NSF C-130 Mission Summary Report (EPIC)

RF11 - 25 September 95 W Transect

Mission Summary - This flight featured a highly suppressed ITCZ at the
longitude of 95 W relative to previous 95 W transect mission.  The conditions
encountered included the following aspects: relatively weak SSW to SW winds
in vicinity and just south of the ITCZ (especially relative to 23 Sept.),
relatively low humidity just above the BL south of the ITCZ, weak winds over
the SST front, and the SST front south of its position on 23 September.
As on 23 September, while it was hazy at 1 S, there was no drizzle or sea fog.
There was an interesting lack of BL clouds between roughly 4.7 and 3.2 deg.
N.  In an overall sense, the relative vorticity (as gauged by the meridional
gradient in the zonal wind) was anomalously negative.  This aspect is
consistent with the 850 mb vorticity analysis done by U. Wisc. based
on satellite-derived cloud motions.  The dropsonde data collection was
largely successful, with some noisy data near 3 N, and missing low-level
data at 12 N.  The ocean probe deployments were spectacularly successful
with all probes turning on and reporting reasonable data (one BT did have
a wire break at 40 m depth).

Flight Notes

1333	Take Off (WSW winds above 1.5 km on ascent)
1352	Lat 14.7, 13,500', Thick Ci at 5.5 km
1405	Lat 13.8, In cloud
1408	Lat 13.6, widely scattered BL Cu, a few small cells with precip
	popping up in distance, quiet sea state
1415	Start of descent, patchy Ci OVHD between 5.5 and 6.5 km
1427	Lat 12.4, start of 100', widely scattered BL Cu at 500-700 and
	700-1000 m levels, BKN Ci OVHD, SST 28.7, TA 28.1, Wind 270 @ 4 m/s,
	thetae 352, q 18
1432	Spotted 12 N buoy, virtually no turbulence
1434	Began ascent, diffuse cloud bases at 500 m
1439	Lat 11.6, start of 5000', SCT BL Cu below, OVC OVHD at 4.5 km,
	wind 60 @ 3 m/s, thetae 342, q 12
1449	Lat 11.0, start of descent
1452	Lat 10.8, cloud tops near 600 m, relatively little turb. on
	descent, a bit drier than previous profile
1455	Lat 10.6, start of 100', SST 29.4, TA 28.7, wind 250 @ 6 m/s,
	thetae 350, q 16, clouds in the 600-800 m layer
1507	Flew past R/V Brown, a very few minor whitecaps
1508	Lat 10.0, began ascent, cloud base near 550 m, tops 800-1000 m
1514	Lat. 9.5, near start of 5000', wind 015 @ 6 m/s, thetae 340, q 10
1522	SCT-BKN patches of thick BL Sc
1524	lat 8.9, began descent, hit clouds around 900 m until 400-500 m
1529	Lat 8.6, began 100', some whitecaps, wind 230 @ 7 m/s, SST 29.5,
	TA 28.1, thetae 351, q 16, LGT Chop
1539	Lat 8.0, began ascent
1543	BT (good until 40 m)
1546	Lat 7.7, start of 5000', CP (good), wind 50 @ 5 m/s, thetae 341
	q 10
1548	CTD (good)
1554	Lat 7.2 N, start of descent, BT (Good), some towering Cu, Ci at
	8.5 km, cloud tops between 700 and 1000 m
1600	Lat 6.9, start of 100', very light chop, SST 28.0, TA 27.3,
	thetae 347, q 14, wind 205 @ 6, minor whitecapping, a few
	clouds between 500-700 m, more continuous cover 1.2-1.4 km
1606	Lat 6.5, began ascent
1608	BT (good), in cloud 800-1000 m, SCT BL Cu below BKN-OVC Ci
1612	Lat 6.2, start of 5000', CP (good), wind 70 @ 6 m/s, thetae 343
	q 12, Ci at 5.3 km in patches
1614	CTD (good)
1620	Lat 5.7, start of descent, BT (good), wind minimum at 1000 m
	of 135 @ 2 m/s, cloud tops 700 m
