Flight Number: 970202H1 Page 1 of
Date: February 2, 1997 Aircraft ID: 42 Scientist: Jorgensen
Event Log
Time Approx. Location Event & Comments (UTC) (Lat, Lon) 15:19:51 Shannon Engine Start This is mission #5 IOP 9 15:23:34 Shannon Block out 15:32:04 52.708 -8.912 take off 16:04:57 Radar recording on since 1552 Z 16:09:14 53.913 -12.139 500 mb winds agree well with the LAM analysis. Timing of the pattern may be a bit slow since I assumed 200/40 and we actually have a slight headwind with winds no 280/34. 16:14:05 500 mb (5.57 km) altitude TAS is 285 knots 16:16:36 54.180 -12.873 Entering heavy overcast above 16:21:41 Looks like we'll be about one half hour late arriving at pt 1. 16:43:35 55.953 -14.193 Over buoy - turn to 319 to track to pt 1, ETA about 1800 UTC 16:45:32 56.043 -14.311 broken sky above - TA indicates light echo below 16:50:36 56.340 -14.746 small particle images on PMS display - very light echo indicated on TA 17:37:01 59.431 -17.796 precip cells evident on TA to the left max dBZ 25-30 17:54:05 60.555 -19.053 Entered our airspace "box" - climbing up to 22k ft PA ~21 kft RA 427 mb 18:04:38 61.121 -20.110 at pt 1 - turn to track west 18:05:37 61.147 -20.239 drop #1 18:07:02 61.161 -20.434 Icelandic coast outlined on LF at 150-200 nm north 18:07:37 lost #1 about 80 seconds into the drop - no return on TA to speak of 18:21:56 61.312 -22.492 drop #2 - bright band now showing up on TA below us - indications of curved bands on LF 100 nm to the south 18:24:53 61.336 -22.901 Drop # 2 died too 18:25:14 61.340 -22.950 drop #3 - replacement for #2 away 18:30:25 sonde #3 also lost signal - maybe problem with reciever - looking into problem 18:36:45 61.433 -24.563 sonde #4 at drop location 3 18:44:07 sonde #4 also lost signal 18:51:38 61.519 -26.707 sonde #5 away at drop location 4 18:52:30 lost signal on sonde #5 19:03:26 holding off on sonde drops until problem is diagnosed. If it isn't fixed by pt 3, then will descend to 5 kft for Doppler run across low center. 19:05:11 61.569 -28.726 more bands evident on LF 100 nm to south. 3 bands spaced by 10-20 miles or so oriented east-west with some curvature to the south 19:05:47 61.570 -28.813 end of leg at pt 2, turning to track south to pt 3 - climb up 19:09:04 61.354 -28.810 more precip being seen by TA - bright band more evident 19:16:51 60.796 -28.730 sonde #5 away at location 4 half-way between pt 2 and pt 3 19:21:51 lost signal on sonde 5 - working on problem under the floor 19:26:46 60.065 -28.673 at point 3 starting spiral descent to 5k ft for run across cloud head band 19:31:23 stopping descent to launch another sonde for a test continuting to spiral at pt 3 19:32:34 60.042 -28.919 sonde #6 away at 13 kft for a test, continuing to spiral and hold at this altitude. Useful as a perl as we're in very light precip. 19:34:47 lost signal on sonde #6 - possible antenna problem. Resuming the descent to 5k ft. 19:39:55 60.050 -28.787 start leg 2 eastbound toward pt 4 at 5k ft. Looks like we'll be cutting through the cloud head band. 19:50:07 60.158 -27.620 start perl #1 to the right 19:53:05 end of perl - resume track to east 19:56:20 60.184 -27.266 band of ~30 dBZ echo 40-50 nm to our south oriented toward 070 - warm frontal band? 20:03:28 60.240 -26.450 band about 40 nm to our south better defined with max dBZ to about 40 20:05:26 60.248 -26.226 start perl #2 in fairly moderate stratiform precip 20:08:08 end of perl resume eastbound track 20:15:55 60.297 -25.405 sloping shear layer on TA - ascending air over the warm front? slope from right (low level) to left (high level) ascending air sloping upward from south to north. 20:23:10 60.338 -24.585 start perl #3 in middle of cloud head band- bands of precip still evident on LF oriented toward 050 or so, max dBZ up to about 40 20:25:02 changed antennas on the dropsonde system will spiral up at the end of the leg to try another test 20:26:12 end of perl, resume eastbound track 20:27:26 too hot for the C-scat - it quit working at 1950 UTC 20:29:53 60.360 -24.212 east-west oriented precip bands now on both sides of track on LF. flight levels winds now 130/37 indicating we're now on the east side of the low center 20:41:55 60.362 -22.894 start perl #4 in moderate precip of cloud head 20:44:20 end of perl, resume eastbound track 20:51:10 60.417 -22.134 large particles on the 2D-P display 2-3 mm diameter or so - aggregates of various shapes 21:06:46 60.451 -20.266 end of leg-at pt 4-climbing spiral and perl to the right in light stratiform precip. Will try another sonde test when we get to 15kft. No contact with 308D as yet 21:14:18 60.471 -20.198 at 15k ft 21:15:46 60.430 -20.327 sonde #7 away 21:17:23 lost contact with sonde. Descending back to 5k ft for rest of pattern-trk south to pt 5 21:35:46 C-scat back up 21:38:40 59.567 -20.369 some turbulence going thourgh a small convectiv line. TA shows more convective type cell structure 21:46:50 59.176 -20.409 brief contact with 308D before contact lost 21:52:39 58.956 -20.591 going through n-s oriented band 21:53:15 contact with 308D - passed along advice about this n-s band at 20.5W 21:59:01 58.996 -21.230 going through a small line of convective cells that are highly sheared from south to north 22:06:14 59.049 -21.985 going through a group of convective cells oriented N-S. Line only about 20 miles long but max dBZ is about 35-40. Cold air convection? 22:15:05 59.118 -22.922 sfc press down to 983 22:21:16 59.162 -23.570 end of leg, out of endurance turn and climb for trip back to SNN 23:08:38 57.134 -17.198 going through a region of light stratiform precip as we track 122 toward the northern buoy 23:31:31 55.932 -14.200 over buoy, trk toward SNN 23:47:00 radar recording suspended 0:32:40 SNN land 0:38:14 SNN block in