NSF C-130 Mission Summary Report (EPIC)

RF10 - 23 September 95 W Transect

Mission Summary - This flight featured a much more active ITCZ at the
longitude of 95 W than during previous 95 W transect missions.  Notable
differences with the previous 95 W missions also include the following aspects:
relatively lower (2-3 g/kg) humidity above the BL south of the ITCZ, the
SST front north than earlier (e.g., SST at 0.8-0.5 N was 23.5 to 21.5 on
this flight while 24.4 on 19 Sept), the cirrus at the ITCZ was much higher
and extnded considerably farther south, there was a lack of seafog or
drizzle in the vicinity of 1 S even though SST was quite cold.  The latter
aspect is probably related to the relatively dry BL found south of the
equator (1 g/kg smaller q).  The ocean probe launching was successful,
with 10/12 BT's, 4/6 CTD's, and 5/6 CP's returning reasonable data.

Flight Notes

1332	Take Off (winds 90 @ 17 m/s between 500-1000 m on ascent)
1356	Lat 14.5, 13,500', Mix if Ci, As/Ac and BL Sc clouds
1359	In cloud at edge of a Cb, LGT-MOD chop
1411	Lat 13.5, lots of BL Cu, Ci, Cs and some As
1418	Two As layers between 3.2 and 3.6 km
1421	CAT near 2.2 km; E winds below and S winds above
1426	Relatively strong winds on descent (120 @ 15 m/s at 800 m)
1429	Lat 12.4, start of 100', few BL clouds, considerable As,
	Cs, minor whitecapping, SST 29.2, TA 27.2, Wind 130 @ 8 m/s
1434	Spotted 12 N buoy (birds circling); something floating nearby
1438	BT (good)
1442	Lat 11.6, start of 5000', BL clouds below, thick OVC between
	3.5 and 4 km, wind 280 @ 1 m/s, thetae 345, q 12
1451	Brief light rain
1452	Start of descent
1458	In rain, low-level leg at 300' because of reduced VIS,
	SST 29.8, TA 28.1, wind 124 @ 3 m/s
1501	Briefly out of rain
1503	Lightning in the distance, SABL not seeing clouds above
	1-1.5 km presumably because of attenuation in rain
1509	Passed R/V Brown
1510	Begain ascent at 10 N, no sign of a BL or capping stable
	layer; at low-levels weak dry/moist stability/instability
1514	Lat 9.5, in moderate-heavy rain, LWC up to 1 g/m3, updrafts
	to 4 m/s downdrafts to -2 m/s
1522	Temporarily out of heavy rain
1524	Back in precip, but near S edge based on nose radar
1526	Lat 9.0, start of descent, near end of R/R-
1529	Ship spotted, some clouds up to 3 km
1531	At 100', whitecaps, noticeably bigger swell from the S than
	seen on previous flights, max wind on descent 210 @ 14 m/s
	at 500 m
1533	Lat 8.5, 100', SST 29.5, TA 28.5, wind 205 @ 11, thetae 354
	q 18
1535	In R- with low cloud bases for about 1 minute
1539	Back in R-, briefly
1542	Brighter sky, no precip in area
1543	Spotted 8 N buoy, birds OVHD
1545	Lat 7.9 N, began ascent to 5000'
1548	BT at 3000' (Dead)
1552	CP (Dead)
1553	CTD (Good)
1555	Lat 7.4 N, 5000', SCT-BKN BL Sc, OVC OVHD (not evident on SABL),
	wind 238 @ 6, thetae 347, q 13
1556	Replacement CP (Good to 750 m where wire apparently broke)
1600	Lat 7.2, began descent 
1605	Lat 6.8, 100', SST 27.8, TA 27.3, Wind 195 @ 12, thetae 347
	q 16, SABL indicates clouds between 0.5 and 1 km
1612	Beginning ascent at lat. 6.5 N
1614	BT (Good)
1618	Lat 6.2, 5000', CP (good)
1620	CTD (Good), 5000', above all BL clouds of Sc and Cu, mostly
	OVC w/ thin spots, wind 243 @ 2-3, thetae 341, q 11
1622	Clipped top of Cu
1626	Lat 5.7, BT (good), started descent, thin layer of cloud near
	1400 m
1629	Lat 5.5, Cu tops near 900 m, bases near 400 m