1626	5.3 N, start of 100', light chop, some whitecapping, wind 210 @ 7,
	SST 27.6, TA 26.5, thetae 344, q 14, Cu & Sc 500-700 and 500-1000 m
1631	Spotted 5 N buoy
1632	Lat 5N, begain ascent BL clouds 500-800 m
1634	BT (good)
1638	Lat 4.7, start of 5000', CP (good), partial coverage of Ci,
	wind 80 @ 7 m/s, thetae 337, q 8
1640	CTD (good), very few BL Cu below
1645	Lat 4.2, start of descent, virtually no BL clouds below, some
	Ci OVHD, BL top around 500 m (shallower than where BL clouds)
1652	Lat 3.9, start of 100', some whitecaps, wind 180 @ 7, light chop,
	SST 27.3, TA 25.8, thetae 338, q 12-13
1656	Spotted 3.6 N buoy, lots of birds
1657	Lat 3.6, start ascent, still no BL clouds
1700	BT (good), BL top near 600 m, diffuse TWI
1703	Lat 3.3, start of 5000', CP (good), just starting to go over
	a few SCT BL clouds, wind 105 @ 3, thetae 332, q 7
1705	CTD (good), very thin Ci (not evident from SABL)
1708	Lat 3.0, moved over solid undercast of BL stratus
1712	Lat 2.8, start of descent, BL (good), cloud top near 1000 m,
	sharper capping inversion, encountered clouds between 720
	and 450 m
1719	Lat 2.4, start of 100', BKN-OVC Sc and stratus above but still
	a bright sky, SST 26.1, TA 24.2, thetae 334, q 11, no
	whitecaps, LGT chop, wind 145 @ 4 m/s
1723	Lat 2.2, a little darker, continuous OVC
1725	Lat 2.0, start ascent, BL stratus and Sc between 800 and 1000 m
1728	BT (good), into cloud at 750 m, top at 1400 m, sharp, thin TWI
1731	Lat 1.7, start of 5000', CP (good), wind 100 @ 6, thetae 331,
	q 7, no Ci or other clouds above BL
1733	Lat 1.6, CTD (good)
1741	Lat 1.2, start descent, BT (good), uniform stratus below, hit
	cloud/BL top near 1000 m, main base near 750 m, patches of cloud
	between 400 and 700 m
1747	Lat 0.9 N, start of 100', a bit more turbulence than previous
	100' leg, SST 24.0, TA 22.0, minor whitecaps, wind 140 @ 7-8,
	thetae 330, q 10
1752	Some minor breaks in OVC
1753	Lat 0.5, SST 23.1 (not as much of a drop as on previous flight)
1755	Lat 0.5, near start of 100' E-W leg, some breaks in OVC, light
	chop, SST 23.0, TA 21.4
1757	Near end of E-W leg, SST 23.6, TA 21.3
1758	Lat 0.5, start ascent
1801	Lat 0.4, BT (good), encountered cloud at 700 m up (top 800 m)
1806	CTD (good), some variability in clouds from above, no clouds
	above BL
1808	Lat 0.0, 5000', wind 125 @ 5, thetae 331, q 7, distinct line
	on water
1812	0.2 S, begin descent, BT (good), clouds between 650 and 800 m
1818	0.6 S, start of 100' N-S leg, hazy but no sign of sea fog,
	breaks in OVC (especially in middle of leg), very little
	turb., SST 19.5, TA 20.5, Ophir 18.4, wind 135 @ 6-7 m/s,
	thetae 327, q 10-11
1827	Lat 1.0 S, start of 100' E-W leg, SST 19.8, TA 20.6, wind 140 @ 5,
	thetae 328, q 11, continued hazy, clouds mostly 600-800 m,
	SABL indicates some lower bases
1830	1.0 S, begin final ascent, max wind near 700 m, cloud top near 1000 m
1915	Lat 2.2 N, uniform BL cloud tops at 600 m, flight-level winds
	20 @ 1-2 m/s
1926	Lat 3.1, CLR below
1943	Lat 4.4, SW-NE oriented BL roll clouds, flight-level wind 345 @ 7
2015	Dropsondes at 3 and 6 N repeated due to total and wind failure, resp.
2038	Lat 8.5, flight-level winds 030 @ 5 m/s, appears to be considerable
	fallout of ice crystals from Ci aloft
2125	Lat 12.3, passed through ITCZ with no precip, flight-level winds
	070 @ 6-7 m/s
2221	Landed