Friday, December 13, 2013

Temperature records for Christmas and New years Days in Australia


Capital city temperatures have varied considerably across all the capitals on Christmas Days in the past. Here is the list of the capital city hottest and coldest - all in terms of maximum temperatures

Hot Christmas days:
Adelaide: 42.1C in 1888 - the hot Christmas Day capital city record.
Perth: 42.0C in 1968
Melbourne: 40.7C in 1907
Brisbane: 39.2C in 1972
Sydney: 38.6C in 1868
Canberra: 37.1C in 1957
Darwin: 36.8C in 1892
Hobart: 36.0C in 2015

Cold Christmas days:
Hobart: 12.6C in 1984 - 
the cold Christmas Day capital city record.
Canberra: 14.5C in 1947 – snow in Alps of Victoria and NSW
Melbourne: 14.5C in 2006 – snow in Alps of Victoria and NSW
Adelaide: 17.4C in 1922
Sydney: 17.6C in 1962
Perth: 19.7 in 1945
Brisbane: 23.8C in 1909
Darwin: 24.6C in 1932

New Years Days show similar variation. Heres the equivalent list for the 1st January:

Hot New Years days:
Adelaide:  43.1C in 1900
Perth:  42.2C in 1997
Melbourne: 41.2C in 2008
Brisbane:  38.4 in 1903
Sydney: 44.2C in 2006 - the hot New Years Day capital city record.
Canberra: 39.9C in 2006 - same day as Sydney
Hobart:  40.6C in 1900 - same day as Adelaide
Darwin: 37.7C in 1896   

Cold New Years days:
Hobart:  14.1C in 1949
the cold New Years Day capital city record.
Canberra:  18.4C in 1956
Melbourne: 15.7 in 1949  
Adelaide:  17.4C in 1970
Sydney:  19.3C in 1871
Perth: 20.9C in 1907 - same year as record hottest Christmas Day in Melbourne
Brisbane: 23.7C in 1895
Darwin:  27.4C in 1997

1997 was an interesting New Years Day - the hottest temperature for Perth and the coolest for Darwin on the same day!

Thursday, November 28, 2013

Tornados in Australian Capital Cities


The tornado in the Sydney suburb of Hornsby earlier in November 2013 generated widespread discussion about tornados that we sometimes see in Australia. In fact we do see them quite often but happily not with the same frequency and intensity as those experienced in the United States.

It is a little known statistic that every capital city in Australia has experienced at least 1 tornado since the beginning of the 20th century and this list makes interesting reading.  


Adelaide:


On June 11th 1931 a violent tornado carved a path of destruction through North Adelaide. People were injured and several houses destroyed in the general area. In addition many trees were blown over and there were widespread power outages as wires were torn down in the maelstrom. After travelling several kilometres in a southeast direction the twister blew itself out just to the east of Adelaide Zoo.

Above: Some of the damage produced by the Adelaide tornado of 1931.

Sydney:
On March 27th 1906 a tornado blasted across North Sydney, producing widespread destruction across the area. One person was killed and more than 100 houses were seriously damaged or totally destroyed. From analysis of photographic evidence it seems likely that this was the most intense tornado ever recorded in the Sydney area.
  










Above: A newspaper account of the North Sydney tornado of 1906.

Melbourne:
On 2nd February 1918 two tornados moving across Port Phillip Bay struck the bayside suburb of Brighton, before moving inland. Two people were killed and numerous homes destroyed, with the estimated wind speeds generated around 250 km/hr.
  



Left: A local church destroyed by the tornado in Brighton on 2nd February 1918. (Image from Wikipedia Commons)

Hobart:
On November 9th 2012, three weak tornados were reported in the Hobart area. These were associated with an outbreak of severe thunderstorms over southeast Tasmania, with hail and heavy rain also occurring. Only localised damage was reported.

Brisbane:
On the 4th November 1973 a tornado blasted across the western and southern suburbs of Brisbane on a track over 50 km in length.  Rated as one of Australia’s most damaging twisters it produced severe damage with 500 houses unroofed and nearly 1400 badly damaged.

