Blowin in the Wind

During the past week, it has become evident that PM2.5 concentrations are significantly influenced by local meteorological conditions. This isn't a very ingenious comment, considering EVERYTHING suspended in the atmosphere is influenced by meteorological conditions. With this in mind, I guess it's still neat to prove that everything is right with the world and science is still behaving as it should.

So, lets provide example number 1. Late last week, after my return from Gulfport, I noticed these two distinct spikes in PM2.5 concentrations that occurred overnight (Figure 1).


Figure 1: PM2.5 concentrations

These brief increases are almost a full order of magnitude greater than the expected trend set earlier in the day. Clearly, a plume of something was advected (meteorology lingo for blown with the wind) over the instrument causing the higher readings. Had this been a poisonous gas (such as chlorine) the impacts on human life would have been huge. This plume, however, is still something that I would not want to be breathing in. Taking a look at wind data from this time, it is clear that a wind shift played a signifcant role in these higher readings. Figure 2 shows recorded 10 meter wind directions during this time.


Figure 2: Wind direction

At approximately 23:00, the wind changed direction from 50 degrees (from the NE) to 250 degrees (from the WSW). This change in wind direction lines up perfectly with the increased PM2.5 concentrations. This simple example provides clear evidence that small, microscale changes in the environment can produce significant changes in atmospheric pollutants.

The previous example was from a calm night, so your next question should be: What happens during an extremly unstable period, such as during the passage of a thunderstorm? No worries, I have diligently analyzed that situation also!

On the afternoon of June 28th, multiple thunderstorms passed through the area and provided some interesting data. Figure 3 below shows the changes in temperature and wind speed as the thunderstorms moved by.



Figure 3: Temperature and Wind Speed during the passage of thunderstorms.

The thunderstorm passages can be clearly seen when looking at the temperature data because of the sudden drops. When thunderstorms pass, they are accompanied by a pool of cold air that is immediately felt at the onset. Of course, wind speed is bound to increase during the thunderstorm, and this is also evident in the above figure.

So, what do you think the PM2.5 concentrations looked like during this time? The answer lies below!



Clearly, during the two main thunderstorm passages (at 13:30 and 17:30) PM concentrations fell dramatically. Thunderstorms get their energy by sucking air from the entire boundary layer (the lowest kilometer of the atmosphere) and using this air as fuel. Therefore, any pollutants at the surface are immediately taken into the thunderstorm and advected elsewhere/dissolved in precipiation.

TA DA!

The amazing effects of local weather conditions on the dispersion/advection of atmospheric particles!

In the wise words of Bob Dylan, "The answer, my friend, is blowin in the wind."

Oh Simpsons...How Right you Were!

If you have a spare twenty minutes to sit down and watch this Simpsons episode, I urge you to do so. Trust me, you won't be disappointed. The episode deals with Bart's trip to Knoxville TN, and Oak Ridge even makes an appearance.

When you click play, an add will pop up on another tab. Simply close this tab, come back to the blog page and click play again. And the episode should load.

Enjoy!

Goodbye Biloxi

After two weeks in Biloxi, we finally finished the project and headed home to Oak Ridge late last night. We ended up staying over in Birmingham (almost the half way point of the trip) and left early this morning finally arriving in Oak Ridge a little after noon.

Over the past week, I have failed to keep up with this blog simply because of the boring nature of the work. Since I promised to show the oh so exciting nature of balloon launches, here it goes.



The balloon is inflated with helium and is automatically shut off when the balloon acquires a certain buoyancy. We then tie the balloon. We then tie the tied balloon to the instrument package (called a radiosonde). We then let go of the balloon. We watch the balloon. We sit and wait for the next launch in another 1 hour and 45 minutes.

I know...exciting stuff.