1632	Lat 5.4, start of 100' leg, SST 27.5, TA 26.2, wind 205 @ 11
	thetae 341, q 14, slightly fewer whitecaps
1636	Light drizzle in spots, apparently where clouds extend upwards
	to a stratus region near 1.5 km (based on SABL)
1639	Lat 5.0, began ascent to 5000'
1641	BT (Good), between cloud decks at 800 m, still OVC OVHD
1645	Lat 4.7, CP (good), start of 5000' leg, thin OVC OVHD, above
	all BL clouds, wind 205 @ 5, thetae 340, q 10
1647	CTD (bad; turned on but no data)
1653	Lat 4.2, began descent, BT (good), still thin Ci OVHD, no As,
	BL cloud tops at 1100 m, bases near 550 m
1659	Lat 3.9 N, start of 100' leg, OVC w/ stratus and Sc, SST 27.3
	TA 25.1, wind 200 @ 9 m/s, thetae 338, q 13, smaller and fewer
	whitecaps
1704	Spotted 3.6 N buoy, some very light, brief drizzle
1709	Lat 3.4, BT (Bad), cloud tops 1050-1100 m, SCT Ci OVHD
1712	Lat 3.2, 5000', CP (bad), over very uniform BL stratus,
	better defined TWI on ascent, wind 142 @ 7, thetae 339
	q 9.5
1714	CTD (good)
1721	Lat 2.8, began decent, BT (good)
1723	Lat 2.6, cloud top 1000 m, base between 500-700 m
1728	Lat 2.4, level at 100', LGT chop still some whitecaps, wind
	180 @ 9, thetae 332 q 11
1735	Lat 2.1, starting ascent, breaks in OVC
1737	BT (good), BL clouds below 900 m, looks like more variability
	in BL cloud deck, still patches of thin Ci OVHD
1740	Lat 1.7, start of 5000', CP (good to 1300 m), sizable holes
	in undercast, wind 145 @ 10, theta 336, q 8.5
1742	CTD (good but noisy below 400 m), running 7 min. behind previous
	flight
1751	Lat 1.2, beginning descent, BT (good), cloud top at 700 m, base
	near 500 m, relatively thick TWI
1757	0.8 N, start of 100' N-S leg, SABL shows BKN deck with 400-500
	m base and 700 m top, still some whitecaps, wind 165 @ 9 m/s
	thetae 328, q, 10, SST 23.8, TA 21.6
1803	Striking drop in SST along N-S leg, SST 21.7 near 0.5 N
1804	Lat 0.5, start of 100' E-W leg, continuous OVC of stratus
	and Sc between 400 and 700 m, LGT chop, SST 21.5, TA 21.1
	wind 155 @ 8
1808	Near end of E-W leg SST 21.0, TA 20.7, start ascent, tops 700 m
1811	BT (good), no clouds above BL
1814	Lat 0.1 N, level at 5000', wind 160 @ 8, thetae 332, q 7
1816	CTD (good), unifrom undercast, more southerly and drier than
	previous flight of 19 Sept.
1823	Lat. 0.2 S, began descent, cloud top near 700 m, diffuse base
	near 600 m, max wind near 6-700 m level.
1828	Lat 0.6 S, start of 100' N-S leg, a few monor whitecaps and
	less swell, no sign of drizzle or very low cloud bases, wind
	155 @ 6, SST 19, TA 20.5 (Ophir 18.9), thetae 328, q 10, some
	breaks in OVC
1836	Beginning to get hazy near lat 1 S.
1838	Lat 1 S, 100' E-W leg, SST 19.4, TA 20.7, wind 160 @ 5,
	hazy, continuous OVC on E-W leg
1841	Lat 1 S, start of ascent, max wind on ascent 140 @ 8 near 500-700
	m, cleared tops near 700 m
1857	1st dropsonde at about .2 N (good), from SABL there appears
	to be a decrease in BL height/cloud top of 300 m in 15-20 km
	just north of the equator
2043	Lat 8.3, flight level wind 265 @ 7, AC/As 2.7-3.2 km
2047	Lat 8.7, approaching continuous line of mod-heavy precip about 120 km
	wide in N-S extent
2054	Lat 9.3, diverted to avoid heaviest precip, in large downdrafts
	(-3 to -5 m/s) for about 10 minutes!  Must be an offset
2122	Lat 11.4, flight level winds 270 @ 6
2130	Lat 12 N, Penetrative Cu w/ detrainment from something like
	the 4-5 km level, with a few much bigger, deeper cells in distance
2233	Landed in worsening VIS, CIG conditions