Canberra:
On Friday 17th December 1943 a tornado swept across the foot of Mount Ainslie, to the northeast of the city centre, uprooting hundreds of trees. Some minor damage was reported on the fringes of the twister, around Turner, Braddon and Ainslie. 


Left: Contemporary newspaper article describes the Canberra tornado.

Perth:
A severe thunderstorm with an accompanying tornado struck Perth at 8 am on Wednesday May 3 1905. A number of buildings in Murray and Hay streets were heavily damaged.

Darwin:
On Wednesday 8th April 1931 a tornado and waterspout struck Darwin, producing widespread damage to housing and infrastructure. Many trees were uprooted and telegraph wires were blown down for a considerable distance inland.

Without doubt this list will be added to in the future.

Sydney's rainfall, spring 2013

Sydney's spring of 2013 will be the wettest since 2004.

This year we've seen 267.8 mm fall during spring (up until 9 am on Thursday 28th November) and this is the highest total since the spring of 2004, when 361.0 mm fell.

The long term average for spring is 228.9 mm


Sunday, September 22, 2013

1964 Tokyo Olympics - Bob Hayes

One of the outstanding athletes of the Tokyo Olympics of 1964 was Robert Lee Hayes – nicknamed with considerable justification as “Bob the Bullet” because of his amazing feats as a sprinter.

Hayes was a strong and muscular man – around 1.8 m in height (5’11”) and tipping the scales at 84 kg (185 lb), with a bullocking running action that relied on sheer power rather than a classical style. But because of his great strength he was able to light up the track and accelerate away from the opposition in a stunning burst of speed. He was not a Formula 1 runner such as we saw later with the great Carl Lewis. Rather he was a V8 dragster, and the power plant he developed turned out to be one of the greatest in the history of track and field.


Bob "the Bullet" Hayes at speed. He relied on his great strength to generate record breaking times. (Image form Wikipedia Commons) 

Born in 1942, he hit the peak of his powers as an athlete just in time for the Olympic Games in Tokyo in 1964 where he became officially the worlds fastest human after winning the 100 metres in a world record time of 10.06 seconds. This was an amazing time taking into account the fact he was running on a cinder track (much slower than the modern synthetic surface) that had been chopped up by a previous race and also wearing borrowed shoes.

Footage of his fantastic run can be seen at

http://www.youtube.com/watch?v=PJ88Iq_GGjc

He really hit the world headlines with that win but a few events later, the men’s 4x100 metre relay, saw him cement his name into Olympic legend with one of the great runs of modern history.

The Tokyo Olympic Stadium in 1964 - scene of Bob Hayes' triumph. (Image form Wikipedia Commons)

Hayes was running the last leg for the United States and received the baton in a terrible position – some 4 to 5 metres behind the field. With only about 100 metres to run this would normally be a hopeless situation, but Hayes was not normal, even by Olympic standards. 

He was a slow starter off the blocks because he had a lot of machinery to move and it took a few paces to find his rhythm and balance. The running start of the relay suited him far better.

He blasted into action and hit top gear almost immediately and in the words of one press account “ exploded down the track in an eruption of speed never witnessed before or since”. He rocketed past the field in a little over 50 metres and was accelerating away from his nearest rival when he hit the tape in a new world record time of 39.0 seconds. It was an awesome display of power running that has never been duplicated in any Olympic games since.

A lot of conjecture has followed down the years about how good Hayes really was. It seems to be the consensus amongst experts that had he run on synthetic tracks with modern shoes and with electronic timing he would be right up there with the very best of today.

After he retired from athletics Bob Hayes joined the Dallas Cowboys as a wide receiver where his unstoppable speed forced opposition teams to change their entire defensive pattern. He became one of the all time great professional footballers and was inducted into the Hall of Fame in 2009. He is the only man to win both an Olympic Gold medal and a Super Bowl Ring.


Robert Lee Hayes passed away in 2002, following a bout of prostate cancer. He left behind a legacy that will never be forgotten in the world of sports.

Sunday, June 23, 2013

What Causes Climate Change?