Although the field work may be boring, the data is extremely interesting to a meteorologist. The radiosonde allows us to create a vertical profile of temperature, wind speed/direction, and moisture. Of course, these variables are extremely important in the world of atmospheric science. It was pretty neat to be able to see real time data being sent in as the balloon rose through cloud base and into the upper atmosphere. Data was being plotted on a skew-T, which looks something like this. I won't bother explaining it, but you can visit this site if you are really interested in what you are looking at.



Eventually the balloon will pop somewhere around 70,000 ft (this varies). Because of the low pressures aloft, the balloon will expand almost to the size of a two story house. After it pops, the radiosonde will fall back to the ground on a parachute and most likely be lost forever. The National Weather Service puts a mailing address on their instruments asking for them to be returned, but the return rate is extremely low.

So from Monday through Friday, this was pretty much all that was done. Over the weekend, however, we had a whole bunch of work to do with the meteorological towers that we put up during the first week. At first, we thought the towers were only going to be a two week set-up, but some of the sites were interested in keeping them up for another few months. So we had to make a few adjustments to the towers to be able to make them withstand the longer stay.

15 concrete blocks were added to each leg to help the tower hold up against hurricane force winds (current estimates are that the tower will stand up against 90 mph). A trench had to be dug (with a machine of course) in order to bury the electrical line. A lightning protection system was also set up with a copper rod extending 3 feet above the tower and coiled copper wire running down the tower and 100 feet horizontally away from the tower underground. Here are some pictures of the trench.






For the lightning grounding system, we poured Bentonite into the trench below and on top of the copper wire to provide a greater surface area for electricity to flow. Bentonite holds water really well (cat litter uses the same stuff apparently), so this also helps in directing the flow of electricity.

That pretty much sums up the last week in Gulfport/Biloxi. Now its time to get some rest and try to regain some energy. I leave you with the one and only...Jimmy Buffett.

What Time is it Again?

Like I expected, this week has not been very tough at all. We've been launching radiosondes every two hours, and that is pretty much it. It really only takes 15 minutes to prepare the balloon, and then 1 hour and 45 minutes of sitting around and watching it. I really haven't had time to post any new entries because of the somewhat long hours and a few trips to the casino. I'll probably post a few pictures of the launches tomorrow, but I'm not promising anything.

So far this week, the high temperatures have been in the mid to high 90's with dewpoints in the high 60's. The rest of the research team that came down this week for the balloon launches have been complaining about how unbearable the heat is. The other two guys and I that came down last week just laugh when we hear this. Compared to the work we put in last week with temperatures in the 90's, this week is child's play.

Tomorrow is the last day of balloon launches for the Jackson State team, but the ATDD will continue launches through the weekend. At this point, we should be making our way back to Oak Ridge by Monday.

I'll post a review of this past week tomorrow, but trust me, it's not very thrilling/exciting work.

A common theme of this week, however, has been our inability to give the right time. ATDD works in some dumb time system that just confuses everybody. Life would be made so much easier if we just used Zulu time (like every other meteorological institution). In addition, we're in another time zone and some people don't reset their watches, so they constantly forget to subtract the hour from eastern time. Therefore, this song is dedicated to time, and how stupid it is.

A Day of Recollection

Today was a light day as far as actual work goes. We really only put in half a day going to the different sites and making sure everything was functioning as it should. Everything needs to be working properly by Tuesday, when the actual experiment begins. The rest of the research team will arrive Monday.

All of the hard work on this trip is pretty much done by this point. The rest of the time here in Gulfport simply involves launching weather balloons every two hours.

When I think back about all of the events of the past week, I realize that I have learned quite a lot.

For one, this field installment has reinforced the idea that the last thing I want to do for a job is sit behind a computer every day. By actually being out in the field, the days have flown by and I have enjoyed almost every minute of it. Even though the hours are sometimes long and tedious, its all worth it in the end. Therefore, it seems safe to say that when it comes time for job searching, I will be looking for a job that involves a good mix of field study combined with some data analyzation on the computer.

