Category Archives: atmospheric science

atmosphere, atmospheric science, chemistry, NASA

The Hole at the South Pole

Leave a comment

The Ozone Hole

Earth's ozone hole, from data provided by NASA's Goddard Space Flight center and the Ozone Hole Watch. The blue area is the 'ozone hole', where the density of the ozone layer is at its thinnest this time of year.

One of the best things that NASA does (along with other space agencies) is give us a look at our own planet — as a planet.  That is, the scientists who study our world do so in the same way they would study any other planet. They chart changes on the surface, map atmospheric activity, and chart all those changes over time.  For the past decades, scientists have charted something called the ozone hole, which forms over the south pole of our planet each year.  This image shows what the ozone looks like as of September 13, 2010, courtesy of the OzoneWatch website.

Satellite instruments monitor the ozone layer, and scientists use the data to create the images that indicate the amount of ozone in the upper atmosphere. The blue and purple colors are where there is the least ozone, and the greens, yellows, and reds are where there is more ozone.  The depth and size of this Antarctic ozone hole are affected by the temperature of the stratosphere (the upper part of Earth’s atmosphere) and the amount of sunlight that bathes the south polar region.

So, why is ozone such an important thing to monitor? This is a useful gas for the protection of life on this planet.  In the upper atmosphere, ozone acts to absorb ultraviolet-B emissions.  Such emissions, which come primarily from the Sun, can harm living systems. It’s safe to say that, without the ozone layer in our upper atmosphere, life on Earth would be severely harmed.  In fact, without the ozone layer, it’s possible that life wouldn’t have formed on this planet.  So, losing a chunk of our ozone layer each year is a big deal.  Scientists want  understand why this happens.

Now the good news is that the ozone layer is not thinning anymore — after more than half a century of actively thinning.  This is due to a ban on harmful chemicals that have damaged the ozone  layer.

We know that ozone is destroyed by chlorine- and bromine-containing chemical compounds.  We know that some aircraft emissions hurt the ozone layer.  We know a lot of different reasons why our ozone layer is under attack, not just from the Sun, but from below by the sentient life forms that inhabit the planet.

Sure, there are naturally occurring attacks on the ozone, but the largest attack comes from human activity. We use huge amounts of chemical compounds in industrial and home-based products. You may have heard of what’s referred to as chlorofluorocarbons. They escape to the atmosphere from refrigeration and propellants.  They persist for years in the lower part of the atmosphere, and eventually some migrate to the upper atmosphere. It’s a long-term process because the destruction of ozone doesn’t happen the minute CFCs get into the atmosphere.  But, it does eventually happen. So, even though we HAVE reduced our use of these compounds — the damage from the reservoir of ozone-destroying atoms and molecules has continued.  The damage that now shows up in the ozone hole probably comes from materials released well into the last century. With luck, and the continued ban on these chemicals, the ozone should get back to its 1980 levels by mid-21st century.

I know that there are still people who deny such problems existed — generally they are people who don’t want to believe that humans can have a deleterious effect on our planet’s ecosystems. The problems won’t go away because some people bury their heads in the sand. Oh, sure, their faces won’t get sunburned by the UV-B, but their hineys will.

So, what’s the effect of the loss ozone? Ask the people who live under that hole and who are at higher risk for cancer and other conditions that are caused or exacerbated by exposure to ultraviolet-B.  I was in South America a few years ago, at the very tip of the continent. The people who live there know first-hand what it’s like to live under a thinning ozone layer.  Sunblock is a constant friend.  Children are warned NOT to go out with out adequate clothing and sunblock.  If you want to know what life would be like on this planet with a thinner (or nearly nonexistent) ozone layer, talk to the children of Patagonia.

And, thanks to NASA and other agencies who continually monitor our planet from space (another fine example of how space exploration benefits us here at home), we might be able to learn enough to avoid dissipating our ozone layer more than it already is.

atmosphere, atmospheric science, climate change, Earth science, NASA, terra satellite

The Ash from a Distant Mountain

2 Comments

Watching the Fires from Space

The Southern California Fires as seen by NASA's Earth Observing System Terra satellite. Courtesy NASA. Click to embiggen.

Up here in the Rockies we’re seeing the effects of the Station Fire near Pasadena in a most dramatic way — ash in the air, blood-red sunsets and a red Moon. There’s so much ash floating around that our mountains in the distance look like one of those Japanese watercolor paintings with mist-shrouded hills.

But, far from being mist, this stuff is the particulate matter distributed from the fires consuming more than 100,000 acres (and growing) of brush, trees, and homes.  Overnight the historic (and very busy) Mt. Wilson Observatory was threatened by the fire, but thanks to the efforts of fire crews, the observatory is (so far) spared from the flames. (Note: the link goes to Mt. Wilson’s webcam which may or may not be operating.  For more info about Mt. Wilson itself, go here.)

I find it fascinating to look at the satellite images of this fire — or any fire in any region on our planet.  As time goes by, you’ll see more of these images, with the smoke plumes heading out and affecting other areas.  What happens in one place on our planet inevitably affects other places.  This is why NASA and other space agencies are launching mission after mission to study our home world — to understand the processes it experiences and how all the various systems of our planet are linked together.  Often, as with the fires in SoCal, understanding and studying these topics is a matter of life and death.