With all the massive publicity given to the issue of climate change, in particular global warming, over the last decade, it's an important exercise to look at the possible causes of this, particularly as it now has assumed major international political dimensions.

We can talk about “temperature change” in close parallel with “climate change” as temperature is the main driver of our climate system. Changes in temperature patterns produce a large variety of “knock on” effects such as variations in rainfall, humidity, snow, cloud cover and wind regimes around the world.

We know from so called proxy data that global temperatures have varied considerably across the known history of the Earth, over periods of millions of years. Climatologists studying such data as ice cores, rock structure, lake sedimentation, glaciers, fossils and tree rings have been able to build up at least a rough picture of our past temperature patterns.

















From what we understand, the temperature time line of planet Earth looks something like this – where "mya" means “million years ago”. The reference line shown in red is the present global temperature and we see there are numerous instances where this line has been exceeded (warm epochs) and others when the reverse is the case, the times of Ice Ages.

The obvious question follows – what could be producing these variations?

In fact several likely causes have been identified, all of them entirely natural except one where climate scientists say there may be a human “footprint” – the so called anthropogenic effect.

This is a summary:

Milankovitch cycles: A sequence of “wobbles” of the Earths rotational axis and irregularities in its orbit around the Sun that occur over long periods and were first identified by the Serbian astronomer Milutin Milankovitch early in the 20th century. These cycles produce periods of warming and cooling in the Earth’s climate over time scales of several thousand years.

Serbian scientist Milutin Milankovitch - discoverer of the so - called Milankovitch cycles. (Image from Wikipedia commons)

Impact from extra terrestrial bodies: Large meteors and possibly even comets have collided with the Earth over past millions of years and these have strongly affected the climate. With a collision of this type a vast amount of debris is injected into the atmosphere and this can shield the surface of the Earth from solar radiation for extended periods, resulting in substantial cooling. It is suspected that one such collision around 65 mya produced a much cooler global climate for several thousand years, resulting in the demise of the dinosaurs.
A NASA impression of the giant collision of 65 mya that led to the extinction of the dinosaurs. (Image form Wikipedia Commons)

Continental drift: The world’s great continents actually move relative to each other at very slow rates of only a few millimetres a year. But over millions of years this movement becomes significant with different distributions of land and ocean resulting and changed patterns in ocean currents. These currents flowing around the world play a major role in transferring surface heat from tropical latitudes towards the polar regions and these have a major impact on climate patterns. The Gulf Stream, for example, produces much warmer weather for the United Kingdom and western areas of Scandinavia than areas of similar latitude in Canada. Disruption of these ocean currents, caused by continental drift, would certainly produce significant climate change.

Volcanoes: In a similar fashion to meteor impact, volcanic eruptions can inject massive amounts of dust into the atmosphere that result in solar shielding and global cooling. The 1815 eruption of Mount Tambora in Indonesia was a major cause of the so-called “Year without a summer” in 1816, when abnormally cold temperatures spreading across England and Europe produced widespread crop failures and famine.

The Mt. Pinatubo eruption in the Philippines, 1991. (Image from Wikipedia Commons)

Cosmic rays: These are high-energy particles that constantly bombard the Earth’s atmosphere. They are thought to originate from outside our solar system and could be produced by massive supernovae, or stellar explosions, from far distant stars. It has been speculated that the “gusts” and “lulls” in cosmic ray activity could produce climate change but this remains an area of controversy.

Variation in solar power: Observations in the power output of the Sun shows it to be variable with several known cycles. These include those of 11 years, 88 years, 208 years and 1000 years. There are probably more and these would have some type of impact on our temperature and climate system, although the specifics are far from clear

The Sun - power emitted varies over several different time scales (image from Wikipedia Commons)







Changing gas concentrations within the atmosphere: Our atmosphere contains a mixture of gases, with the so called “greenhouse gases “, including water vapour, carbon dioxide and methane, playing a major role. These gases prevent a total escape of solar energy back out into space and keep our global temperature warmer than it otherwise would be. Climatologists are worried that by the constant burning of fossil fuels we increase the concentration of carbon dioxide and thereby raise global temperatures. This mechanism for climate change, if real, is notably different to others in that it is produced by human activity rather than the natural processes already noted. This is known as the anthropogenic effect.
For information on how past climates have been measured go to:

Sunday, June 16, 2013

Bring Back National Service?

