Global Hawk #872 09/11/12 - 09/12/12

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Flight Number: 
Payload Configuration: 
HS3 - TN872 2012 config
Nav Data Collected: 
Total Flight Time: 
25.7 hours
Flight Segments: 
Start:09/11/12 11:06 Z Finish:09/12/12 12:48 Z
Flight Time:25.7 hours
Log Number:12H002PI:Marilyn Vasques
Funding Source:Hal Maring - NASA - SMD - ESD Radiation Science Program
Purpose of Flight:Science
Comments:The science target was Tropical Depression 14, which became Tropical Storm Nadine while TN872 was over the storm in the Atlantic. 35 sondes were deployed before the AVPS dispenser developed a problem, which was found after landing to be a jammed sonde in the launch tube. SHIS and CPL operated nominally.
Flight Hour Summary: 
Flight Hours Approved in SOFRS327
Flight Hours Previously Approved 178.1
Total Used148.946
Total Remaining 132.1
13H008 Flight Reports
Date Flt # Purpose of Flight Duration Running Total Hours Remaining
11/05/12 - 11/06/12871-0083Science24.246132.1
12H002 Flight Reports
Date Flt # Purpose of Flight Duration Running Total Hours Remaining
09/06/12 - 09/07/12872-0096Science19.325.5301.5
09/11/12 - 09/12/12872-0097Science25.751.2275.8
09/14/12 - 09/15/12872-0098Science22.473.6253.4
09/19/12 - 09/20/12872-0099Science24.898.4228.6
09/22/12 - 09/23/12872-0100Science25.1123.5203.5
09/26/12 - 09/27/12872-0101Science25.4148.9178.1

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: 

HS3 - Global Hawk #872 09/11/12 - 09/12/12 Science Report

Mission Summary: 

Hurricane and Severe Storm Sentinel (HS3) Mission

2012-09-11 to 12-09-12 Flight Report

This was the first full science flight for HS3, taking off from Wallops for an environmental mission into TD14/TS Nadine. The disturbance became Tropical Depression 14 about 15 UTC 11 September, ~4 h after takeoff, and became a tropical storm by 03 UTC 12 September. The goal of the flight was to examine the interaction of the storm with the Saharan Air Layer (SAL), in particular, to see if the SAL air was getting into the storm circulation.  Visible imagery at sunrise showed a clear dust layer on the eastern side of the storm and extending around the northern side. We flew a “lawnmower” pattern in order to get a broad survey of the storm and its environment, with good north-south cross sections through the storm and the SAL. Planning was perfect, but unfortunately, execution was not. The AVAPS instrument had several problems including RF interference of some sort and eventually a stuck sonde midway through the flight. We completed the rest of the flight without AVAPS and got excellent data from CPL and S-HIS. The stuck sonde was cause by the cap over the parachute coming off while in the dispenser.  The sondes will be more closely checked for future flights to make sure the problem does not occur again. The RF interference is being addressed by reducing the gain on the recievers so that they will be less sensitive to interference.


Flight Scientists:

Shift 1 (1600-0100 UT): Braun, Zipser

Shift 2 (0000-0900 UT): Houze, Hence, Hendricks

Shift 3 (0800-1600 UT): Newman, Thorncroft, Guimond

Shift 4 (1600-0845 UT): Braun, Doyle


Takeoff time: 1106 UTC


Caption: Visible image of target region at the time of takeoff. Some lightning is seen in the areas of convection around AL91. 

1143 At 47500 ft, leaving Test Track C

1321 Drop 1 launched. Location 33.3N, 65.1W.

1410 UTC 

Moving over a Narrow Cold-Frontal Rainband ~1403 UTC.  HDVis shows somewhat deep clouds to the left of the aircraft corresponding to the satellite image.

Caption: CPL real-time data for the crossing of the NCFR. 

1450 NHC has just released advisory for TD14.


Caption: The cloud-top images corresponds to 1543UTC at the begining of the lawnmower pattern. Almost all cloud tops are below 50kft. A very small amount of lightning near 46W, 19N.

