The things you learn...
Sep. 9th, 2004 06:39 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
gemfyreHad an eye opener of a lecture this morning. Meteorology always interests me because of it's long ranging implications. You do something here and it's likely to affect somewhere far far away. Some people call this the "chaos" or "butterfly" effect but I call it reality.
There is moniotoring station on Tasmania's north-western corner. It was built here due to its isolation and relatively clean air. Not long after being built this station registered polluted air. The pollution had originated in Melbourne. Yep, the crap in the air had travelled to the pristine wilderness of Tasmania.
But that's not all. A while later it registered more pollution emanating from the west. It was pollution from the Kwinana industrial area south of Perth.
Makes you sick just thinking about it. A few places in the world pump crap into the air in huge amounts, and it affects EVERYWHERE and every living organism.
The second thing was to do with the "Bunny Fence" research. The Bunny Fence is Rabbit Proof Fence No. 1, a fence that runs all the way from near Ravensthorpe to just south of Port Hedland, a distance of almost 2000km. It was built to keep rabbits from migrating west onto the wheatbelt. Two other fences were built after it to stem the flow of rabbits. All failed, only fence No. 1 is still maintained. In the south it nicely delineates the wheatbelt from natural vegetation further east.
A few facts before I go on with this story.
- The atmosphere is not heated by the sun. The Earth is heated by the sun and any radiated heat warms the atmosphere.
- When land is cleared for crops its colour is lighter. Light colours reflect heat whereas dark colours (as native vegetation is) absorb heat.
- Uneven vegetation (i.e. native) helps to cause turbulence in the air flowing over it. Uniform wheat fields do not produce this turbulence.
- If there is moisture in the air, there needs to be cold and turbulence to cause clouds, and subsequently rain to form.
Over the past few decades a decrease in rainfall has been noted in the Perth and wheatbelt regions (hence the water restrictions - duh). But around Kalgoorlie and the goldfields the rainfall has increased. Where there are wheatfields, the air overhead is warm with reflected heat. Clouds fail to form and rainfall drops. Over the native vegetation, where the air is cooler (due to the heat being absorbed into the earth) and the turbulence is greater, clouds form and rain falls.
We were shown satellite images showing the sharp difference between the wheatfields and native vegetation. You can see the line of this fence easily from space.
Still, it all sounds kinda unreal. A theory those crackpot meteorologists give the governments to try and stop them from clearing the land to make MONEY even though it's quite clear the rainfall is dropping.
We were then shown a photo taken from a plane over the fence. There are low clouds on the native vegetation side and clear skies over the cultivated fields. The clouds are just as well delineated as the vegetation. THAT is real, there is no way you can say it's "just a theory" after seeing a photo like that. We've cleared a great tract of land to cultivate crops for food and mainly money and now the crops are faltering because we've severly affected rainfall patterns. It is real.
I also learned that Typha orientalis (Bullrush) grows about 2cm in a little over an hour. You could sit and watch the stuff grow. The problem is, around here it's a weed and near on impossible to get rid of.
There is moniotoring station on Tasmania's north-western corner. It was built here due to its isolation and relatively clean air. Not long after being built this station registered polluted air. The pollution had originated in Melbourne. Yep, the crap in the air had travelled to the pristine wilderness of Tasmania.
But that's not all. A while later it registered more pollution emanating from the west. It was pollution from the Kwinana industrial area south of Perth.
Makes you sick just thinking about it. A few places in the world pump crap into the air in huge amounts, and it affects EVERYWHERE and every living organism.
The second thing was to do with the "Bunny Fence" research. The Bunny Fence is Rabbit Proof Fence No. 1, a fence that runs all the way from near Ravensthorpe to just south of Port Hedland, a distance of almost 2000km. It was built to keep rabbits from migrating west onto the wheatbelt. Two other fences were built after it to stem the flow of rabbits. All failed, only fence No. 1 is still maintained. In the south it nicely delineates the wheatbelt from natural vegetation further east.
A few facts before I go on with this story.
- The atmosphere is not heated by the sun. The Earth is heated by the sun and any radiated heat warms the atmosphere.
- When land is cleared for crops its colour is lighter. Light colours reflect heat whereas dark colours (as native vegetation is) absorb heat.
- Uneven vegetation (i.e. native) helps to cause turbulence in the air flowing over it. Uniform wheat fields do not produce this turbulence.
- If there is moisture in the air, there needs to be cold and turbulence to cause clouds, and subsequently rain to form.
Over the past few decades a decrease in rainfall has been noted in the Perth and wheatbelt regions (hence the water restrictions - duh). But around Kalgoorlie and the goldfields the rainfall has increased. Where there are wheatfields, the air overhead is warm with reflected heat. Clouds fail to form and rainfall drops. Over the native vegetation, where the air is cooler (due to the heat being absorbed into the earth) and the turbulence is greater, clouds form and rain falls.
We were shown satellite images showing the sharp difference between the wheatfields and native vegetation. You can see the line of this fence easily from space.
Still, it all sounds kinda unreal. A theory those crackpot meteorologists give the governments to try and stop them from clearing the land to make MONEY even though it's quite clear the rainfall is dropping.
We were then shown a photo taken from a plane over the fence. There are low clouds on the native vegetation side and clear skies over the cultivated fields. The clouds are just as well delineated as the vegetation. THAT is real, there is no way you can say it's "just a theory" after seeing a photo like that. We've cleared a great tract of land to cultivate crops for food and mainly money and now the crops are faltering because we've severly affected rainfall patterns. It is real.
I also learned that Typha orientalis (Bullrush) grows about 2cm in a little over an hour. You could sit and watch the stuff grow. The problem is, around here it's a weed and near on impossible to get rid of.
