DC-8 09/18/13

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Flight Number: 
Payload Configuration: 
Nav Data Collected: 
Total Flight Time: 
7.6 hours
Flight Segments: 
Start:09/18/13 14:05 Z Finish:09/18/13 21:41 Z
Flight Time:7.6 hours
Log Number:138301PI:Kent Shiffer
Funding Source:Hal Maring - NASA - SMD - ESD Radiation Science Program
Purpose of Flight:Science
Comments:Operated over northern Gulf sampling 2 large cumulous areas from boundary layer to cloud tops. Proceeded to East Texas for fracking and oil well to sample boundary layer and then proceeded to work large convection system. Sampled both ocean and ground convection in coordination with the SPEC Lear jet and had successful coordination. Overall highly successful flight.
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 09/18/13 Science Report

Mission Summary: 



This sortie kept the DC-8 pretty close to Houston, but had a lot of objectives, and coordination with both the Lear jet and ER2 (see planned and actual flight tracks attached).  Plan called for us to head out over the Gulf and fly in the MBL in a region with a lot of drilling platforms, to constrain the character of air flowing into TX and possibly sample emissions from the platforms. We were then to join the Lear at a spot where the ER2 would fly a racetrack above while we worked marine convection.  Next target was continental convection over south TX, where a lot of fracking is occurring.  First inland task was to work convection, again in coordination with Lear and ER2 and then descend to BL to sample any emissions from the many sites fracking and producing petrochemicals.  We then planned to return to Houston and fly a DIAL/HSRL over the city from SSE to NNE.  Final objective was to fly a boundary layer pattern designed to intercept the plume from the Houston ship channel at different distances (ages) downwind.


All of the objectives were met, and the coordination of multiple aircraft was highly successful.  During our MBL run at 500 ft we observed quite a few spikes in combustion emissions, probably from ships and the drilling platforms, but no strong emissions of HC.  Post flight analysis did reveal some encounters with HC plumes, but these were modest (perhaps we were still above the BL?).  Lear arrived at the planned rendezvous point before us and found few clouds and no convection, but saw building towers further to the west.  Lear selected a cluster of cells and began making penetrations as we arrived at the new location to make passes just above and below cloud base. ER2 made adjustments and set up a racetrack over the same group of clouds.  DC-8.  DC-8 then spiraled up next to the clouds, observing them with APR2 on the near side of each circle, and then made several passes through and above the center of the cell.  Lear jet departed this region before the DC-8 to refuel and rejoin us at the next target region in south Texas, we transited at high altitude and remained high to look for candidate cells.  At the planned meeting point we observed candidate cells, but flew length of planned track to see if other storms looked better.  Turned out that the cells near NE end of the line were most promising so we returned there and began working cloud tops.  This location was very near to planned ER2 race track so they joined us overhead very quickly.  The Lear arrived and made penetrations at several levels beneath the DC-8.  At the end of the convection study the DC-8 descended to BL for 5 minutes and also made passes just below and 1000 feet above cloud base.  Emissions from the petrochemical operations in this area were observed in the tops of the cells we penetrated and nearby at altitudes between 33 and 37 kft.


To characterize emissions from the gas and oil extraction operations the DC-8 returned along the planned track to SW  at 1000 ft AGL.  We extended this BL leg to the NW into a region where more of the active drill sites were expected, then took a W to E path to rejoin original track.  Evidence of emissions from these operations was much stronger than we had earlier observed above the off shore platforms.


After the BL leg in S TX DC-8 climbed to 20 kft and transited to a point just S of Galveston to set up a DIAL/HSRL run across Houston.  At the N end of this leg we turned SW and ramped down to the BL to begin the pattern crossing the Houston  ship channel plume (see Fig 2).  This pattern successfully crossed the plume 3 times, and we were in the plume for 4th pass very near to sources when ATC  decided it would be a better idea if we got out of all the traffic and returned to EFD promptly.  It appears that this experiment worked out very nicely, with very high levels of NOx and alkenes, but low levels of O3, HCHO and other photochemically produced species close to the ship channel.  Further downwind the products increased as the NOx/NOy ratio decreased (Figures 3 and 4).  This short module has produced a rich data set that should help to better understand the sources of HCHO in Houston, and perhaps improve models ability to estimate O3 production.


DC-8 landed a little sooner than anticipated after 7.6 hour flight.  All instruments reported to be in fine shape through out the flight, ready for the next sortie.