald, this test was the first of its kind.





Story is © Nate Snook, 2009