National Service has always been a highly contentious matter in Australia, particularly during the Vietnam War era when 20-year old conscripts were required to become combat soldiers in a real “shooting war”.

Ultimately some 63,000 young men were called up between 1965 and 1972 and 15,380 served in Vietnam. 184 National Servicemen died there and 880 were wounded in action.

Australian troops arrive at Saigon Airport 
during the Vietnam War - Wikipedia image

Towards the end of the war the opposition to sending conscripts to Vietnam had become very strong, with several large public demonstrations taking place in capital cities and organisations such as the “Save our Sons” group gaining considerable support.

The war had become generally unpopular by 1972, to such an extent that the then leader of the Opposition, Gough Whitlam, made the ending of conscription one of his key election issues. It certainly did play a significant part in producing a change of Government, and primarily for this reason successive political parties have steadfastly avoided any plans for the reintroduction of National Service.

The Hon. Gough Whitlam, 21st Prime Minister of Australia
(Wikipedia image)

But perhaps it was not National Service, as such, that was the basic problem, but more the way it was implemented. The selection system, involving the drawing of a marble from a Tattersall’s lottery barrel, provided a date and all 20 year old men whose birthday fell on that date were called up. The Leader of the Opposition in 1965, Arthur Calwell, described this system as the ‘lottery of death’.

Then there was the fact that conscripts were sent into a war zone. It’s bad enough when an Australian soldier is killed in an overseas war, but when a National Serviceman is killed in action, the situation becomes political dynamite.

But National Service does not have to be like this. There are ways of instituting a system that avoids these highly contentious issues and is still of considerable benefit to both the individual and to the nation.

Various schemes have been suggested over the years and here is one of these.

A call up for all twenty year olds is instituted – men and women – with the requirement for a three - month period of service. The inductee would have a choice of various electives and these could be chosen from the following areas:

The Army – a basic training course

Community work – Meals on Wheels, shopping and gardening for the elderly, work in nursing homes, Salvation Army, Vincent de Paul.

Council work – bushland regeneration

State Emergency Services (SES)

Rural Fire Services (RFS)

If Australia is involved in armed conflict at the time there would be no requirement for the conscript to become involved unless he or she volunteered and this would require leaving the National Service scheme and joining the regular Army.

“Points” could be attached to these activities depending on Government priorities, and
after a certain number was amassed, the conscript would be entitled to a subsidised home loan.

The SES in Victoria attend a vehicle accident
(Wikipedia image)

Such a scheme would be of considerable benefit to the nation. We would develop a large number of young people with basic military training that could be of great assistance in the event of mobilisation. Work in the SES and Rural Fire Services would improve our responses in emergency civil situations.

A considerable amount of useful community work would be undertaken – work which is presently in “on hold” because of the lack of people power.

And finally, such work would be of great benefit to the individual. Apart from the character building and discipline that comes from involvement in work of this type, unique networking opportunities arise from the mix of people that comes with National Service.

Would it work?


Ask not what your country can do for you – ask what you can do for your country - President John F. Kennedy, January 20th 1961.

Wednesday, June 12, 2013

Drunk in Parliament - Disorder in the House

In recent times allegations have flown regarding Members of the NSW Parliament being drunk in the House, and this has led to speculation about declining standards of behaviour amongst our leaders.

But we needn’t worry too much – the Parliamentarians of today are mostly model citizens compared to many of their 19th century counterparts.

Cyril Pearl in his “Wild Men of Sydney” described the NSW Parliamentary scene of the 1880’s as anything but an edifying spectacle.

NSW Parliament House, Macquarie Street, Sydney c 1895. (Charles Kerry Photograph)

“Violent behaviour and violent language were condoned or scarcely rebuked; fights between members were not uncommon and the sight of a drunken statesman falling off his bench during a debate excited amusement rather than indignation”.

The association between alcohol and legislation was a strong one and regarded as entirely normal. Pearl recounted that “…..a timid proposal that grog should be banned in the Parliamentary refreshment room was easily defeated”.

