24 August 1995
PH: A summary overview of this flight. Good news is that there are lots of fires and lots of smoke north of Cuiaba. We first did a vertical profile in fairly clean air over the NASA sunphotometer located at INPE in the north part of town. Then, we proceeded north, and saw all sorts of individual fires as we went out. Then we went through an area that was relatively fire free. Then, as we proceeded north, we got into some very thick smoke from quite a few big fires and we flew just below the inversion, probably the base of the inversion, for quite a way in moderate smoke. We then saw a big cumulus coming up from a tall smoke plume ahead of us so we headed for that. Climbed to over 10,000 ft and tried to get some measurements of smoke around the top of the cumulus, just above the top of the cumulus, and we passed through smoke a few times doing that. We then dropped down and passed through the cumulus cloud itself a few times. Didn't see much. I'm wondering if the FSSP was working because I didn't see much liquid water. We then dropped down below the base of that cloud and went through the smoke once for a full set of measurements. And then, unfortunately, Ken decided that he wanted to head back even though we were only 1 1/2 hours into the flight because he had no contact with Cuiaba and he wanted to make sure it was still open. So we headed back, which was a pity because if we had another half an hour to 45 mins to spend on that smoke-cloud interaction situation there I think we could have done a much better job. Anyway, we headed back and got into an area, I'm not quite sure how far out from Cuiaba, where Ken had made contact with Cuiaba control and found out it was still open there, so no problem. We had an hour to spend in that area where there were a lot of fires. So we went through, I forget how many, 1, 2, 3, or so plumes.
PH: Spent quite a bit of time on the last plume sampling it several distances downwind. We were limited in what we could do because Ron ran out of filters. But, prior to that, we did several emission factor measurements on individual plumes in that area. And then we headed back. So that's a quick summary. It's all on the tape, but that's a quick summary of what we did on this flight. Quite a few things. Now we will do some individual summaries. Ron? Would you like to summarize what you did?
RF: We took a couple of bags over the profile of the sunphotometer to get a background sample out of the smoke and then we went up to that forest fire up to the north. We got a good filter sample at the top of the cumulus where it was coming out of the top of the forest fire and then another good sample at smoke and cloud base and then just after that we turned upwind to get a background can for upwind hydrocarbons. On the way back towards Cuiaba, we hit two individual plumes and we sampled for emission factors in both of them with a background filter collected in-between those two as we headed south. And both of those were pretty blackish looking smoke so I think we got good emission factors on them.
PH: Ray?
RW: The OEC-nephelometer system worked pretty well and I pretty much measured every single time we went through. When the extinction coefficient gets above about oh, high 10-4 or up into the 10-3, its getting pretty good data. And Ron is right, the smoke does appear to be fairly black, single-scattering albedos in the neighborhood of 0.66 to 0.7, which is pretty black for biomass. A3 I don't know because I haven't been able to look at the data. The humidigraph I didn't have much opportunity to really use it today. The one that I did take didn't appear to indicate any hygroscopic growth so I don't know if it's working. The RH seems to be sweeping properly and I measured the temperatures on both the inlet and the outlet of the nephelometer and they weren't that much different. So I don't know. Other than that, I think it's the best data I've gotten for optical measurements anyway. I took a lot of aerosol size distributions, probably 30, so. Anyway that's about it.
PH: Okay. A couple of additional things. I forgot to mention that we did some lidar measurements along the length of and across the width of the last plume that we looked at. The second thing, I think, apart from the last plume, that we looked at we were looking at grass burning. The last plume, however, was more tree burning. Thirdly, if we are going to look at old smoke in this area, we are going to have to get away from all this local fire smoke that was dominating the situation out to as far north as we went today. We are going to have to get further north and hope we get away from local burning to look at old fire smoke from the Alta Floresta area. Okay. Don?
DS: Well, the CCN worked pretty well today. Got some reasonably high concentrations of CCN. Towards the end of the flight though it began to shut down. That was about when we switched over to the lidar. Tomorrow we probably won't have a problem because we should have our blue ices entirely frozen. At this point the reason it failed, I would guess, would be because the blue ice basically was not cooling it down. And that's about that.
PH: Okay. Art?
AR: This is a day where we saw the inversion height a little lower than we did in the Brazilia area, about 8,500 ft. There were no natural clouds in the area. The only clouds formed at the top of the hottest fires that extended to about 4,000 ft above the general level of the haze layer and those turrets would turn white for maybe one or two minutes at the most and then disappear, which would suggest that there were droplets there and I'm sure there were. They were very small and probably didn't even reach 10 microns with the number of droplets and the short time that they survived. And at that point, one or two minutes, the turrets would turn completely to brown and sometimes we weren't able to get back in time to get the white part of the cloud. Other than that, everything seemed to be okay. Seemed like a decent flight, though there was some question over the FSSP data at this point and I'll check that after the flight.
PH: Okay. Jason?
JL: First of all Valero's TDDR instrument behaved superbly today. It popped it's head and everything looks fine. For CAR we had some interesting results over that smoky cloud layer. In particular when we were inside as well as we were under it. So it is something interesting to look at when we go back.
PH: What particular smoky area are you taking about there? The big fire we worked or the general pall of smoke or the individual fires?
JL: The biggest one we were investigating there.
PH: All right that was the earlier one with the cumulus cloud on top.
JL: Yes.
PH: Okay.
AR: Peter, I did want to add that I took some video of these fires early on.
PH: Okay. Good. Jack says everything as far as he can tell worked okay today. So that's it. We're heading in to land.