NSF C-130 Mission Summary Report (EPIC)

Flight 9 
ITCZ Flight 6
Plan for today will be to go directly to 10N, 97W at 4000 m and work
from the east to the west finding clouds in different stages of development.
145800	Take Off
151600	Current conditions are severe clear but on the ascent out of Huatulco we found a heavy haze layer between 1000 and 3000 m with peak concentrations in CN, PCASP, FSSP-300 and FSSP-100 at an altitude of about 1800 m.
154155	As we go south there is a lot of variation in mixing ratio, by
	factors of 2 or more. We are seeing a lot of different cloud formations, towering Cu, 	mid-level trade Cu and low level cumululus humulus
	Lidar is showing clouds at the top of the BL at about 400 m and
	another layer at 2.5 Km.
	We have been going through a number of haze layers at this altitude
	as seen by the CN in some places, increased FSSP-300 in others.
160500	We have found a good line of developing clouds in an E-W orientation
	that we just passed over and are turning around to make a W->E
	track along the line at 4000 m. This is at around 11N, so we stopped
	short of our original target point.
161105	Cloud Photo 1 and Cloud pass
161645	Passed through the edge of a growing turret
161745	Descending to 2.5 Km and we are going to run back up the line until
	we make a left turn to go across the line
162145	Starting our pass along the line at 2.5 Km
162300	Passing through clouds
162630	Cloud Photo 2
162707	Cloud pass
163400	We are now getting ready to cross across the line at 2500 m
163645	Cloud Pass
164000	Coming around and descending to 1000 m to go back across the line
164400	Starting crosswind leg going south at 1000 m
164430	Cloud pass
165200	Turning 135 left to go back to the cloud for an along cloud track
	We will be going in and ot of clouds that are growing.
170140	Heading along the line
1703	Cloud photo 3
170400	Cloud passes
170945	Turning and descending to 300 m and going to try and find cloud base
171224	Probably just above cloud bases. No drizzle, droplet concentrations 
	variable but comparable to PCASP concentrations
171745	Cloud bases are now above us.
1732	Turning and descending to 30 m, cross track
1740	Turning left to find the line and proceed at 30 m down the line
174700	Turning north to start a sounding
1750	Start of sounding
180400	A number of pronounced aerosol layers during this sounding, some
	that are clearly correlated with wind velocity maximums
181000	End of sounding, descending to 4000 m
185400	We have been heading south and are now approaching the largest cloud
	in a very weak cloud line
1856	Cloud Pass
1857	Descending to 2500 m and turning back to croos line going north
1901	Heading north at 2500 m
1902	Entering clouds
190825	into cloud
191120	Cloud Photo 4
191245	Cloud Pass
191320	Cloud Pass
191800	Descending to 1000 m on north side of line of clouds, turning to the
	south to go back across the cloud line
192230	Headed south and passing through cloud
	Winds are now from NW. At higher altitudes they were from NE
193820	Starting through a whole series of cells with good updraft (5)
	and modest FSSP concentrations.
194500	Now at 300 m, just above cloud bases
195600	Passing right under cloud base
200800	Last pass across clouds at 30 m
201100	FSSP showing parrticles out to 30 um
201300	High CN counts
2027	Lidar shows a beautiful picture of rain falling from stratus deck at
	2500 m
202900	Starting of sounding to the south
204700	End of sounding
205845	Going through an ice crystal cloud with rimed columns
210000	Starting down to do a down sounding
	Good aerosol layer at 2500 m. We saw this in earlier sounding.
211700	End of sounding
	Ascending to 2500 m where we will ferry home. This appears to be a
	strong aerosol layer where we should see interesting CCN
Summary
Today's flight looked at cloud development in the northwest sector and southwest
sector of the research region. The clouds in both regions followed E-W lines
with the northern most line being better developed in terms of length and
vertical extent of the towers that formed.

The north line was measured with cloudpasses at 6000, 4000, 2500, 1000, 300 and
30 m legs that went both across the line and along the line, avoiding the
western portion of the line with high reflectivity regions. The cloud line
was approximately parallel with the average wind vector that was from the east
at 6-8 m/s. After finishing the 30 m leg along the line we did a sounding to
6000 m that began towards the north then turned to the south at 2500 m. Once
at 6000 m we descended again to 4000 m and proceeded south along the 96W
meridian. We maintained this altitude and heading until encountering another
E-W cloudline at approximately 8.5N.

The second cloud line was much less organized than the northern cloud line with
fewer clouds in the line. We decided to make measurements only across the line
but at the same altitudes that we measured the first line except for 6000 m.
All of the legs were made between 8 and 9 degrees N.

We started our passes at 4000 m, heading south and went through three growing
towers. After that each of the passes at successively lower altitudes went
through cloud. The width of the cloud was progressively wider as we went down
in altitude. After the final 30 m leg, we did a sounding to 6000 m, starting
south then turning north at 2500 m to finish the sounding.

After reaching 9 N, we did one more sounding down to the surface then back up
to 2500 m where we ferried home. The 2500 m altitude was selected as this is
where we encountered a pronounced aerosol layer during the previous sounding
and we wanted to characterize this layer with our aerosol instrumentation.

Note: The lidar data will provide excellent characterization of these cloud
structures as the IR channels appears to be able to see through most of the
smaller clouds.