Tuesday, December 13, 2011

Sydney: 100 million years ago - 100 million years in the future

The continent of Australia has undergone some significant changes in terms of geographic location in the past 100 million years and is expected to experience changes that are just as drastic 100 million years into the future. 100 million years ago, Sydney was located in the high latitudes in the southern hemisphere around 70 degrees south. The longitude during this time was around 75 degrees east. Consequently, this would cause snow and polar ice caps to be present most of the year, if not year round because of the limited sunlight the area would receive along with the extreme frigid temperatures during the long winter nights. Since it was located in the polar region, it would be dry and arid with a low sun angle and a high albedo, resulting in a significant cold reservoir. Sydney was still located on the east coast of Australia, so it had a maritime climate. Since Sydney was so high in latitude, the climate must have been much colder as it would have been dominated by the Continental Antarctic air mass along with the Maritime Polar. Sydney also would have been affected by the Polar High atmospheric circulation pattern, which produces little precipitation year round, which is much different than the current conditions of Sydney. Below is an image of the earth 100 million years ago and Sydney is indicated by the small red dot down by Antarctica.

The red dot in this photo represents where I believe Sydney was 100 million years ago
Click on the image to zoom in!
Image obtained from: http://www.cpgeosystems.com/mollglobe.html
100 million years from now, Sydney will move north and collide with Indonesia. Sydney will move right up to the equator and eventually into the northern hemisphere. I believe the future location of Sydney in 100 million years from now will be around 0 degrees north and around 170 degrees west. This will produce significant changes in the climate of Sydney resulting in more moisture from greater latent heat. Also, the sun's rays will hit the surface at a perpendicular angle, resulting in greater radiation. The albedo will be low because there will be a high absorption rate and greater conduction and convection that will take place. Instead of having winter in June and July and summer in December and January, Sydney will experience winter in December and January and summer in June and July. This means that most of its precipitation will come during the winter months of January and February instead of the summer months of June and July. In 100 million years from now when Sydney is on the equator, it will experience much more heat and precipitation than it currently experiences. The ITCZ will play an important role in the air circulation patterns, which will produce changes in the climate. The major air mass that will dominate the climate will be the Maritime Equatorial, which is a warm air mass. Sydney will still have a maritime climate since it will remain on the coast, but the water will be much warmer considering it is in the tropics.


The red dot in this photo is where I believe Sydney will be in 100 million years from now.
As you can see, it has moved north quite a bit and is now right on the equator.
Image obtained from: http://www.youtube.com/watch?v=pGACbD4zbWs
Click to see the animation from present day to 100 million years in the future

This is a climagraph showing present day precipitation and temperatures for Sydney, Australia
Image obtained from: www.weatherzone.com.au


This is a climagraph I generated showing the estimated average monthly precipitation
 and average daily temperature for Sydney 100 million years ago. I used the present day figures from
McMurdo Station, Antarctica because it is roughly in the same area and I think it would have
 had similar conditions as Sydney 100 million years ago.
Data obtained from: www.coolantarctica.com
This is a climagraph I generated showing the estimated average monthly precipitation 
and average daily temperature for Sydney 100 million years into the future. I used the present day figures from Tarawa, located at 1°28'N, 173°2'E, which is where I roughly expect Sydney to be in 100 million years.
Data obtained from: www.weatheronline.co.uk
There were several climate controls that affected Sydney 100 million years ago. Some macro-scale controls included the position of earth relative to the sun and the distribution of land and water on the surface. There were also some meso-scale climate controls that would have affected Sydney 100 million years ago including its proximity to the water since it was on the coast. Another affect would have been the atmospheric circulation patterns with the presence of the Polar High and the air mass dominance of the Continental Antarctic and the Maritime Polar.
Furthermore, I would expect there to be other climate controls that will be affecting Sydney 100 million years into the future. As far as macro-scale goes, the position of the earth relative to the sun will always play a factor along with the distribution of land and water on the surface. A meso-scale control would be its' location being close to the ocean. The Maritime Equatorial air mass will dominate the region and the seasonal fluctuations of the ITCZ will play a vital role in the future climate of Sydney. The Asian monsoon will come into play, which brings about a seasonal change in wind direction with the ITCZ being pulled northward in the northern Hemisphere summer due to the large land mass of the continent of Asia.
This picture shows the seasonal flucuations of the ITCZ.
100 million years from now, Sydney will be right in the middle of the ITCZ
Image obtained from: www.geology.um.maine.edu
In conclusion, I believe my climagraphs show an accurate portrayal of the potential climates 100 million years ago and 100 million years into the future. Due to the fact that Australia will be moving north rapidly, the average precipitation and the average temperatures will change dramatically along with the seasons. 100 million years ago, Sydney experienced average daily temperatures for July around -25 degrees Celsius. 100 million years from now, I expect that figure to rise to  around 29 degrees Celsius considering it is moving northward to the equator. Furthermore, sticking with July, precipitation will go from being around 17mm for the month of July 100 million years ago, to being around 160mm for July 100 million years from now. Clearly, Sydney has experienced some drastic climatic changes in the past coming from the frigid Antarctic and will experience even more into the future as it moves toward the warm equator.  

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