| Subject: You DO understand average temperature, don't you? |
Author:
sci guy
|
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Date Posted: 22:46:02 11/25/06 Sat
In reply to:
Curmudgeon
's message, "PS. Not all agree." on 16:44:21 11/25/06 Sat
Try reading the WHOLE article you link to...
(did youeven BOTHER to read teh headline?)
The changes wrought by Pinatubo's sulfuric acid cloud, which blocked a large percentage of sunlight from reaching the earth, initially included cooler summers and warmer winters, an overall net cooling at the earth's surface and altered winds and weather patterns, Robock said.
Yeah, slightly warmer in winter, a lot colder in summer. Net result? Cooling.
sheesh... are YOU ever THICK!
>"Although overall the planet cools after volcanic
>eruptions, over Northern Hemisphere continents it
>actually gets warmer in the winter. This is because
>the wind patterns change in response to heating of the
>stratosphere by the volcanic aerosols."
>
>
>href="http://earthobservatory.nasa.gov/Newsroom/MediaAl
>erts/2002/200202157818.html">http://earthobservatory.na
>sa.gov/Newsroom/MediaAlerts/2002/200202157818.html
>
>
>
>
>
>
>>You DO realize that th article says that volcanoes
>>COOL the earth, don't you?
>>
>>
>>>Can I get mhy donation back?
>>>
>>>
>>>
>>>>just when we thought we had the weather predictions
>>>>down. a new kink comes in to play. now we have space
>>>>weather, volcanic weather, fire weather, land mass
>>>>change weather.
>>>>
>>>>Volcanic eruptions on Iceland generated a cascade of
>>>>events that led to record low levels of water in the
>>>>Nile River in Africa and brought famine to the
>region
>>>>more than two centuries ago, a new study concludes.
>>>>
>>>>
>>>>
>>>>The findings will inform climate forecasting related
>>>>to future volcanic activity.
>>>>
>>>>
>>>>
>>>>From June 1783 through February 1784, a series of 10
>>>>eruptions from the Laki Craters on this European
>>>>island in the North Atlantic changed atmospheric
>>>>conditions in most of the Northern Hemisphere.
>>>>
>>>>
>>>>
>>>>Unusual temperature and precipitation patterns
>peaked
>>>>in the summer of 1783, causing below normal rainfall
>>>>in most of the Nile drainage basin and therefore
>>>>record low levels in the mighty river for up to one
>>>>year following the eruptions.
>>>>
>>>>
>>>>
>>>>When volcanic eruptions occur, large amounts of
>>sulfur
>>>>dioxide are released into the atmosphere. When this
>>>>gas combines with water vapor, aerosol particles
>>form.
>>>>These particles reflect sunlight back to space and
>>>>therefore cool average temperatures on Earth.
>>>>
>>>>
>>>>
>>>>Researchers used computer models to simulate how
>>>>Iceland’s Laki eruptions affected temperature and
>>>>rainfall levels over the stretch of land from the
>>>>Atlantic ocean to the “horn of Africa,” known as the
>>>>Sahel.
>>>>
>>>>
>>>>
>>>>Simulations showed that the aerosols formed by the
>>>>eruptions cooled average temperatures in the
>Northern
>>>>Hemisphere by up to 5.4 degrees Fahrenheit. Tree
>ring
>>>>data in Alaska and Siberia also showed reduced
>growth
>>>>during the same summer, signifying cooler than
>normal
>>>>weather.
>>>>
>>>>
>>>>
>>>>The abnormally cool temperatures reduced the
>>>>temperature difference between the land masses of
>>>>Africa and Eurasia and their respective water
>masses,
>>>>the Atlantic and Indian oceans. Typically, a sharp
>>>>contrast in temperature between land and sea drives
>>>>roaring monsoon winds. Monsoons are seasonal shifts
>>in
>>>>wind direction that signify the beginning of the
>>rainy
>>>>season.
>>>>
>>>>
>>>>
>>>>The lack of monsoons led to a reduction in cloud
>>cover
>>>>over the Sahel of Africa, southern Arabian Peninsula
>>>>and India that summer. This caused temperatures to
>>>>increase by as much as 3.6 degrees Fahrenheit and
>>>>induced drought in the region. The resulting food
>>>>shortage reduced the population of the Nile Valley
>by
>>>>a sixth.
>>>>
>>>>
>>>>
>>>>"Some of the driest weather occurred over the Nile
>>and
>>>>Niger River watersheds," said lead author Luke Oman,
>>a
>>>>researcher from Rutgers University, NJ. "The
>relative
>>>>lack of cloud cover and increased temperature likely
>>>>amplified evaporation, further lessening water
>>>>available for run-off."
>>>>
>>>>
>>>>
>>>>This dry weather corresponded with record low river
>>>>water levels from 1783 to 1784.
>>>>
>>>>
>>>>
>>>>“These findings may help us improve our predictions
>>of
>>>>climate response following the next strong
>>>>high-latitude eruption, specifically concerning
>>>>changes in temperature and precipitation," Oman
>said.
>>>>"Many societies are very dependent on seasonal
>>>>precipitation for their livelihoods, and these
>>>>predictions may ultimately allow communities time to
>>>>plan for consequences, including impacts on regional
>>>>food and water supplies."
>>>>
>>>>
>>>>href="http://www.livescience.com/environment/061121_
>e
>>r
>>>u
>>>>ptions_nile.html">http://www.livescience.com/environ
>m
>>e
>>>n
>>>>t/061121_eruptions_nile.html
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