DC-8 Mission Science Report

Coordinated 3-aircraft mission with KAMP/TRMM objectives. First priority is precipitation close to the KAMP surface assets, alternate targets over the Gulf of Mexico. TRMM overpass to cover ares with TMI data only near 1830 Z.

Obtain data from stacked aircraft (P3, DC8, ER2) in precipitation. If a sufficiently large region of stratiform precipitation is within reach, obtain mnicrophysics data in spiral descents through the ice region and melting band to +6 C.

Mostly a successful mission in very interesting weather systems. The strategic decisions were being made by Mike Biggerstaff aboard the P3. The major decision was made early in the mission to pass up the smaller targets in the Keys area in favor of the "bird-in-hand" theory of getting the sure thing, a rather large MCS west of the Ft. Myers area, between 25-27 N and 83-85 W. After several passes through and along lines on the east side of the complex, the DC8 and P3 executed the spiral descent from 28000' PA (329 mb; -26.5 C) to about +6 C (DC8). The area was very well-chosen as the area of precipitating snow was very extensive; intensity seemed rather light as the sea aurface was clearly visible from a temperature of about -4 C and visibility excellent in the rain. No clouds at all below the snow, as one would expect. After the spiral, the DC8 and ER2 worked a line a little NE of the original line on the east side of the system. The P3 started on the line but had to leave when a lightning strike broke the HF antenna. Despite excellent cooperation by all, the communication difficulties encountered in this type of mission led to some inefficiencies in spite of a successful overall mission. The early lines were not communicated by the P3 quickly enough for all aircraft to get on the line at the same time. The P3 and DC8 spirals were not covered by the ER2, which never received the new coordinates for the spiral (the originally-suggested spiral location had been along the early line). The lightning strikes to the P3, and the strength of the updrafts at their altitude, were exceptional considering the light turbulence at DC8 altitude. That aspect alone of the system will make it worthy of detailed study.