HU-25C Guardian 09/23/15

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Flight Number: 
OIB2015 Arctic North Central Gap 02
Payload Configuration: 
Nav Data Collected: 
Total Flight Time: 
3.9 hours
Flight Segments: 
Start:09/23/15 11:43 Z Finish:09/23/15 15:39 Z
Flight Time:3.9 hours
Log Number:15F005PI:John Woods
Funding Source:Thomas Wagner - NASA - SMD - ESD Cryospheric Science
Purpose of Flight:Science
Comments:The HU-25 completed its first OIB Arctic science data mission out of Thule, Greenland today. Aircraft and science instruments performed well. Next data flight scheduled for Thursday, September 23.
Flight Hour Summary: 
Flight Hours Approved in SOFRS100
Flight Hours Previously Approved 67.4
Total Used32.665.3
Total Remaining 2.1
16F002 Flight Reports
Date Flt # Purpose of Flight Duration Running Total Hours Remaining Miles Flown
10/05/15OIB2015 Arctic Sea Ice CentralScience3.63.663.8
10/05/15OIB2015 Arctic Sea Ice EastScience3.87.460
10/06/15OIB2015 Arctic Ice-Sat2 NorthScience411.456
10/07/15OIB2015 Arctic Transit Thule to KangerlussuaqTransit213.454
10/08/15OIB2015 Arctic Southwest Coastal AScience3.817.250.2
10/08/15OIB2015 Arctic Thomas-Jakobshavn 01Science3.720.946.5
10/09/15OIB2015 Arctic Umanaq BScience3.924.842.6
10/13/15OIB2015 Arctic Jakobshavn Eqip StoreScience2.927.739.7
10/13/15OIB2015 Arctic Southeast Coastal AScience3.631.336.1
10/18/15OIB2015 Arctic Southeast Coastal BScience4.135.432
10/19/15OIB2015 Arctic Helheim-KangerdlugussuaqScience3.739.128.3
10/19/15OIB2015 Arctic Helheim-Kangerdlugussuaq Gap BScience3.94324.4
10/20/15OIB2015 Arctic Jakobshavn Mop-UpScience3.746.720.7
10/20/15OIB2015 Arctic Southwest Coastal BScience3.750.417
10/21/15OIB2015 Arctic Southwest Coastal CScience3.453.813.6
10/21/15OIB2015 Arctic K-EGIG-SummitScience3.757.59.9
10/22/15OIB2015 Arctic Mopup SouthScience259.57.9
10/22/15OIB2015 Arctic Ferry BGSF-CYYRFerry2.261.75.7
10/23/15OIB2015 Arctic Ferry CYYR-KRICFerry3.3652.4
10/23/15OIB2015 Arctic Ferry CYYR-KRICFerry0.365.32.1
15F005 Flight Reports
Date Flt # Purpose of Flight Duration Running Total Hours Remaining Miles Flown
09/15/15OIB #1Check2.72.797.3
09/20/15OIB #2, 3, 4Ferry2.75.494.6
09/21/15OIB #2, 3, 4Ferry2.37.792.3
09/21/15OIB #2, 3, 4Ferry29.790.3
09/23/15OIB2015 Arctic North Central Gap 02Science3.913.686.4
09/24/15OIB2015 Arctic Northwest Coastal AScience3.717.382.7
09/25/15OIB2015 Arctic Northwest Coastal BScience3.821.178.9
09/28/15OIB2015 Arctic Sea Ice WestScience3.724.875.2
09/30/15OIB2015 Arctic North Central Gap 01Science3.928.771.3
09/30/15OIB2015 Arctic Zachariae-79NScience3.932.667.4

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: 

OIB - HU-25C Guardian 09/23/15 Science Report

Mission Summary: 

Mission: North Central Gap 02 (priority: medium)

This mission is a modified version of the Spring 2015 mission of the same name. Its purpose is to capture the seasonal melt signal over central Greenland, and track that signal from low elevations on the Baffin Bay coast as far across the ice sheet as range allows, in this case across the ice divide and partway down the east side. We shortened the spring 2015 flight by removing the easternmost portions of the lines, and we also remove a coast-parallel transit line on the west plus a centerline of Rink Glacier, replacing them with direct transits.

Weather today was dominated by a strong high pressure system over north central Greenland, with weaker lows to the west and north of Thule.  The weak low to the north created clouds which obscured our sea ice targets in the Lincoln Sea and westward, at low and medium altitudes.  The strong high itself created an on-shore wind south and east of Thule, which in turn created a widespread area of ground fog from the orographic effect of the steeply rising terrain along the Melville Bay coast.  These conditions left the medium-priority North-Central Gap 02 flight as the only candidate mission with almost completely clear skies.  We encountered a medium-altitude stratus cloud near the southeastern corner of the survey which obscured all three science instruments for approximately five minutes or less, while the remainder of the science line was completely clear.

This was our first science mission with the Falcon aircraft, and among the first science missions flown with the ATM operating exclusively at high altitude.  As a result we took a conservative approach with altitude, starting the survey at 25,000' MSL and climbing to 30,000' MSL as topography of Greenland's west coast rose as we proceeded inland.  This resulted in sensor altitudes above the ground which hovered around 20,000' for the vast majority of the science line.  ATM operated well under those conditions, as did DMS. Evaluation of the infrared camera imagery is ongoing, but appeared to be at least reasonable in real-time.  The lower altitudes, however, also negatively impacted the Falcon's true airspeed, and hence the range (the aircraft performs best at approximately 35,000' MSL).  This forced us to remove the easternmost 150 km of the two data lines.

We did not see a recurrence of the fouling of the nadir window, which we saw previously on the Langley-based test flight.  Mitigation measures taken by the Langley maintenance team may have solved that problem.

We conducted a ramp pass at 10,000' AGL.

Data volumes:
DMS: 11.3 Gb
Narrow Swath ATM: 10 Gb
FLIR: 1 Gb

total data collection time: 1.7 hrs


Map of Falcon - North-Central Gap 02

Small glaciers along Greenland's Melville Bay coast