NSF C-130 Mission Summary Report (EPIC)

10 October 2001 - 95W Transect

Mission Summary - This flight represented both the last 95W transect and the
last research flight of EPIC2001.  The weather during this flight included
rather suppressed convection in the ITCZ during the outbound leg and more-or
less typical convection in the ITCZ during the inbound leg, when a few 
vigorous appearing cells were seen from along 95 W.  The ABL southerlies
were much weaker than normal south of the ITCZ, especially in the southern
part of the domain.  The observed winds here were something like 150 @ 4 m/s
versus more typically 160 @ 9 m/s.  The ABL wind max of 7.5 m/s in the vicinity
of the equator was one-half that found a week earlier.  There was also a
lack of any return-type northerly flow above the ABL in this region.  The SST
front was not as strong as had been encountered before and its gradient was
concentrated near the equator.  For example, the SST at 0.9N was 25.2 C and at
1.0S was 20.0 C.  The SST at 0.5 N was a remarkable 2 C warmer on this day
than on the day before.  There were essentially no high clouds over the ABL
south of 5-7 N.  The change in the clouds across the SST front was of the
usual nature, with fairly uniform stratocumulus clouds north of the SST
front changing to patchy stratus clouds over the cold tongue.  Extra BT's
were again deployed in the vicinity of the equator and hopefully, can
help indicate how the SST's of that region evolved so rapidly.  The success
rates of these probes were 16/19 for the BT's, 7/8 for the CTD's and 6/8
for the CP's.  The dropsondes data looks good, with the possible exception
of some wind dropouts from the sonde at 4 N.

