TIME (UTC) REMARKS
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1533:52 Takeoff Hobart.
1551:30 Leveloff at 16,000'. Wind speed about 3 ms$^{-1}$
at ferry level.
1609:33 Bright moon. Scattered cu visible in moonlight.
Cu top is estimated to be 4500'. Large clear area visible.
1627:16 Selected one clear area at around -42.54S, 142.34E.
1630:31 Start descend at 1000 fpm rate, clear below, cu cloud
around. Descending rate is 1000 fpm.
1639:50 Reached 7000', start slow descending rate at
500 fpm.
1647:08 Reach BL top at 3600', turbulent.
1649:41 Reach mixed layer top at about 2200'.
1652:30 - 1722:30 CCW circle at 500'. Still dark.
1722:30 - 1727:30 5 minutes more sampling at 500'.
Climb up to 1500', back to the drifted starting
point of the first circle.
1735:23 - 1805:23 CW circle at 1500'. More light. Scattered cu above.
Cu base flat.
Climb up to 1900'.
1808:34 - 1838:34 CCW circle at 1900'. About 20% cloud cover.
Still clearer inside the circle than the surroundings.
Descend down to 100'.
1830:00 Approximate time for sunrise.
1841:42 - 1911:42 CW circle at 100'.
1918:00 - 1948:00 CW circle at 6000'. BL top has grown to about 5000'.
Into cu tops occasionally.
1947:18 - 1957:18 porporsing at BL top.
2001:20 - 2011:20 Lidar leg at 10,000'. Heading is 20 degree for radiation
measurement and satellite intercomparison.
2011:21 - 2012:20 Extend the lidar leg at 10,000', roll
angle at 10 degree.
2012:21 - 2013:20 Same as above, except roll angle at -10 degree.
2013:21 - 2028:50 Looking for new clear area to start new set of circles.
2028:51 - 2034:55 Descend at 1000 fpm.
2034:56 - 2042:10 Descend at 500 fpm in BL. BL top is 4500'.
Decoupling layer between 1900' and 2300'.
2042:18 - 2112:18 CCW circle at 100'. Cloud above at the north end
of the circle. Clearer in the circle.
BL top about 1.3 km in clear region, about 1.6 km
in broken cloud region.
Climb up to 500'.
2115:27 - 2145:27 CW circle at 500'. Mostly clear, some clouds.
Climb up to 1500'.
2148:19 - 2218:19 CCW circle at 1500'.
Climb up to 3000'.
2020:53 - 2042:30 Incomplete CW circle at 3000'. Save time for
one more circle at 100' for obtaining time derivative.
The 3000' circle ended at -42.34S, 141.37E.
2246:10 - 2316:10 CW circle at 100'. Clear most of the time.
2316:11 - 2327:53 Ascend at 500fpm inside BL.
2327:54 - 2335:38 Ascend at 1000 fpm to ferry level (16,000').
0014:10 Descent has reached 8700'.
0022:00 Landed Hobart.
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The purpose of this flight was to sample clear air photo-chemistry across sunrise. There two stacks of measurements during this flight. The first one started in clear air. Clouds developed so rapidly that we start to see low level clouds at the time of the second circle. Boundary layer depth also grew significantly, from about 2200' in the early clear region to about 4500' at the end of the first stack. The maximum cloud cover was around 20\%. This development of the boundary layer and the cloud was associated gravity wave propagation in the measurement area.
The second stack of measurements was made mainly in clear air, with some cloud cover at the north end of the circle. Again the boundary layer was deep in cloud region and shallow in clear region. The clear air appeared to be hazy.
The second set of circles were about 0.5$^o$ longitude west of the first one. So, the measurements of the second stack was not in the same air mass as in the first one.
Five circles of measurements were made during the first stack, four within the boundary layer and one above. However, since the boundary layer grow very rapidly during the first stack, the 1900' circle may not be in the upper boundary layer at the time of measurements.
A porporsing leg across the circle was made after the first stack, followed by a lidar leg at 10,000'. This 10 minute lidar leg was designed with a heading of 20 degree while going across the circle for the purpose of radiation measurements and intercomparison with satellite measurements. At the end of the lidar leg, 2 additional minute of measurements were made with a 10 degree and a -10 degree roll angle in each minute.
There are five circles of measurement made in the second stack, two of which were at 100' in order to obtain time derivatives of variables. The measurements at 2500' was cut short to 2/3 of a circle to save time for the second 100' circle. No measurements in the upper mixed layer were made. The 2500' circle was at the top of the decoupled transition layer right below the cloud base when there was cloud.
Three complete soundings from 10,000' down to 100' were made during this flight. Slow ascent or descent (500 fpm) were used for measurements inside the boundary layer.