Author Topic: Reasons for colder than normal Southern Hemisphere winter 2007  (Read 8248 times)

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Offline Harley Pearman

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Dear all

Now that I have a home computer, I can now respond again from home. I recently returned from the USA after a holiday.

Since returning I have noticed a sharply colder winter than normal and a succession of these winter fronts delivering snows and colder than normal conditions. The winter fronts have been stronger. I am fully aware of what is going on. It is also occurring in New Zealand too and Argentina where snow fell first time in 100 years in the capital.

Last week I hypothesised why this winter was colder than normal and why the snows. I suspect that a volcanic eruption in Ecuador could be the culprit. Called Tungaruah. The 5,023 metre high volcano blasted out a significant volume of dust and ash including sulphur dioxide emissions that skyrocketed during the November 17 Eruption. Looking at the eruptive history of this and the July eruptions 2006, sulphur dioxide emissions skyrocketed and the ash plumes reached 16 km high. Sulphur dioxide is a cooling agent and once it reaches a certain height, it thins out and goes around the hemisphere that the volcano is in. Tunguruah is in the southern hemisphere. The cold conditions are being experienced across this hemisphere.

It could well be the sulphur dioxide emissions blasted out. At 16 km it would thin out and create a thin veil around the southern hemisphere albeit briefly thus interfering with the weather briefly. The impact is more marked in winter.

The Dust Veil Index describes this. A slight cooling effect occurs after a big eruption above a certain VEI Figure. It  happened in 1992 after Pinatubo erupted in June 1991 and there is always a delayed effect.

The result is a colder than normal winter. I am seeing temperatures 1C to 2C colder than what they should be. Fronts have been stronger and there is unusual snows.  The last front continued the pattern and we saw snows across the Central Tablelands.

This has occurred over 3 land masses in the southern hemisphere that I am aware of. There could well be a link to what happened on 17 November 2006 and what we are seeing now. I would love any feedback because this is a scientific explanation that has occurred in the recent past but not detected until the effects are over.

Regards

Harley Pearman