Flight Notes

1433	Takeoff
1445	Some whitecaps near shore
1530	Lat 12.4, start of 100', SST 29.7, TA 29.5, wind 150 @ 2 m/s
	sea lightly rippled, thetae 359, q 19, very light turbulence,
	Cu congestus west of track
1536	Lat 12.0, start ascent
1538	Lat 11.9, BT (good), mostly CLR above
1542	Lat 11.6, CP (good)
1545	Lat 11.5, CTD (good), at edge of cloud, wind 125 @ 8, thetae 345
	q 13, isolated moderate cless in area
1553	Lat 11.0, start descent, BT (good), in CLR air but headed for
	cloud cluster
1556	Lat 10.8, cloud tops and base about 720 m and 400-500 m, hazy
1559	Lat 10.6, start of 100', rippled sea, wind 196 @ 3, thetae 357, 
	q 18-19, SST 29.5, TA 29.3, very light turb, some swell, vigorous-
	looking cells (but no anvils) to west of track, mostly CLR OVHD
1609	Lat 10.0, TAO buoy spotted, picking up some minor whitecaps
1610	Lat 9.9, start ascent, thin clouds 400-500 m
1613	Lat 9.8, BT (bad)
1617	Lat 9.6, CP (good to 800 m), 5000', wind 215 @ 3, thetae 346, q 13
	CLR above
1619	Lat 9.4, CTD (good), CLR above
1627	Lat 8.9, start descent, BT (good), some wispy clouds at 1.3 km, SABL
	shows patches of As at 2 km
1633	Lat 8.6, start of 100', grayer sky, wind 285 @ 4-5, SST 29.2, TA 27.8
	thetae 355, q 18
1635	Lat 8.5, light rain/drizzle, rougher sea than on previous 100' leg
	but still no whitecaps
1637	Lat 8.4, wind 245 @ 7 m/s, now getting some whitecaps, light chop,
	Mess of clouds below 2 km from SABL (lowest bases near 400 m)
1642	Spotted 8 N buoy
1643	Lat 8.0, start ascent, a little drizzle
1647	Lat 7.8, BT (good)
1649	Lat 7.6, start of 5000', CP (good), in cloud, thetae 354, q 16,
	wind 250 @ 6
1651	Lat 7.6, CTD (good), skimming in and out of irregular cloud tops
	CLR above, some Cu topped by pileus
1657	Lat 7.2, start descent, BT (bad)
1658	Entered SCT-BKN Sc (tops near 1200 m)
1700	Lat 7.0, replacement BT (bad), weak wind max near 400 m (240 @ 10)
1703	Lat 6.8, start of 100', some whitecaps, CLR OVHD temporarily, light
	chop, wind 235 @ 9-10, SST 28.0, TA 27.9, thetae 351, q 18
1706	Lat 6.7, now SCT BL SC & Cu between 400-700 m with some extending
	to 1 km, whitecaps
1709	Lat 6.5, start ascent, two decks 400-700 and 800-1000 m
1711	Lat 6.4, BT (good)
1714	Lat 6.2, start of 5000', CP (bad), CLR above, hummocks in undercast,
	wind 285 @ 5, thetae 345, q 13
1716	Lat 6.1, CTD (bad)
1719	Lat 5.9, replacement CP (good), some thin Stratus at 2 km
1722	Lat 5.7, start descent, BT (good), some cloud tops at 1200 m others
	at 800 m, looks like Cu feeding stratus, hitting clouds itermittently
	during descent, bases near 300 m
1727	Lat 5.4, start of 100', whitecaps, light chop, SST 27.7, TA 26.8
	wind 220 @ 9 m/s, thetae 348, q 16, clouds 400-700 m and 800-1100 m
1733	Lat 5.0, start ascent, wisps of Ci OVHD, some clouds 400-800, 950-1400 m
1736	Lat 4.9 BT, (good)
1740	Lat 4.7, start of 5000', CP (good), wind 310 @ 1-2, thetae 344, q 13
1741	Lat 4.6, CTD (good), cloud top height uniform, CLR OVHD
1746	Lat 4.2, start descent, BT (good), some tops near 1350 m, moderate chop
	in cloud during descent, most clouds between 450 and 800 m, well-mixed
	southerlies to cloud base
1752	Lat 3.9, start of 100', SST 27.4, TA 26.3, wind 210 @ 8, thetae 342, q 15
	light chop, SCT-BKN Sc between 500-800 m
1757	Spotted 3.6 N buoy, numerous birds
1758	Lat 3.6, start ascent, SCT BL cloud bases near 400 m, some clouds only
	100 m thick, most tops to 110 m
1800	Lat 3.4, BT (bad)
1804	Lat 3.2, start of 5000', CP (good), 125 @ 6 m/s, thetae 339, q 10,
	mix of BL Cu and Sc below, almost completely clear above (a few minor
	wisps of Ci
1806	Lat 3.1, CTD (good)
1812	Lat 2.8, start descent, BT (good) main clouds 800-1000 m and 400-600 m
1818 Lat 2.4, start of 100', SST 26.3, TA 24.5, wind 190 @ 6, light chop
	minor whitecaps, thetae 337, q 15, fairly thick OVC, looks as if light
	drizzle is falling in the vicinity
1827	Lat 2.0, start ascent, fairly uniform overcast bases 500 and 700 m
	uniform tops near 1000 m, CLR above
1829	Lat 1.8, BT (good)
1833	Lat 1.6, CP (bad)
1835	Lat 1.5, CTD (good), at 5000', wind 090 @ 7, thetae 341, q 11
1840	Lat 1.2, start descent, BT (good), tops 1050 m, diffuse base 450-400 m
1846	Lat 0.9, start of 100', SST 25.2, TA 23.0, wind 185 @ 5 m/s, rippled
	sea, light chop, thetae 330, q 12, SABL: 500-700 m bases, 750-900 m tops
1850	Lat 0.6, thin spots in OVC quickly becoming breaks
1852	Lat 0.5 , turn for E-W leg, SABL: stratus/Sc between 650-850 m
1854	Lat 0.5, start of 0.5 N E-W leg, SST 23.2, mostly OVC, wind 150 @ 4
1858	Lat 0.5, start ascent, diffuse cloud base near 400 m, uniform tops
	near 850 m
1901	Lat 0.3, BT (good), very little speed shear on ascent, no northerlies
	above BL
1905	Lat 0.1, CTD (good), patches of stratus underneath
1909	Lat -0.1, BT (good)
1912	Lat -0.3, start descent, BT (good), cloud top 650-700 m, diffuse base
	near 500 m, wind max at 550 m (150 @ 7 m/s)
1917	Lat -0.6, start of 100' N-S leg, SST 20.4, TA 21.4, wind 150 @ 4 m/s
	thetae 330, q 13, some thin spots and breaks in OVC
1925	Lat -1.0, start of 100' E-W leg, SST 20.0, TA 21.6, wind 150 @ 3,
	thetae 329, q 13
1931	Lat -1.0, start ascent for inbound ferry, cloud tops near 750 m
1932	Lat -0.9, BT (good)
1935	Lat -0.8, CTD (good)
1938	Lat -0.7, BT (good)
1940	Lat -0.5, holes in stratus undercast
2000	Lat 0.9, flight-level wind 240 @ 10
2100	Sondes at 4 and 4.3 N with marginal winds
2105	Lat 6.0, marked decrease in O3 and increase in humidity
2313	Landed