Saturday, August 30, 2014

Proof of pollution in NASA images

For today's blog posting I decided to check in with NASA's webpage On the 10th anniversary of the launch of NASA's Aura spacecraft, the webpage offers ten examples of how the satellite has changed our view of dust, pollution, aerosols, and ozone in our atmosphere.

The photo above was taken by the satellite showing the atmosphere above southwestern Asia. Cold winter weather and burgeoning industrial economies have made for difficult breathing in Asia and the Middle East. News reports from Tehran, Beijing, and other cities have described hazy skies with very low visibility; restrictions on driving, factory operations, and outdoor activity; and hospitals full of people with lung ailments.

The map above shows the concentration of nitrogen dioxide in the atmosphere. Shades of orange reflect the relative abundance of the polluting gas. Nitrogen dioxide is a key emission from the burning of fossil fuels by cars, trucks, power plants, and factories; the combustion of fuel also produces sulfur dioxides and aerosol particles. When the weather is hot and sunlight strongest, nitrogen dioxide emissions usually lead to the creation of ground-level ozone. In the winter, the gas is less likely to breed ozone, but it does linger for a long time and contribute to fine particle pollution. Year-round, it is a good proxy for the presence of air pollution.

About a quarter-century ago, scientists and policymakers unveiled what the United Nations calls “the most successful treaty in UN history.” On September 16, 1987, the first 24 nations signed on to the Montreal Protocol on Substances that Deplete the Ozone Layer; 173 more have signed on in the years since. The international agreement likely saved the world from an environmental crisis, while setting an example for how to develop and implement environmental policy.

Prompted by scientific observations from the laboratory, the ground, aircraft, and satellites, the Montreal Protocol first reduced and then banned the chlorine- and bromine-based chemicals (particularly chlorofluorocarbons, or CFCs) that destroy atmospheric ozone. The destruction of the ozone layer allows more of the Sun’s ultraviolet radiation to reach the surface of the planet, increasing the risk of sunburns, skin cancer, and eye damage. The most prominent and infamous sign of depletion is the annual “ozone hole” that forms around the South Pole.

In 1979—when scientists were just coming to understand that atmospheric ozone could be depleted—the area of ozone depletion over Antarctica grew to 1.1 million square kilometers, with a minimum ozone concentration of 194 Dobson Units. In 1987, as the Montreal Protocol was being signed, the area of the hole reached 22.4 million square kilometers and ozone concentrations dropped to 109 DU. By 2006, the worst year for ozone depletion to date, the numbers were 29.6 million square kilometers and just 84 DU. By 2011, the most recent year with a complete data set, the hole stretched 26 million square kilometers and dropped to 95 DU. According to NASA scientist Pawan Bhartia, “The Antarctic hole is stabilizing and may be slowly recovering. Our focus now is to make sure that it is healing as expected.” The amount of ozone-depleting substances (ODS) in the atmosphere has stopped rising in recent years, and may actually be decreasing. 

In 1998, the U.S. Environmental Protection Agency (EPA) called on 22 eastern states to develop plans to significantly reduce emissions of nitrogen oxides, a group of highly reactive gases released by combustion engines, electric power plants, and a range of industrial activities. In 2005, the EPA issued the Clean Air Interstate Rule, a regulation that encouraged states to use a cap-and-trade system to further reduce emissions of these polluting gases.

About a decade later, the effects of these federal and state efforts have left the air far cleaner than it was before. Total nitrogen oxide emissions have fallen by 47 percent in the United States since the late 1990s. Emissions from electric power generation and highway vehicles, the two largest sources, have decreased by 68 percent and 43 percent respectively, according to EPA statistics. The declines are even large enough to be seen from space.  The measurements by NASA are depicted in the map above.  The larger the yellow circle, the larger the decrease in polluting gases.

Jesse Allen and Michael Carlowicz., using data provided courtesy of the Aura OMI science team.
Robert Simmon, using imagery from the Ozone Hole Watch. Caption by Mike Carlowicz.
Robert Simmon, using data from Duncan et al., 2013. Caption by Adam Voiland.

