The Australian Bush Fires: What you need to know

If you pay attention to the news, you probably have heard about the dangerous wildfires that have burning across Australia and having great impacts on human and animal life alike. We thought it would be good to put this event in context for you, since some here in the U.S. may not be familiar with brush fires in Australia.

Just like here in the United States, there are seasonal conditions which contribute to the occurrence and growth of brush fires (wildfires as we often refer to them). In northern Australia, the most favorable conditions usually occur during the dry season of winter and spring. Further south, brush fires tend to occur in late summer and autumn. Just remember that Australia is in the Southern Hemisphere, so ‘northern’ locations are closer to the tropics, and ‘southern’ locations are closer to the poles. Also, the seasons are reversed, so that summer in Australia is occurring during winter here in the United States.

For reference, cities in southern Australia such as Cairns and Darwin are around 15 degrees south of the equator (the equivalent of where Honduras and Nicaragua are located in the northern hemisphere). Perth (on the west coast) is about 30 degrees south, which is roughly the equivalent of the location of Orlando, FL from the equator in the northern hemisphere. Sydney and Melbourne (on the east coast of Australia) are about the same distance from the equator as Atlanta and Philadelphia, respectively.

Source: http://www.anbg.gov.au/maps/aust-usa-map.jpg

As you can see, Australia is much larger in size than most people realize; the continent/country of Australia is comparable in area to the continental United States! So, where are the fires burning? As you can see by this image, the fires are burning in many places, but are most concentrated all up and down the east coast (newer fires are denoted in red, older fires in oranges and yellows).

Courtesy: myfirewatch, government of western Australia.

The conditions which result in increased fire danger are the same as here in the U.S.: hot, dry conditions over extended periods of time, along with strong gusty winds. Cold frontal passages, known as ‘cool changes’ in Australia, can result in changes of wind direction that cause changes in the behavior of ongoing fires. According to the Australian Bureau of Meteorology, climate change is increasing the frequency and severity of favorable brush fire conditions, by increasing the frequency of extreme heat events and extending the ‘fire weather’ season earlier into the spring.

Satellite imagery from January 4, 2020 showing smoke from the wildfires extending off the east coast of Australia. Courtesy: NASA Earth Observatory.

So, what has made this fire season (recall Australia is currently in mid-summer) so devestating? In a climate statement released on January 9, the Australian Bureau of Meteorology reports that, 2019 ranks as both the warmest and driest year on record in terms of areal average temperature and precipitation across Australia.

Courtesy: Australian Bureau of Meteorology.

Additionally, rainfall was below average across much of southeastern Australia, with many areas seeing record dry conditions. In fact, some parts of Australia have been in dry or drought conditions since 2017
(see the full report here).

Courtesy: Australian Bureau of Meteorology.

The impacts of the fires have been far-reaching. In New South Wales (where Sydney is located), smoke has been creating severe haze and poor air quality for numerous residents in Sydney and up and down the east Coast. Estimates state that as much as half of the koala population has been affected. At least 24 people have been killed, and many more have had to evacuate.

Smoke in Sydney on December 10, 2019. Courtesy: BBC.

The Associated Press reports that over 12 million acres have been burned across the country, with approximately 7 million of those in New South Wales. Ash and debris from the fires can even be seen on the snow in the mountains of New Zealand.

So how long will the fire danger continue? As of January 9, the Australian Bureau of Meteorology reports that, while fire danger conditions are still expected to remain elevated, the extreme conditions that have been occurring will have moderated somewhat.

The U.S. National Weather Service has deployed several specially trained Incident Meteorologists (IMETs) to Australia to assist with fire weather forecasting.

For the latest updates, be sure to check out the Australian Bureau of Meteorology website. There are numerous resources and up-to-date forecasts.

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