12 September 1995
PH: Okay. I'm going to start summarizing this flight. This flight has been pretty much devoted to individual plume sampling and smoke-cloud interactions in the region of Repressa Samuel around the reservoir here. First of all we sampled a large slash burn. Got measurements of emission factors, a number of other penetrations of the plume and then we spent some time sampling the cloud produced by that fire all the way up to about 13,000 ft or so and we should have got some good outflow smoke samples as well as smoke in the cloud. We found it easier to get smoke just below cloud top than coming out of the cloud. We then came back down again, got some more cloud samples on the way down. We then went back to the source of the fire, by which time it was pretty much dying out. We then did a few individual slash burns, and we then spotted a black plume from grass burning, flaming burning. Most of the rest of the smoke we had sampled today was primarily smoldering, but the grass was flaming producing black smoke. We got some emission factor measurements and physical measurements on that. Finally, as we climb up here we are going to see if we can hit a few of these little clouds produced by the various fires around here. Ray, ready for summary?
RW: The aerosol gave quite good optical measurements. The tallest smoke throughout the area is very, very white with very little black carbon content. Most of the individual smoldering plumes were very white. Grass fire at the end was very dark. Estimated 25% or so black carbon aerosol mass because we got about 50% single scattering albedo. And all in all, I think, a pretty complete set of measurements.
PH: One remarkable thing to note here is the difference between the number of fires that we are seeing here this afternoon and what we saw Monday morning.
RF: I think it was really useful to do these fires. Because when we've been flying in this area, we've been seeing a lot of smoldering fires that are the leftovers of these kinds of things. So it was good today that we got two of them in the beginning phase and I think things will be quite different from what we've seen on the remnants a day later.
RF: Like I was saying, it was good to see some of those fires in this area that are the ones we've gotten the remnants of in the past few days. Early on we caught that fire when they were starting it and got a real good sample for emission factors. Loaded up quite a lot of filters today.
PH: Which fire are you talking about, Ron?
RF: The first one we started working in detail. And that was about 460 parts per million of CO2 in the bag so that was a really good sample for emission factors and we got the full suite of filters on that one bag. And then, we got another bag and filters when we were getting that air up between the cumulus clouds. And we also ran Nuclepores for Jeff and Vanderlei to do SEM on. So we'll be able to see if those particles are qualitatively different shapes than from the ones that had gone through the cloud. The usual 3 1/2 hr MOUDI and Mercury samples. And then, let's see, several more filters for when we were looking at what I call processed smoke up there around the cloud or in the cloud. Lot of good hot and cold DMPS data on just about every bag and a couple of really good samples on this black smoke from this grass fire that started up late in the flight. So all in all, I think we did real well.
PH: Okay, Don, summarize.
DS: The CCN worked quite well today. Differences that we got concentrations up around somewhere between 5 and 12,000 to 20,000 depending on which plume we looked at down low. Going up through the clouds was a dramatic drop in the CCN of the stuff that was processed. Went from the higher levels to from 5 down to about 2,000. Valero's radiometers I have been keeping an eye on. They have been working. Changed the gain on the CAR a couple of times to keep in within specifications.