Secondly, I learned how to change a flat tire! Even though it wasn't difficult at all, it was still good experience...and I got to experience it twice (we had another blow out down here in Gulfport).

Finally, I learned that laughter is the cure of all ills, even when things start going wrong. When we were on the side of a highway in the middle of Alabama during the middle of the night, dead tired, with a flat tire, we never stopped laughing. By keeping a positive attitude , it is possible to get through even the most difficult situation.

With week 1/3 complete, I'm looking forward to a nice little break before we start the next phase. I'm also hoping to visit the casino tonight, but we'll see.

I had a hard time finding a theme song for this post, but I think this will work pretty well.

On the Top of the World

The last two days, not surprisingly, have been extremely busy. We've been putting in 12 hour days trying to get all of the necessary sites installed while working in 90 degree heat and dew points in the mid 70's. Yesterday consisted of installing and outfitting a 10 meter (30 feet) tower with the necessary instruments (wind speed, direction, temperature, radiation intensity, temperature). Pictures are included below.










Meanwhile, a friendly little creature decided to stop by and say hi. We eventually found his home, and stayed away. We later asked a local what kind of snake it was and he told us it was a coachwhip, which is not poisonous.






After installing this tower, we went to go talk to a few of the US Forest Service people to ask about our next installation at one of the local fire towers. This leads us to today.


Fire towers were originally built prior to WWII as a means of spotting wild fires in the distance. Today, however, with our current population spraw and constant connection via cell phones, they really are no longer needed. The particular fire tower that we climbed today was approximately 100 feet tall and was built sometime around 1930. The tower was pretty much original, except for new wooden stairways. We installed the same equipment at this site as we had at previous sites.



Working on the fire tower was actually much more difficult than installing our own tower because of the small space and the need to actually hang from the 100 foot tower. Let's just say I let the other guys do all the hanging...I just stood on the stairs and watched, that was good enough for me!

Today was another 11 hour day pretty much considering we left for the site at 7:00 am and didn't get back home until 6:00 pm. I also have a pretty nice sunburn on my arms and neck now from working in the hot southern sun for hours on end.

Too tired to write anything more, but enjoy the video of our fire tower climb!

The Long and Winding (and apparently too bumpy) Road

If I were to say that yesterday was one of the most tiring days ever, I wouldn't be lying. I woke up at 7am and went into work at 8. The morning was relatively quiet as people were doing various other tasks. We were supposed to leave Oak Ridge by noon, but we still had to disassemble all of the meteorological towers that we had assembled previously to see that everything functioned correctly. We didn't actually start until about 11 or so and we also had yet to pack a single trailer for the trip. Working in 90 degree heat, we took down all five of the towers (30 feet) and packed them away into the trailer. We also had to take down and pack all of the instruments, data loggers, and tools that we would need in Gulfport. By the time we got everything packed, it was 5:00. We didn't actually get out of Oak Ridge until 5:30.

Having already logged a nine hour day, we still had a ten hour drive ahead of us! The first half of the trip flew by pretty fast as we drove through Tennessee and into Alabama. This was the first time I had ever been in Alabama, and lets just say, no great loss. If you like trees, and nothing, then Alabama is the place for you.

Unfortunately, all good things must come to an end. At about the halfway mark of the trip, the tire on one of our trailers decided to completely blow up. I was riding in the vehicle behind the trailer and we were talking to the other guy on the phone. He was saying how something didn't feel right, and then the tire just exploded. After a few seconds, the fender was torn off and went flying 100 feet in the air (okay...that was an exaggeration, but it was still pretty awesome). So, for the next half an hour, we changed the trailer tire on a highway somewhere in the middle of Alabama. For the next six hours, we kept our speed at 60 and stopped frequently to check on the spare that we put on. We didn't actually arrive in Gulfport until 5 am.

