NOAA Teacher at Sea
Onboard NOAA Ship Ronald H. Brown
July 4 – 23, 2004
Mission: New England Air Quality Study (NEAQS)
Geographical Area: Northwest Atlantic Ocean
Date: July 14, 2004
Weather Data from the Bridge
Time 10:20 AM ET
Latitude- 42 22.77 N
Longitude- 70 52.02 W
Air Temperature 16 degrees C
Air Pressure 1004 Millibars
Wind Direction at surface Northeast
Wind Speed at surface 13 MPH
Cloud cover and type Stratus clouds and rainy
Why would anyone care if there are a few pieces of stuff 1000 times smaller than a grain of sand floating around in the air?
I visited one more piece of the elephant the past couple of days. To be more accurate, I have been visiting with some of the people who are studying another piece of the pollution elephant. I’ll call them the particle people. I have been visiting with Dave Covert, Tim Onasch, Tim Bates, Patricia Quinn, Theresa Miller, Kristen Schulz, Anders Petterson and Tahllee Baynard and Derek Coffman. These scientists are studying the particles that float in the air. Some particles are from human pollution and some are from natural sources. These chunks of stuff can be so small that it may take more than 250,000 lined up side by side to be an inch long, about 1000 times smaller than a grain of sand. Those are not even the smallest ones. Even though these particles are so tiny these scientists can find out what chemicals make up the particles and how many of the particles are in the air.
Amazingly, the scientists can sort out these very tiny chunks by weight. But as Paul Murphy told me the other day none of this is magic. A number of methods are used to sort the particles; here is the idea behind one of them. But you are going to have to use your imagination again. You are in a long narrow L-shaped hall. You look down the hall and at the end it makes a sharp turn to the left. You and a friend are going to have a race to the end of the L. But of course this isn’t a normal race. Each of you has an office chair in front of you. In your buddy’s chair is a very large person, your chair has a mouse. On your mark, get set, go!!! You both start pushing and running as fast as you can. One of the rules in our race is that you cannot slow down until you get to the end. Your friend is a major weight lifter and runner and so even though he is pushing a lot more weight the two of you are neck and neck, flying down the hall. Then you get to the sharp left hand turn. Remember this is a narrow hall and you can’t slow down. You and your mouse make the turn fine. Because of the heavy person in his chair your buddy can’t make the turn and hits the wall. You and the mouse end up at the end of the hall. Your buddy’s chair and passenger end up splattered against the wall.
But we were talking about microscopic particles in the air. The big white air inlet shown in pictures I sent yesterday pulls in air. Inside that large inlet are 21 smaller tubes which separate the air and sends it to different pieces of equipment. Some of the particles are removed from the air and are separated by size in a method similar to our race. A stream of the air, along with any particles that are in the air, quickly moves through a tube called an impacter. (In our race the mouse and person on the chair represent two different sized particles. You and your buddy are the air.) The air and any particles in the air have to make a sharp right hand turn. The largest particles can’t make the turn and they hit and stick to the “wall”. As the air moves through the tube, the air and remaining particles have to make progressively tighter turns. Each turn separates out a different sized particle. Those particles are collected off the wall and can be analyzed to determine what chemicals they are made of as well as weight and numbers of each size. Removing the particles from the impacter (the wall) needs to be done under controlled conditions so that contamination does not occur. Other techniques are then used to analyze the particles that are so small that they get through the “maze”.
While I have been on the ship there have been two main issues that I have been learning about. The first is learning about the techniques which the scientists use to study pollution. The second issue is: why make these observations and what will be done with them. Most of what I have described are the techniques that are being used. I have not written much about why the scientists are doing this and what they hope and expect to learn. More about that soon.
So why would anyone care about a few tiny particles anyway?
When the particles are breathed into a person’s lungs they can cause health problems. The particles may also have an impact on climate change, more about that in the next log.
Today the weather has again been cloudy, cool and rainy. The winds are blowing strong from the northeast which brings us clean air so we have moved south of the shipping lanes going into Boston to try and measure some ship exhaust. The swells are about 5 feet high and so the ship is rocking more than it has been. Everyone seems to be staggering about when they walk.
Questions of the Day
What are some of the main gasses which cause the greenhouse effect on Earth?
Where do the particles come from?
On average how long will they stay in the atmosphere?