17 September 1995
RF: Okay. Flight summary here. We started off doing regional haze. There wasn't much in the way of fire activity around the area we were flying, which was a north and south track along 48.3[[ring]] longitude. There were two layers. One above these cumulus at about 5,000 to 7,000 ft and one below that was pretty different in total concentrations. The one aloft extended up to about 13,000 ft. We climbed up and profiled that and started doing north-south legs running along that track. Did filters above the clouds, at cloud level, between the clouds, collected cloud water in the clouds and then sampled the boundary layer below the clouds. About this time, we could see some of the smaller fires that had been smoldering earlier in the day had really taken off. So, we were working an area where it was brush and palm trees that really kind of flared up. We started working that plume where there was a lot of flaming combustion. We got a good sample of smoke in-cloud above that fire. Then we dropped down and did a sample for emission factors. In the meantime, another fire flared up just south of there, which was primarily a grass field. It looked like they had just started it, because it was burning all around the perimeter of the field along the road. So, when we finished with the first fire and came over there, the entire field was engulfed and it was burning in towards the center from the outer edges. And very black smoke coming off that. We sampled that once for emission factors and made about three penetrations of it for the extinction cell. Then we climbed up and got another pass through the cloud that was over that fire at about 1,000 ft above cloud base. Then, on the way home, we sampled the cumulus cloud over the first fire and got a good sample of smoke exiting the cumulus there. So, I think we made about the most we could out of the remaining time with those two fires. And both fires kicked off very large cumulus clouds. The one on the first fire as we were exiting the area we were getting raindrops on the windshield. So, I think that was all part of that complex that was kicked off by that fire.
Anybody else have things to add for summary of the flight.
JSR: I think you just about covered it. The one thing that I would note is on that big grass fire. We had SO2 pegged at the half a part per million level, that was the first fire, and then when we went back to it and looked at the smoke exiting the cloud all of the SO2 was essentially scrubbed.
JR: I think all of the instrumentation looked okay. I didn't see anything wrong.
RW: These were clearly the biggest fires we've seen and the most aggressive burning. The optical information, at least on the second part, was very, very black, probably 50% absorbing. There seemed to be some A3 activity and also the humidigraph showed particle growth. So, all in all, it was some pretty good fires.