INDOEX C-130: FLIGHT 7, 28 February 1999 Objective: Ron Brown Comparison and Closure This mission was designed to provide for a comparison with the Ron Brown near 2N and 71E. This was preceded with a clear-air closure mission about 20mi south of the Ron Brown in a patch of clear air between cloud bands. The comparison with the Ron Brown was flown at 100ft and 1,400ft for two 10min legs. This was followed by climbs to high altitude to probe convective cloud outflow layers but no high ultrafine values were observed. A radiation run over stratus was tried but aborted due to variable cirrus above. We then flew north for a KCO fly-by before landing. Nominal takeoff 10:15 LST, Multilayer clouds near Male, winds NNE at about 7m/s UTC 05:23 Takeoff and climb to 14,000ft, light scatter low near surface ca. 10 Mm-1 near surface and 20Mm-1 at 550m. 05:30 Thin cloud layer at 7,000ft 05:33 Thin cloud layer at 9,200ft 05:35 Many Cu at 10,000ft (tops) (3.8N, 73E) 05:38 Two photos W and SW of Cu 05:40 Ultrafine particles at 12,500ft 05:41 Level at 14,000ft 05:52 Ship at 2 20'N, 71 32' E 06:04 Dropsonde (1st fails, second OK) 06:07 Start above cloud closure leg to WNW 2.27N, 71.88E; No cirrus but small Cu 06:13 Turn and reverse heading from 315 to 135deg. (2.575N, 71.093E) 06:16 Turn to SE at 15,000ft 06:23 Turn to NW at 15,000ft (2.199N, 71.38E) 06:25 Dropsonde launch 06:27 Turn and reverse to 315deg at 15,000ft 06:29 Digital pictures of area #56,57,58 06:38 Turn and descend for closure profile, Digital #59 06:40 Start Descent at 135 heading 06:50 End descent to 6,000ft and turn. 06:52 Continue descent to 100ft level 06:56 Scatter Peak @ 2,200ft near 30Mm-1. 06:59 End descent to 100ft at 2.6N, 71E 07:02 Start 100ft leg - smooth ocean - no waves 07:05 Nephelometer switch to 10um cut but it drops? 07:13 End leg and turn to 2.08N, 71.448 - continue at 100ft under small Cu 07:16 Start leg 2 at 100ft 07:21 Digital image #60 looking up at clouds 07:32 Circle up to 15,000ft 07:35 Level at 2,500ft just above cloud 07:52 Cu built up below but a little clearer here. Talk to Ron Brown 07:57 Climb to 6,000ft 08:06 Level at 6,000ft 08:11 In cloud at 2,500ft for descent to R/V Ron Brown. 08:18 Turn inot 100ft leg heading 50deg. 08:20 Start 10 min leg for intercomparison 08:28 Pass Ron Brown 08:31 End leg and circle to just below cloud near 1,400ft 08:36 Cross above Ron Brown (06:36:20) to SW 08:41 Clouds increasing and scattering is variable 08:44 Climb above cloud. Thin stratus near 09:00 Hit Cirrus outflow 09:07 Climb to try for higher Cirrus 09:21 In anvil aoutflow, no ultrafine observed 09:26 Near cloud outflow, no new particles 09:36 Start run over high stratus for Valero but cirrus is present above. 09:43 Level above stratus with Cirrus above 09:46 Terminate run - not suitable for radiation - turn back to Male 09:50 Very thin stratus looks like old outflow - try and fly it - no ultrafine. Descend to about 9,000ft just above pollution haze layer 10:02 Punch cumulus cloud tops 10:10 In cloud 10:12 Broken clouds and cirrus above 10:20 Air cleans up 10:30 Hit top of small cumulus 10:33 Drizzle, hot wire and gerber probes agree 10:42 Multilayer clouds 10:54 Descend to KCO from 9,000ft 10:59 Moving under clouds @ 2,000ft, scattering increases 11:03 Maneuver at 200ft to miss rain to north of KCO 11:06 Level at 100ft and starting run past KCO (5.12N, 73.4E) 11:09 Pass KCO (11:09:13) on west going south 11:14 Neph impactor on 10um cut 11:17 End and Climb to 6,000ft above small Cu, surface air cleaner than aloft 11:20 Start 10min leg at 5,000ft, little change in upper layer 11:25 Descend from 5,000ft, air cleaner yet (and drier above 2,000ft) on descent to Male 11:30 Significant gradient from Male to KCO LAND