1558 Drop 2 launched

1606 Drop 3 launched

1620 Drop 4 launched

1632 Drop 5 launched

1644 Drop 6 missed; can't confirm sonde in tube

1656 Drop 7 missed

1657 rebooting AVAPS

1658 proceeding southbound with some high cloud, not tops of 50Kft

1709 Drop 8 Launched

1722 Drop 9 Launched

1731 Drop 10 skipped due to "traffic"

1734 Drop 11 will be done after turning and wings level; that will be the procedure for all corners

1745 Drop 11 launched

1758 Drop 12 launched

1813 Drop 13 launched

1825 Drop 14 launched

1836 Drop 15 launched

1851 Drop 16 launched

1920 Drop 17 launched

           Drop 18 launched (Windows crashed, lost time info)

           Drop 19 launched (Windows crashed, lost time info)

1939 Drop 20 launched

1952 Drop 21 launched

2005 Drop 22 launched

2017 Drop 23 launched

2033  Drop 24 launched

2035 Lightning along track


2035 The cloud top heights along track at this time show the beginnin of a convective burst that moved off to the northwest.

2045 Drop 25 launched

2045 The lightning below was part of the convective burst that started along the flight track, moved west and peaked in size and intensity at about 2115 UTC.

2055 Drop 26 launched

2105 Drop 27

2117 Drop 28

2125 camera shot--cloud tops looking pretty high. This picture is not the best. The nose camera seemed to see very high cloud tops, consistent with

2129 Drop 29--error message noted by AVAPS

Going to miss Drops 30, 31, 32--AVAPS troubleshooting

2139 latest CPL

2148 Problem with Ku

22:10 AVAPS appears to fixed. Ready to load sonde for D33.

2209 The following shows the convective burst after it had moved northwest dropped off in intensity.

2217 Drop 33

2228 Drop 34

2240 Drop 35

2252 Drop 36

2308 Drop 37

2311 CPL time series--lots of stuff below the cirrus.

2318 Drop 38

2329 Drop 39

2341 Drop 40

2351 Drop 41

2357 More problems with AVAPS

0001 AVAPS down again, missing drop 42..

OVERALL for the last 8 hours. The convection has been generally inactive. A few tops penetrated to ~50 kft. Some occasional spotty lightning has occurred. The convection has never been intense enough to divert the a/c. But one fairly strong convective burst occurred at about 2015-2145 UTC. The AVN floater suggests the center may becoming better defined at the moment at about 17.5N/44.5W. Dry air has been evident in the soundings at midlevels. The center of the disturbance has never been well defined. The temperature and dewpoint together suggest subsidence in midlevels. The CPL data seem consistent with what is otherwise evident from satellite obs. Dropsondes have failed on 3 occasions leading to several missed sondes.

0025 AVAPS still down, missing drops 43 and 44.

0029 AVAPS says no more sondes possible on this mission.

0040 The decision of Newman, Houze, Thorncroft is to proceed with the mission without dropsondes. The CPL and S-HIS should be able to get data in the NE part of the pattern, as indicated by the dust extinction forecast and observations for ~2100 UTC in the images below. The continuation of the flight will also continue to test out the air traffic control system.

0100 Newman, Thorncroft, and Guimond take over the Mission Science duties. AVAPS is now dead, but saved. They have 3 problems: 1) hung sonde, 2) some broad instrument issues, and 3) some com problems with the sondes at 400mhz.

0140 CPL Quick Look shows the SAL as the enhanced return at about 3000 m.

0144 Turning onto the S track of lawnmower track 5.

0300 TS14 has been named Nadine. The NHC projects Nadine to be a Cat-1 in the 48-hr forecast 2012-09-14 at 0Z.

0321 Lots of cirrus on the N-S track with a bit of mid-level stuff.

0416 Began our final S-N track of the lawn mower pattern. Nice clear air according to CPL on the southern end of the track. Below is the plot of the 895-905 ScanningHIS channel showing very cold brightness temperatures near the core of the storm (big blue square). The SE corner shows relatively clear air, in good agreement with CPL.

0445 Pilots requested wind speeds at altitude during return to base.  LESSON LEARNED: Have the "pilot weather" print out prepared before each flight.

0607 Finishing our final track on the lawn mover. Agin, below is the plot of the 895-905 ScanningHIS channel showing fairly warm Bt over the length of this last track. This is plotted on top of the GOES IR. Note the excellent correspondence.

0744 Heading back to WFF.  Mostly over clear and relatively dry air.

TPW data at 00UTC 12 Sept clearly shows the dry air on the western and southern sides that is associated with subsidence. On the northern and eastern sides, the dry SAL air is seen.  Unfortunately, we got no drops in the SAL air mass and will have to rely entirely on remote sensing.

0913 UTC  Crossing front region.

CPL image for back (westward portion) of front. Multiple cloud layers over the front followed by a wide area of lower clouds.

Landing time: 1245 UTC