Flight Report, Flight #28, 12 December, 1995
Stratocumulus-Radiation, Ship Flux intercomparison

2301                Takeoff Hobart, climb to 18,000'
2320-0035           level at 18,000' above altostratus enroute to stratocumulus region
0012           Approaching edge of altostratus deck - not clear to stratocumulus below
0030           Discussion with Ace-operations revealed that statocumulus field was 
               closed in above by altostratus
0035                retrun heading for radiation runs in altostratus

0050:50-0105:50     Lidar leg at 13,000' altitude above altostratus - 45S 144E
0110:40-0125:40     Radiation leg at 8500' about 300' below altostratus base - high OH
0129:30-0144:30     Radiation leg at 11,100' about 300' above altostratus top
0148:20-0203:20     Radiation leg at 10,500' in cloud about 200' below cloud top 

0020-0035      Profiling of stratucumulus below altostratus - 45.2S 143.6E
0246           Head west along stratucumulus top to 46S 143E
0305           Turn NE toward ship continuing along stratucumulus top

0322:55-0352:55     CW 30 min Lenschow circle at 100' - patches of drizzle
               start 45.1S 144.3E
0359:05-0429:05     CCW 30 min Lenschow circle at 100' - much less drizzle
               start 45.1 S 144.1E
0436:35-0506:35     CW 30 min Lenschow circle at 500'
               start 45.3S 144.4E
0508-0518      Porpoise leg along inversion
0518-0528      Extend for calibration below inversion
0532-0552      cloud top-following leg
0555:30-0525:30     CW 30 min Lenschow circle at 100'
               start 44.3S 145E
0526-0546      Sounding above circle to 10,000' at 500'/min
0546           Climb to 15,000' for return to Hobart
0630           Land at Hobart

The objectives of this flight were to measure the radiation environment and microphysics of
stratocumulus and produce a flux intercomparison with Disco.  On transit out to the expected
stratocumulus region conversation with Ace-operation indicated that the stratocu was covered
by altostratus.  The altostratus was very uniform and flat so radiation legs were flown on that
cloud deck.  The cloud top was at about 10,800' and was about 600' thick.  Fifteen minute
runs were made at 300' below the cloud base, 300' above the cloud top, and in the cloud
about 200' below cloud top.  Very high OH observations were reported above and below the
altostratus layer.

Radio conversations with Disco revealed poor weather including drizzle and weak inversion
aloft.  Stratocumulus below that altostratus was selected for profiling of cloud droplet
characteristics.

We then approached Disco with the intent to fly straight legs for consentrations of gases if
drizzle was present and circles for fluxes if drizzle was absent.  The profile down to the
vicinity of Disco revealed a weak inversion at about 1200' with a mixed layer below to the
surface.  The profile aloft showed increasing theta to a second inverion at about 2200-2400. 
Stratocumulus populated a layer variably from 1000' to the upper inversion.  No drizzle was
reported at Disco (5 nm north) and so a circle was flown at 100'.  

The first circle at 100' was judged to be too inhomogenious (CN varied from 750 to 250/cc)
and contaminated by drizzle.  Therefore a second circle was flown 20nm to the west.  This
circle was was much more homogeneous (CN about 250) and very little drizzle was reported.
We flew the next circle at 500' and then porpoised across the top for entrainment estimates. 
The entire layer from 1000' to 2200' was included in the porpoise to characterize the layer up
to the second inversion.  We then flew a final circle at 100' for time-differences.  A profile
above the circle at 500'/min ended the maneuvers for this flight.  The profile revealed as
many as five distinct stable layers from the surface mixed layer up the the altostratus layer at
about 10,000'.  The low solar flux in the surface mixed layer may help interpret the flux
calculations.