Aurora activty and ozone loss

By: Dr. Jeff Masters , 6:13 PM GMT on May 16, 2005

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The sun is only a year or so from the minimum of its 11-year sunspot cycle. This means few solar storms and not many solar charged particles hitting Earth's upper atmosphere triggering auroras. However, the sun has shown an unusual amount of activity the past 2 years, and last night both hemispheres were again treated to spectacular aurora displays (see the great aurora borealis and aurora australialis photos below!)

In a recent discovery published in March 2005 in Geophysical Research Letters, scientists reported that the high-energy particles that trigger auroras can also cause significant destruction of our protective ozone layer. Normally, ozone destruction is associated with human-emitted Chlorofluorocarbons (CFCs) in the lower stratosphere. However, the new discovery shows that natural processes can cause significant ozone destruction in the upper stratosphere.

"The 2003-2004 Arctic winter was unique," said Dr. Gloria Manney, a JPL atmospheric scientist and one of the paper's co-authors. "First, the stratospheric polar vortex, a massive low-pressure system that confines air over the Arctic, broke down in a major stratospheric warming that lasted from January to February 2004. Such midwinter warmings typically last only a few days to a week. Then, in February and March 2004, winds in the upper stratospheric polar vortex sped up to their strongest levels on record. The vortex allowed the nitrogen gases, which are believed to have formed at least 10 kilometers (6 miles) above the stratosphere as a result of chemical reactions triggered by energetic solar particles, to descend more easily than normal into the stratosphere."

What does all this mean in terms of the amount of skin-damaging UV radiation hitting the surface? Should you put on extra sunscreen the day after seeing an aurora? No, the time to put on extra sunscreen is when the polar vortex breaks up in the Spring, when ozone-poor air that was created by CFCs and the energetic solar particles bombarding the upper stratosphere finally gets mixed down to the mid-latitudes where most of us live. This has already happened this year, back in March and April. In another blog entry later this week, I will discuss the record ozone loss--up to 30%--that was seen in the Northern Hemisphere this Spring when the polar vortex broke down. I'll answer the question, "why are we seeing record ozone losses when we've already phased out CFCs?"

Aurora and Scorpius (astrophotographer)
this one has Scorpius in it for a bit of a variation!! This aurora was so wide it covered from the SE to the NW 180 degrees and over the zenith in elevation. Most of the images were taken at ISO 1600 and 30 second exposure
Aurora and Scorpius
Aurora 05-15 #2 (madmikee)
Same as #1
Aurora 05-15 #2

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4. kritikal
11:58 AM GMT on May 19, 2005
We did. Mars wasn't just fitting our fancy so we came here.
Member Since: July 8, 2003 Posts: 34 Comments: 15
3. fluffybunny
2:34 AM GMT on May 19, 2005
you humans worry too much about such little things. if you don't like your planet, go find another one...it's not that hard.
2. HAARP
8:13 PM GMT on May 17, 2005
If we are near the solar minimum and are temperatures are still rising than what will happen in the next 12 years as we near the solar maximum?

Does the fact that our magnetic field is weakening have anything to do with the solar minimum or our ozone loss?

We also had some major solar flares in this march I think I recall...maybe that had to do with the loss of ozone ?
Member Since: November 1, 2004 Posts: 42 Comments: 482
1. kritikal
6:18 PM GMT on May 17, 2005
One of the reasons for the unusual break down, IMHO, was due to the repeated barrage of solar protons caused by the very powerful solar flares of October/November 2003. These solar flares were the largest ever recorded, and while they may seem out of place as we near the solar minimum, statistics show that despite the 11-year cycle of the Sun's poles, the number of X-Class, or strongest, solar flares remain the same.

Below is the latest estimated auroral activity provided by NASA POES. You can check out the site for more info at http://www.sec.noaa.gov/pmap/.

Member Since: July 8, 2003 Posts: 34 Comments: 15

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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