DC-8 09/21/13 - 09/22/13

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Flight Number: 
Payload Configuration: 
Nav Data Collected: 
Total Flight Time: 
9.1 hours
Flight Segments: 
Start:09/21/13 17:05 Z Finish:09/22/13 02:10 Z
Flight Time:9.1 hours
Log Number:138301PI:Kent Shiffer
Funding Source:Hal Maring - NASA - SMD - ESD Radiation Science Program
Purpose of Flight:Science
Comments:The Houston ship channel objective had to be canceled due to ceilings below 900 ft AGL. Flight proceeded to a point near the Georgia, Florida, Alabama border and turned north arriving just on the leading edge of a large cold front near Madison, GA. A wall step climb was conducted from 1300 ft AGL to FL390 back and forth between Madison and Charlotte, NC. ATC advised of a citizen telephone alerts approaching Charlotte and recommended notifying the FAA Domestic Events Network prior to future similar flights. Following the “wall” sampling the flight proceeded to resample the eastern Ozarks area centered at Dexter, Missouri. Flight recovered at Ellington with no instrument of aircraft discrepancies.
Flight Hour Summary: 
Flight Hours Approved in SOFRS187
Total Used180.6
Total Remaining6.4
138301 Flight Reports
Date Flt # Purpose of Flight Duration Running Total Hours Remaining Miles Flown
08/02/13 - 08/03/13130602Check4.15.9181.1
08/06/13 - 08/07/13130604Science8.719.6167.4
08/08/13 - 08/09/13130605Science7.827.4159.6
08/26/13 - 08/27/13130612Science7.782.6104.4
08/27/13 - 08/28/13130613Science8.791.395.7
08/30/13 - 08/31/13130614Science7.999.287.8
09/21/13 - 09/22/13130623Science9.1173.113.9
09/23/13 - 09/24/13130624Transit7.5180.66.4

Flight Reports began being entered into this system as of 2012 flights. If there were flights flown under an earlier log number the flight reports are not available online.

Related Science Report: 

SEAC4RS - DC-8 09/21/13 - 09/22/13 Science Report

Mission Summary: 



For the final EFD to EFD sortie of SEAC4RS the DC-8 had 3 planned objectives: 1) make a low level pass just downwind of the sources in the Houston ship channel, 2) sample the inflow and outflow of  the cold front that extended from nearly overhead Houston across the SE and E coasts, and 3) sample smoke from agricultural fires in the MS valley.  The planned track to achieve objective 2 included a long BL run from SE MS all the way to SW NC to sample inflow (from Pts 1 to 2 to 3 on attached fight track) and then a wall across SC (between Pts 2 and 3) to sample outflow.


At the preflight Wx brief it was clear that the front had advanced more quickly  along the Gulf Coast than forecast and was sitting on top of Houston and coastal LA, MS and AL.  It was clear that the ship channel run would not be possible due to thick clouds just 900 feet above the surface, and that being in the BL directly under the front would be difficult, so the plan was changed to eliminate the first objective and to begin the BL run much further E, starting in S GA just N of Tallahassee.  Because these changes were expected to save time, a BL run over the Ozarks was added to the revised plan.


The inflow BL leg and outflow wall were both well located, just to the east of the front at the time DC-8 was in the region.  We did encounter quite a bit of rain while in the BL, but the concentrations of most of the tracers were comparable to what we have seen on previous flights in the SEUS.  The outflow wall included legs at 16, 21, 28 and 39 kft, with a complex mixture of warm, mixed phase, and cold clouds encountered along the 3 lower legs.  We were in a thick layer of cirrus (~ 32-44 kft) for the final leg.  Concentrations of BL tracers were not clearly enhanced except near Pt 2 on the 28 kft leg, APR2 reported convection beneath us at this point, suggesting that we sampled outflow from a single, growing cell. 


Final phase of working the front called for the DC-8 to cross through it, hoping to see UT gradients caused by the front.  We climbed to 40 kft in the thick cirrus layer and headed west, but at the same time there was discussion on the plane and with the nowcasters at EFD that the high cirrus was not the result of the front, which had convective tops much lower (22-30 kft).  It was decided that we should try to cross through the front at 24-25 kft rather just pass over it, so we descended to 24 kft as quickly as we could.  However, we did not get to desired altitude until we were west of the front so we reversed course and crossed the front twice, east bound back to Pt 3 and west bound toward Pt 4.  In the region where we crossed there was no active convection in the front, and no obvious enhancements in BL tracers.


DC-8 proceeded west bound at 24kft under thick cirrus and above solid BL cloud deck about ½ was across TN.  When we finally saw the sun some of the chemists woke up and pointed out that we were encountering stratospherically impacted air masses.  A little further west we began a descent to the BL to set up our pass through the Ozarks.  We began the triangular pass at 1000 ft AGL over farm land in the river valley and maintained that altitude most of the way to the NW point.  The sun was very close to setting when we began, when it grew dark we had to resume IFR and ascend to 3 kft.  Isoprene and products remained significant in the dark and possibly above the nocturnal BL.  As we approached the NE turn point we encountered major pollution plume with greatly enhanced NOx, this plume extended part way down the leg to S and starting point.  Reports on the plane indicate that this entire pass provided unique opportunity to observe night time isoprene chemistry over a wide range of NOx, and should be an important addition to our day time visits to the same region under different conditions.


After the Ozarks the DC-8 climbed to 40 kft and proceeded direct to EFD, landing after a 9.1 hour flight.  All instruments functioned well and are ready for transit to DAOF on 23 Sept.


Planned and actual flight tracks