Thursday, August 28, 2014

Discovery of Deep Ocean Methane Seeps

I came across an article published by the BBC about the discovery of more than 500 new methane seeps off the U.S. east coast.  Previous to this discovery scientists only knew about a few of these seeps.  The link for the article is .

According to the article, "The team behind the new findings studied what is termed the continental margin, the region of the ocean floor that stands between the coast and the deep ocean. In an area between North Carolina and Massachusetts, they have now found at least 570 seeps at varying depths between 50m and 1,700m. Their findings came as a bit of a surprise."

The chart below is a sonar image of one of the new methane plumes discovered off the US east coast.

Since the seeping vents are located around 500m below the ocean's surface, scientists believe that the temperature and pressure allow the methane to reconstitute into a sludgy confection of ice and gas called methane hydrate, or clathrate.   A USGS picture of this methane sludge is shown below.

At this time it appears that the methane is not reaching the surface, but instead is dissolving into into seawater, combining with oxygen, and transforming into CO2.  Even though researchers estimate that there may be as many as 30,000 undiscovered methane vents worldwide, they do not think that any of this carbon dioxide is being released into the atmosphere -- yet.  However, they have estimated that these undersea sediments are one of the largest reservoirs on Earth and contains around 10 times more carbon than the current atmosphere.

Over geologic time the oceans could become saturated and eventually this carbon dioxide could begin reaching the atmosphere.  This is just another reason why our species as an inhabitant of this planet should limit our own carbon footprint.


Wednesday, August 27, 2014

Lake Superior August Beach -- Post 3

I didn't get to post photos to my blog early this morning since I had a family who hired me to teach the agate/rockhounding class.  One of the teenagers did well:  she found two agates!

While I have a few minutes in the museum between customers, I will try to post the remainder of the photos from the beach excursion I did the other night with Jamey and Lois Fite.

Looking east there is more beach, rock, and driftwood.

Looking west there is erosion and devastation.

In places there was a lot of black sand.  This is the sand that people are using to pan for gold.  They are finding flakes, but it takes a lot of panning to get any gold at all.

You had to be careful where you stepped since the waves have covered up some of the hollow pockets with sand.  These are definitely ankle breakers.

The large Lake Superior waves carve out the bottom of the dune bluff, and the top falls down making these escarpments.

In the bluff escarpments there are bands of rocks.

Tuesday, August 26, 2014

Lake Superior August Beach -- Post 2

Today I'll continue posting the pictures I took Sunday night while enjoying an outing with friends, Jamey and Lois Fite (owners of the Agate Cross B&B, located in Grand Marais).  This time Jamey was in charge of the food.  He decided that we would have good old fashion pork and beans with onions and hot dogs.

Hot dog cooking...

Instead of buns, we used lettuce....

The flies were not bothering us too much, but they were bothering the dogs.  Lois used a branch of leaves to protect their dog, Bear.


Monday, August 25, 2014

Lake Superior August Beach--Post 1

Twice this week I was able to spend some time on the beach.  The other day I had a surprise when an old friend tracked me down.  Sasha Roberts-Levi worked at the nursery school my kids attended in the early 1980s.  For a few years she also watched my kids when I had to jump on airplanes during my corporate days.  When she was in Marquette attending a conference the other day, she saw my agate book while in Snowbound Books.  She then gave me a call and visited for a day on her way back down state, where she is a school administrator.  It was awesome to catch up after 27 years!  I was also able to show her around our end of the Pictured Rocks National Lakeshore.  Thanks, Sasha, for a great reunion!

First we stopped by 12 Mile Beach and had a picnic dinner.

Next, the Hurricane River.

And, finally, the Log Slide.

Then last night I went on a beach hike and had a picnic dinner with friends, Jamey and Lois Fite.  We were glad to see that the beach has recovered a bit.  The sandy section is a little wider.

That is, except to the east of the beach we visited.

There is not as much driftwood as there was a few years ago, but still there are impressive logs and stumps.

Mink tracks on the beach.

The waves were rotating in at a weird angle.

The fall colors continue to build....