Tomorrow we will actually start the installation process at a nearby airport. Understandably, we weren't in the best condition today to do much of anything. I'll make sure to have a whole bunch of pictures up tomorrow.

As for today, we drove around for a little bit trying to figure a few things out. Downtown Biloxi is basically a small Las Vegas with casinos lining the shore. You can also see the obvious effects of hurricanes on the city with downed trees and sand everywhere. Overall, its a nice little tourist spot. I'll definetly visit these places over the next few weeks. Right now all I want to do is sleep!

This is also the first time i've been in another time zone (I know...I'm lame), so thats pretty cool!
Well, I think it's time to get some rest and get ready for another long day tomorrow.

Going to Gulfport

Well, this Monday I officially depart Oak Ridge for a few weeks and travel to Gulfport/Biloxi, MS. The first week I will be assisting a few of the engineers in setting up meteorological towers and instruments. During the second week, I will be launching radiosondes every two hours. More of this in another post. Hours will be approximately from 7am-7pm M-F. During my two week hiatus, I will definitely visit a few of the beaches and casinos in the Gulfport/Biloxi area. It will also be interesting to see the extent of damage caused by Katrina in 2006. That's all for now, here's a video to end with.

It's All About Stability

The main goal of this research project in Oak Ridge is to find a connection between PM concentrations and the overall stability of the atmosphere. Oak Ridge National Laboratory has done extensive research at the I-40/Watt Road Interchange, but it the belief of my mentor that they incorrectly theorized the reasons for the existence of PM diurnal oscillations.

In 2006, ORNL performed a huge field study where they analyzed truck and vehicle emissions along the I40 interchange. From this study, it was determined that 100,000 vehicles pass this site per day, with 20,000 of those vehicles consisting of trucks. In the three nearby truck stops, there were over 700 parking spaces. The picture of this interchange can be seen below.


Additionally, it was found that idling trucks at the truck stop produced much more PM2.5 than those moving at constant speed along the highway. This was a significant find, considering that over 60% of trucks were found to be idling their engines when parked in their spaces. When observing the daily concentration of PM2.5, they noticed a clear spike in concentrations during the overnight hours. This is the prime time for trucks to be idling their engines at the truck stop (when most truckers sleep, they leave their engines idling in order to provide air conditioning, and that constant hum that helps them sleep). Therefore, ORNL concluded that the nocturnal spike was due solely to an increase in idling trucks.

Meteorologists, however, are more than familar with pollution buildups during overnight hours.

Overnight, as the ground cools much more quickly than the surrounding air, a temperature inversion develops in the lowest 1000 m of the atmosphere. An inversion is simply a layer where temperature actually increases with height (normally, temperature decreases with height). Because of this increase, this layer is an extremely stable area that limits vertical movement and acts as a lid. Therefore, any source pollution present is unable to disperse and is kept at the surface. When located in a valley, between two ridges, almost all movement is entirely suppressed. Not surprisingly, the I-40/Watt Road interchange is located in a valley between two ridges approximately 300ft above the surrounding valley.

At the ATDD's site at Watt Road, we are measuring PM concentrations in addition to 3 and 10 meter temperatures and wind components. We will use the wind and temperature measurements to compute stability indices. I will discuss this in another post. For right now, I just want to discuss the effects of the inversion.

Inversions can be easily identified on radar during the early morning hours. Because of their stability, inversions are capable of bending radar beams into the ground and causing the radar to pick up the back scatter of the ground (trees, cars, etc) instead of actual rain drops. The image below shows an example of the effects of an inversion on radar.



As soon as the sun rises, however, the ground begins to warm more quickly than the surrounding air, resulting in the break down of this inversion. Below, you will find a time series of this breakdown obtained on June 3rd in Knoxville. Throughout the half hour time period, you will notice the intensity of the colors decreasing, an indication of the breakdown of the inversion.

