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