Objective: Our first objective is to profile a multilayer cloud structure over the CART site to provide ground truth for the radar. Our second objective is to make persistent contrails with the DC-8 for the ER-2 to observe and for us to sample. Our third objective is to sample the outflow of air from a convective cloud and compare that with boundary layer air so that we can see how aerosols in the upper troposphere, processed by cloud, compare with those in the boundary layer.
Instruments: All of the instruments are functional.
Meteorology expected: We expect high, middle and low clouds over the CART site. We also expect a line of convection near the Texas, Oklahoma border with isolated cells possible near us.
Flight plan: The plan is to pick a point about 15 min. upwind of the CART site and to fly constant altitude legs between that point and the CART site. First we will fly a leg near 20kft below cloud deck for the radiation instruments. Then we will fly a leg near 25kft for maximum radar return. Then we will fly a leg near 30kft at cloud top. Then we will fly multiple legs near the trop to make contrails. Over the CART site we will fly 3 360 degree turns so that we can sample the contrail. At the downwind point we will turn and try to fly up the contrail. After about three hours we will look for an isolated thunderhead, and fly around it at the altitude of the anvil. Next we will circle about 20kft. Finally we will fly a leg in the boundary layer.
Report on meteorology observed: The meteorology was close to predicted. There were low level clouds below 10kft over the CART site. Then a middle level cirrus from about 18-30 kft. Next a thin cirrus near the trop at about 35 kft. There were clear gaps between the cloud layers. The middle level cirrus was fairly uniform. In the afternoon a line of convection developed near the CART site and eventually moved over the CART site. We did find an isolated developing cell with an anvil about 30 miles long. The cloud top was near 40kft and the anvil tip near 29kft
Report on flight plan as flown: We flew the fight as planned. We flew legs near 16, 24, and 31kft based on CART reports on cloud base, max. radar return and cloud top. Then we made contrails near 35 and 36kft. Although we did make many passes through our contrail we were not able to see it well enough to remain within it. We also did a flight around the cumulus. We circled the top which did not allow long enough to sample the outflow air with the slowest sensors. However, we did not detect much air flowing out. Evidently the cloud was still spreading. So we may not be able to sample the processed aerosol this way.
Report on instrument performance: