September 18, 2011

Jet Stream Split Omega Blocking


 Again I don't understand why this is not mainstream news.  Peace

Fires and Floods From Same Phenomenon

By Tim Wall | Fri Sep 2, 2011 12:23 PM ET
August_2010_wildfire_in_Russia
Fires and floods were spawned by the same atmospheric event in 2010.
Last year, massive wildfires toasted the taiga in Russia while floods swept away lives and livelihoods in Pakistan. Though separated by 1,500 miles (2,414 km) and of opposite natures, the two disasters were linked by an abnormal change in the currents of atmosphere, called Rossby waves.
NASA researchers used satellite imagery of the air currents over Asia to identify a blockage, known as an Omega blocking event, that slowed the Rossby waves and split the jet stream over Russia. The blockage developed over a high pressure system above Russia.
Russia pakistanIt was as if a large rock (the Omega blockage) had fallen into a creek (the Rossby wave) and caused the current to split in two.
Normally hot, dry, high pressure systems pass over the area in a few days, but in this case the split jet stream could no longer push the hot, dry air out. For weeks, heat built up over Western Russia and the forests dried out. Eventually, fires broke out and consumed the dry trees.

NEWS: Russia Forest Fires Burn; Heat Wave Ongoing
At the same time, further west and downstream in the Rossby wave, a low pressure system formed in response to the high pressure system above Russia.
"From NASA satellite data and wind analysis, we can clearly see the connection between the two events," said William Lau, an atmospheric scientist at NASA’s Goddard Space Flight Center in a press release.
"Think of the atmosphere like a loose membrane. If you push one part up, something else has to come down somewhere else. If you produce a high in one region, you produce a corresponding low in another," Lau said.
Pakistan_flood_damage_2010 The low pressure system sucked cold, dry Siberian air into lower latitudes. This cold Siberian air smashed into warm, moist air flowing north from the Bay of Bengal. The collision occurred above Pakistan and caused monsoon rains to drop before they normally do.
In a normal monsoon year, the rains pass north over India from the sea, and drop in heavy torrents over Northwest India and parts of Pakistan as the warm moist air hits cool air from the Himalayas. Northern Pakistan wasn't prepared to receive the brunt of the deluge caused by the abnormal atmospheric event over Russia.
Though the NASA satellites were able to reveal what happened and the connections between the two disasters, researchers still don't know why the blockage occurred in the first place. The study also raises questions about how earth, wind and fire may have interacted to make the phenomenon worse.
BIG PIC: Disease Outbreak Feared in Pakistan Flooding
The Russian drought itself may have reduced rainfall since there was no water evaporating from the soil to form clouds. When the fires broke out, Lau suggests that dark particulates in the the smoke, called black carbon, may have worked to further shrivel cloud cover and increase the intensity of the drought.
The NASA study was recently published in the journal Hydrometeorology, and was authored by Lau and Kyu-Myong Kim, another NASA scientist.
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IMAGE 1: Russian wildfires in August 2010. (Wikimedia Commons)
IMAGE 2: This map shows temperature anomalies from July 20—27, 2010, compared to temperatures for the same dates from 2000 to 2008. The anomalies are based on land surface temperatures observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Areas with above-average temperatures appear in red and orange, and areas with below-average temperatures appear in shades of blue. Oceans and lakes appear in gray. (NASA/Earth Observatory)
IMAGE 3: Flood waters have washed away all ground means to reach the people stranded in the northern areas of the Swat valley in Pakistan, Aug. 11, 2010. (Wikimedia Commons)

7 comments:

  1. Living between a river and a creek, this sort of article makes me shiver. Especially in the fall, with lots of unknowns for the winter, and with the knowledge that everyone gets a share of good times and bad.

    Our weird weather this year gave us a cool summer, only 4 days over 100. Lots of backyard gardeners have had no tomatoes, though the ones in the fields around my house did fine. As a good thing, the green beans, beets, and snow peas produced abundantly and are still going strong. I'm talking about the field crops, I only grow flowers because I'm surrounded by such a bounty and we're all invited to share.

    I'm so delighted to see you writing again. XOX

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  2. Thanks for taking the time to share Jan. Seems we are all in the same boat . . . gets one to thinking - peace
    xox back atcha

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  3. You are correct, this should be big news.

    These jet stream blocking events can result in unprecedented hurricanes reaching Greenland (Igor et al 2010) and uncommon arctic air masses descending into Florida killing manatees and iguanas (Last 2 years running).

    Problem is... that it would mean that something other than global CO2 levels may be driving climate.

    And that would be politically unacceptable.

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  4. Dear Anonymous any other info on the wacky weather we have been having? what do you forsee? peace

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  5. My thought about all the wacky jet streams is along the lines of the deforestation of the rain forest along the equator. No one ever mentions how that might be a factor. Probably not PC

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  6. Wrecking bits everywhere, fixing bits everywhere too. Thank God. Peace

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  7. ...and man thinks he is in control! Funny!

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