Sir John Robertson, Premier of NSW on five different occasions during the 19th Century, remarked that “None of the men who in this colony have left footprints behind them have been cold water men”. Sir John restored the financial affairs of the Reform Club, when as President, he advised the members that “We must drink the bloody club out of debt”.

Sir John Robertson, Premier of NSW, c 1880. (Image from Wikipedia Commons)

The newly elected Adolphus Taylor told his supporters in 1882 that “Mudgee is represented by three good drinking men – myself, Sir John Robertson and David Buchanan”.

But perhaps the most notorious drunkard in the House was John Norton, editor and owner of the “Truth” newspaper and Member for Sydney-Fitzroy in 1898. On one occasion, during Parliamentary debate, he was removed from the House for “shouting drunkenly, to Mr. J. C. Watson, “Damn and f..  you” , and on the last night of the session he was so drunk that he urinated on the floor of the Chamber. Pearl recorded that he was then “dragged out by two constables to the accompaniment of salvos of ripe oaths and the crash of broken glass…”



John Norton, Member for Fitzroy, c 1898.
(City of Sydney Archives, NSCA CRS 54/315

Such lamentable scenes now belong in the past and the average politician of today is a hard working and effective contributor to Australian society. Any lapses that may have occurred over the last few months would barely have raised an eyebrow in the Parliament of the late 19th Century. The election of women Members to the House has undoubtedly helped raise the standards of behaviour in this respect.

Thursday, May 23, 2013

The Oklahoma and Tri-State Tornados


The catastrophic tornado that descended on Moore, Oklahoma on May 20th 2013 was one of the most intense yet observed. Now officially rated as an EF 5 system, the highest on the tornado rating scale, it is believed to have generated surface winds of around 340 km/hr (210 mph).


The tornado as it moved to the southwest of Moore - image from Wikipedia Commons (click to enlarge)

The funnel was estimated to have been more than 2 km (1.3 miles) across and during its 50-minute life span travelled some 27 km (17 miles), including a rampage across the highly populated Moore area.

The tragic death toll is, at the time of writing, 24 and more than 200 people were injured.  The damage bill will run into billions of dollars.

Comparisons with the infamous Tri State tornado of March 18 1925 have already been made. In this event a twister ripped through some twenty sizeable townships, including Gorham, Murphysboro, De Soto, West Frankfort and Parrish, all in southern Illinois, causing utter destruction right across the area.

Eventually the tornado crossed the border into Indiana, where it inflicted massive damage to the townships of Griffin and Princeton, before finally abating, after the longest continuous rampage of any known twister.

Contemporary newspaper article following the Tri State tornado of 1925 - image from Wikipedia Commons (click to enlarge)

Subsequent investigation of the damage trail revealed a monstrous gouge of destruction across the countryside, some 353 km (219 miles) long and about 1.2 km (three quarters of a mile) wide. From existing photographic evidence of the damage produced, experts have rated the Tri State as an F5 tornado.

In all, 695 people died - still the record by far for an American tornado. Over 2000 were injured and some 15,000 homes demolished.

It is difficult, if not impossible, to directly compare these tragedies, but one statistic does stand out – the massive difference in the death toll. During the Tri State event there was no organised tornado warning system, no radar imagery and no satellite photographs available. This twister struck virtually without warning.

For the Oklahoma event, effective short-term warnings were issued by the US National Weather Service and these, without doubt, saved many lives. The great strides in public education about tornados, as conducted by the Weather Service and other Government agencies have also been most effective. And this, together with publically available information on the Internet, plus the training and skill of the National Weather Service meteorologists, helped prevent another Tri State scale death toll.

The logo of the National Weather Service of the United States - image from Wikipedia Commons (click to enlarge)

Unfortunately tornados are part of the climatology of the southern parts of the United States but improved forecasting skill, together with technology and public education is making a real difference. Our hearts go out to the people on Moore in Oklahoma who have been devastated by this event.

