Thursday, June 3, 2010
It was an interesting day at the airport. The aircraft crew resolved the issue with the ground power, and the G-1 was up and ready to fly in the morning.
Now, as I had explained on May 31, the unique summertime meteorology in Sacramento area was the primary reason for selecting this site for CARES. The other motivation was the opportunity to collaborate with the CalNex field study that is also taking place presently in California. As part of CalNex, the National Oceanic & Atmospheric Administration (NOAA) is deploying their WP-3 and Twin Otter Remote Sensing aircraft and the R/V Atlantis ship to make measurements of air pollutants and their climate-affecting properties in and around California. We plan to coordinate our sampling with them as opportunities arise.
In fact, an opportunity to coordinate the G-1 flight with R/V Atlantis arose today. I had been in touch with the ship's principal investigator, Patricia Quinn of NOAA's Pacific Marine Environmental Laboratory, the last few days regarding this possible coordination as the ship was working its way up the California coast from Los Angeles to Sacramento. I learned yesterday that the ship will be moving up the Sacramento River today and be in our sampling domain by 1:00 PM.
So, after the weather briefing at 9:15 AM, we all swung into action to develop a flight plan in which the G-1 would fly vertical spirals over the ship at a few different altitudes between 1000 and 5000 feet. The NASA B-200 would also fly over the G-1 at 28,000 feet, as well as perform additional maneuvers to scope the larger domain with their remote sensing instruments. Both aircraft took off around 12:30 PM and completed their missions without a hitch. The G-1 was able to meet up with the ship between 13:13 and 14:04 do vertical profiles over it as planned. John Hubbe managed to take a nice picture of the ship.
A debriefing was held at 4 PM, where the pilots, flight engineers, and instrument principal investigators reported how everything performed. Some minor problems with a couple of instruments were discovered, but the overall mission was deemed quite successful!
Tomorrow is the CARES media day, where reporters will visit the American River College site and the airport to see what we are up to. Read the press release here.
Wednesday, June 2, 2010
Today marks the official start of the CARES field campaign. As planned, several state-of-the-art instruments at both the ground sites began making measurements of aerosol size, concentration, composition and their climate-affecting properties. A number of instruments that measure concentrations of pollutant gases such as ozone, carbon monoxide, sulfur dioxide, nitrogen oxides, and selected organic compounds emitted from vehicle exhaust and vegetation also kicked into action. However, most of these instruments hardly "saw" any signs of pollution. It was a gorgeous day outside, and the air appeared to be exceptionally clean. This was quite disappointing, at least initially. As the day progressed, we saw massive amounts of very small particles appear at both the ground sites.
While it will take several weeks or months to analyze all the data from just this one day and figure out the source(s) and evolution of these particles, our guess is that they may have formed via oxidation of natural organic gases emitted from trees. Such new particle formation events, which tend to occur quite efficiently under very clean conditions, are the nature's way of maintaining a certain concentration of atmospheric aerosols, some of which lead to cloud formation and rain. Such processes are still rather poorly understood and not well represented in computer models that simulate the effects of aerosols on climate. So, the apparently clean and boring day turned out to be quite exciting after all.
Back at the airport we ran into some last-minute glitches with the G-1 aircraft, and decided to postpone the first flight until those issues are resolved. Like I said in the previous blog entry, it always takes a few days to spin up after the aircraft arrives at the field site. This campaign is no exception. The AAF folks are working hard at it, and they expect to get the G-1 up again very soon.
So, we are off to an exciting start, and hope to collect lots of interesting data over the next 4 weeks.
Tuesday, June 1, 2010
I cannot believe it's already been a week since we started setting up the ground sites. As you can see, a lot has happened here in the last few days. The basic infrastructure—trailer space, power, air conditioning, internet, inlet systems, compressed gases, security—was put in place at both ground sites in less than a week! Kudos to the entire PNNL ground site setup team led by Will Shaw and Dan Cziczo. Will and Dan are also the co-principal investigators of the CARES field study.
All the different research groups have also been hard at work and have pretty much settled down in their spots in the trailers with their "babies," and most look quite happy. Some remaining minor issues will hopefully be taken care of in the next couple of days.
Tom Jobson of WSU and Dan Cziczo are going to oversee the daily operations at the T0 and T1 sites, respectively. Most of the ground sites folks who are staying in Roseville, a suburb of Sacramento, have been meeting every night at 9 o'clock to give everybody an update on their instrument status, and we plan to continue doing this in the days to come.
The DOE G-1 and NASA B-200 aircraft teams have nearly settled into their offices at McClellan Jet Services, which provides full airport FBO services, 24/7. It's quite nice, and I was particularly impressed with the size of their hangars. They are huge!
G-1's new chief pilot, Mike Hubbell, gave the flight safety briefing at 4:00 PM, and the first aircraft science meeting was held at 7:00 PM. We are planning to have our first flight tomorrow afternoon to make sure all the instruments are performing as expected. It always takes a few days to spin up after arriving at the field site.
The study officially begins tomorrow, and everybody's quite excited and anxious at the same time.