7:30am



7:41 am


8:00


Theoretically, with the breakdown of this inversion, turbulent mixing in the lowest 1000 meters should quickly take over, resulting in the dispersion of anything that has built up overnight. Below is a graph of PM concentrations (in ug/m^3) obtained during this same day.



As can be seen, at around 7:30 am, PM concentrations fell from a max of 33 ug/m^3 to 20 ug/m^3 over a time period of about a half hour. Not surprisingly, this drop corresponds with the breakdown of the inversion! TA DA!

This quick and simple inversion example that I found earlier this week has shown that stability is most likely the controlling factor in PM concentrations.

The next step in this project is to use sophisticated techniques to measure stability and really prove that this is a major issue in diurnal oscillations. Sorry ORNL, maybe next time....

Those Pesky Particles

As has been stated previously, the main objective of this research is to study the concentration of PM2.5 particles in the atmosphere. Of course, these are particles with diameters less than 2.5 microns (although this is much more complicated than it seems since these particles aren't spherical!) Because of their small size, these fine particles are capable of entering the respiratory system and wreaking havoc on the passageways of the lungs. Additional research, however, still must be performed to determine whether short-term instantaneous peak concentration is more harmful than long-term exposure. Current research is focusing on this topic, but is outside the realm of my research.

Although the difference between 2.5 micron particles and 10 micron particles may seem small, there is a huge difference as far as radiative and chemical properties. Because of their radiative and chemical differences, differentiating between these particles is essential. Atmospheric scientists have therefore divided the particulates into three categories; those particles smaller than 2.5 um, particles between 2.5 um and 10 microns, and particles greater than 10um. By differentiating between these fine and course particles, we are better able to judge the impact of these particles on the environment and human welfare.

Although my research focuses solely on those PM2.5 particles produced by traffic, there are numerous other sources that you wouldn't even think of. Let's start with some indoor causes:

1) Cooking, for example, is a main cause for indoor air pollution as these particles are easily suspended. In fact, grilling meat outdoors is a huge concern during periods of stagnant weather because of their uptake into the surrounding environment. You can only guess how much charbroiled meat you just breathed in during Memorial Day Weekend!

So, I guess it really does rain meatballs. (and there's also a movie coming out, who would have guessed?)

2) Dust from human and pet fibers also are found extensively.

3) Smoking, duh.

4) Cleaning substances.




The image above was obtained from the EPA analysis of outdoor and indoor PM concentration. The paper was titled Air Quality Criteria for Particulate Matter and was released in October of 2004.

This post could go on forever detailing all of the sources of particulate matter, but I will spare you. I think you get the point that these particles can be found readily in the environment from a variety of sources.

I'll conclude with the possible health consequences, and the true reasons why this research is vital for human health.

As we progress through life, taking the next breath is the last thing on our mind. As adults, we average almost twenty breaths per minute, yet it is often as involuntary as the beating of our heart. We breath while we sleep, while we exercise, and while we eat, and meanwhile our lungs just keep on pumping. But what if, one day, our lungs decided they were sick of doing all of the hard work. What if you had to struggle to inhale and every breath felt like it may just be the last?

Ask any child who suffers from asthma and they will tell you exactly how it feels. Sit by the elderly man in the nursing home who suffers from COPD, and he will tell you the pain and fear he experiences. Observe the retired coal miners whose lungs are as black as the coal they mined and they will tell you the continual struggle.

Although studying air quality may not be as exciting as chasing tornadoes and hurricanes, it can be just as deadly (if not more so). It is, in fact, a silent killer that can take years to act and will inflict more misery than any EF-5 tornado could ever produce.

As our population continues to skyrocket, and industry explodes across the world, it is the duty of our generation to find a cure. With all of our technological advancements, it is ridiculous to rely on a fuel that is as old as the car itself. Unfortunately, politics and money are the root cause of this utter failure. Once again, Thoreau comes to the rescue with his wise advice.

"If a man loses pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured, or far away."
- Henry David Thoreau