For an Australian example of the increased effectiveness of weather forecasting see:

Sunday, February 17, 2013

Meteorite Rocks Russia


On Friday 15th February 2013, locals in the Russian city of Chelyabinsk were astonished to see a blinding light streak across the sky in the early morning glow, with a brightness rivaling that of the sun itself. Soon after, amid noises of rolling thunder, the ground shook, buildings swayed and windows shattered. It turned out later that some 1200 people had been injured, mostly by falling debris and flying glass from damaged buildings.

Reconstructing this extraordinary event, scientists concluded that the event was generated by a meteoroid exploding above the ground, producing a giant shock wave that blasted downwards and outwards and generating energy similar to that of a small nuclear explosion.

Planet Earth is enshrouded by a protective blanket - the atmosphere – that enables life as we know it, in all its forms, to exist. But of equal importance it provides an invisible shield that protects us from the fusillade of rocks called meteoroids that constantly bombard us from outer space.

When a meteoroid enters the atmosphere, travelling at speeds normally in excess of 50,000 km per hour, it begins to burn up because of friction with the atmospheric gasses. This produces a bright streak of light across the sky that is normally only visible at night. If you are to go outside on a clear night and observe the sky for a period of half an hour or more you will usually see one or more of these luminous, transient streaks that usually only last for less than a second. This streak of light is known as a meteor.

A meteor in the night sky
(Image form Wikipedia Commons)

In most cases the chunk of rock will burn up or vaporize before reaching the ground, and it is this protective property of the atmosphere that has played a big part in the survival of life on the planet. Without it we would look like the Moon that has no such protection and is pockmarked with impacts from many thousands of meteoroids.

In some cases fragments will reach the surface of the Earth as a shower of rocks called meteorites and these are always interesting to scientists as they are ancient objects from the far flung reaches of outer space and often have a different structure and composition to rocks we find on Earth.

The surface of the Moon - scarred by countless meteoroid impacts.
(Image from Wikipedia Commons)

On rare occasions much larger meteoroids will enter the atmosphere, with a size big enough to prevent complete vaporization and these will reach the lower levels of the atmosphere partially intact and still travelling at tremendous speed. One of two things usually follows.

The first is what probably happened over Chelyabinsk – a massive mid air explosion that generates a blindingly bright flash, together with a shock wave and sound of rolling thunder. Smaller rock fragments will then shower across the area as meteorites. 

Russia was also the scene of another such event in 1908 when a monstrous air burst explosion over the Tunguska area produced a massive shock wave that flattened huge tracts of pine forest in the area, affecting a zone of around 2000 square kilometers. This was a much more powerful event that Chelyabinsk incident.

But what can also happen is when the rock remains largely intact all the way to the surface, eventually striking the ground with colossal force and producing a large impact crater. It has long been believed that an event such as this some 65 million years ago produced a cataclysmic explosion of such a scale that the atmosphere around the world was affected, with the extinction of the dinosaurs a consequence.

As a testament to this type of event, large impact craters can be found today, including “Meteor Crater” near Winslow, Arizona that was created about 50,000 years ago when a large meteorite slammed into the area. The crater is about 1.2 km across and 170 m deep.

Above: Meteor Crater, Arizona. (Image from Wikipedia Commons; Click to enlarge)

In Australia, Wolfe Creek is a large crater located in the desert of Western Australia about 150 km to the south of Halls Creek. It is estimated that this crater was produced by a meteorite that had a mass of some 50,000 tonnes striking the surface around 300,000 years ago. The crater is about 900 metres across and 60 metres deep.
Above: The Wolfe Creek Crater, Western Australia
(Image from Wikipedia Commons; click to enlarge)

What would happen if such an object were to stroke a modern city – such as Sydney or Melbourne? Well, the short answer is - disaster. The actual impact crater would take out a suburb, and the associated shock wave and impact vibrations would likely destroy much of the city. So should we be concerned?

Well the short answer to this is no. Events of such as Meteor Crater and Wolfe Creek probably only occur only about once every 50,000 years or so, and in the great majority of any future cases the actual impact point would be in non-urban area. You have more of a chance of being struck by lightning or kicked to death by a donkey that dying through meteorite impact.