BYO Death Ray: Smoking bushfires are bad for your health

Bushfire smoke covers Melbourne.

Victoria has been hit by large bushfires, resulting in dangerous smog over Melbourne. Dylan is here to explain.

The recent mix of wind and heat over Victoria led to an emergency situation, with bushfires burning around the state. The after-effects of bushfires include smog or haze. This smog/haze has been blown over Melbourne and with many fires still burning, the smog is likely to continue. Haze is defined as “an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky”.

The smoke presents a serious health risk, and health authorities and organisations continue to urge residents to be vigilant and take action to protect their health and the health of others. EPA Victoria issued an alert to residents about this issue. Their advice is as follows:

• People with respiratory or cardiac disorders should take their medication and minimise strenuous outdoor activity on smog alert days.
• Avoid driving where possible. Consider public transport, cycling or walking.
• Do not burn off outdoors or light incinerators (most local councils have restrictions on burning off).

Victorian Chief Health Officer Dr Rosemary Lester released a statement saying that children and the elderly should decrease outdoor activity when smoke levels are high to prevent medical issues. “Where possible, this sector of the community should also limit the time spent outdoors,” Dr Lester said. “Anyone with a heart or lung condition should take their medication as prescribed by their doctor... People with asthma should [also] follow their asthma management plan.”

Hazey links

• In Victoria, www.emergency.vic.gov.au has up-to-date information on bushfires and other emergency situations.
• The Country Fire Authority (CFA) has an awesome website for kids, where you can explore a bushfire, play games and more.

2013 was HOT STUFF!

2013 was Australia's hottest year since measurements began. The average temperature across Australia was 21.8 °C, which is 1.2 °C above the long-term average (1961-1990) and 0.2 °C higher than the previous record year, 2005.

The year started hot, when on January 7 Australia recorded its hottest day ever, with an average maximum temperature across the country of 40.3 °C. January was also the hottest on record, as was the entire summer.

Other temperature records that were broken in Australia last year included the hottest winter day, the hottest spring average and the hottest September average.

Almost every day of the year was above average (in red)
Source: Bureau of Meteorology

BYO Death Ray: Top 10 science images of 2013

Hello everyone, Dylan here!

2013 has been out of this world... literally! Most of the top science images of 2013 were not taken on Earth. These have been hand-picked by me for Death Ray Science News. In no particular order, here are my top science images of 2013:

#1: The first image was taken by NASA's Cassini spacecraft, which has been orbiting Saturn since 2004. It shows the view of the Earth and Saturn on July 19 (the Earth is a little white dot to the bottom-right of Saturn - you can see it better by clicking on the image and making it bigger). Cassini was around 1.44 billion km away from Earth at this time.

Click on the image to see a much bigger version
Source: NASA/JPL-Caltech/SSI

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BYO Death Ray: NASA predicts ozone hole recovery in 2070

Congratulations to our first ever BYO (Build Your Own) Death Ray contributor. 13-year-old Dylan from Balwyn High School in Melbourne has sent us some good news in science - the recovery of the ozone layer. He also wins an iTunes voucher.

New research from NASA claims that the ozone layer may fully recover in around 2070. This was announced at a presentation on Wednesday during the annual American Geophysical Union meeting in San Francisco.

The ozone layer over Antarctica.
The blue area is the 'hole'.
Image from NASA/Ozone Hole Watch.

It has been 26 years since the Montreal Protocol, which in 1997 led to 197 countries banning the chemicals that harm the ozone layer. Susan Strahan of NASA's Goddard Space Flight Center said that the harmful chemicals in the atmosphere are dropping because of the protocol but have not yet dropped to the point where the ozone layer will start sealing itself back up again. Right now, major events such as global warming and variations of temperature and wind are causing disruptions in the healing process of the ozone layer.

Eagles did not walk to Tasmania after all

The wedge-tailed eagle probably arrived in Tasmania much more recently than was previously thought.

The magnificent wedge-tailed eagle or 'wedgie'.

19,000 years ago much of the world was covered in ice. Most of the rain that fell on the land froze and because of this the sea level was about 120 metres lower than it is today. Back then, many places that are now islands were connected to continents by what we call 'land bridges'.

Until about 12,000 years ago you could walk from mainland Australia to Tasmania.

When the ice melted and the sea level rose, many animals and plants became trapped on these islands.

Why did Typhoon Haiyan cause so much destruction?

Typhoon Haiyan, one of the most powerful and destructive tropical cyclones ever seen, has devastated parts of the Philippines, destroying homes and killing thousands of people.

How did this happen?

Tropical cyclones - or typhoons, or hurricanes... they are all the same thing - form over the ocean when warm sea temperatures and an unstable atmosphere together build a large, rotating storm.

A radar image showing the wind speed of Typhoon Haiyan as it hit the Philippines. The red and pink parts are the most intense. Note the calm 'eye' of the storm. Source: Philippines Government

In the Philippines, a tropical cyclone gets called a typhoon when wind speeds are above 118 km/hr. Typhoon Haiyan had winds up to 325 km/hr! Scientists are still looking at all of the data that was collected during the typhoon, but they think that typhoon Haiyan was the fourth most powerful tropical cyclone that we know about, and the most powerful to reach the land.

Global warming, ocean cooling

The so-called 'pause' in global warming over the last 15 years might be explained by cooler ocean water sucking the heat out of the air.

CO₂ keeps on rising. Source: NOAA

We know that carbon dioxide (CO₂) causes heat to be trapped in the air and we know that CO₂ levels have been increasing over the last 150 years. So the air should just keep heating up, right? But the temperature has hardly risen since 1998. Why?

Is there less heat coming from the sun? Are there more clouds (which cause cooling)?

What is the deal, Earth?