Mission Summary
20120828H1 Aircraft 42RF
Tropical Storm Isaac TDR flight

Aircraft Crew (42RF)
Aircraft CommanderMark Nelson
Co-pilotMark Sweeny
Co-pilotChris Kerns
NavigatorChris Slaon
Flight EngineerPaul Darby
Flight EngineerKen Heystek
Flight DirectorIan Sears
Data TechnicianJoe Bosko
EngineerCharles Lynch
EngineerCarlos Quiles
Electronics TechnicianBill Olney
Scientific Crew (42RF)
Lead ScientistFrank Marks (HRD)
Dropsonde ScientistKathryn Sellwood(HRD)
AXBT ScientistBenjamin Jaimes(RSMAS)
AXBT ScientistJodie Brewster(RSMAS)
AXBT ScientistRyan Schuster(RSMAS)

Proposed track

Mission Plan :

NOAA42 will fly a tail Doppler radar (TDR) mission into Tropical Storm Isaac to gather tail Doppler data.


NOAA42 will take off from Jacksonville International at 0800 UTC and will recover at Jacksonville International by 1600 UTC the next day. The flight plan (see figure below) called for a rotating Figure 4 pattern with 105 nm legs at 8,000 ft with AXBT/dropsonde combos at the end, middle, and RMW on each leg, and on the first and last penetration. Doppler analyses and quality control would be done on the aircraft and for the first time we would have someone on the ground (Mike Black) do dropsonde quality control. An array of AXCP/CTDs will be deployed as part of the TC-Ocean interaction experiment.

Mission Summary :

Take off Landing
Jacksonville, FL07:46 UTC Jacksonville, FL16:04 UTC

As Tropical Storm Isaac approached landfall in Louisiana near the Mississippi. NOAA42 missions collected airborne Doppler radar data to use in initializing and evaluating model guidance (see flight track below). It was clear from the center drops that the central pressure was around 977 hPa and the SFMR suggested peak surface winds between 60 and 64 kts.

Included here you see images of the horizontal winds within the inner core of Tropical Storm Isaac sampled from the tail Doppler radar on the NOAA42 early on 28 August 2012. These images are at three altitudes, 1 km, 3 km, and 6 km, using a composite of winds from four legs oriented north-south, east-west, southwest-northeast, and northwest-southeast. Also plotted on the 1-km altitude analysis are the locations of dropsondes deployed (plotted using standard station symbols). Isaac's circulation is much more organized than in the previous mission, with a clear circulation center at all altitudes shown, but still asymmetric with the strongest winds north and east of the circulation center. This asymmetry increases with increasing altitude, and it is very pronounced at altitudes >6 km. The strongest winds at 1 and 3-km altitude are above hurricane force, however the surface winds from the SFMR and dropwindsondes suggested the hurricane force winds were not reaching the surface until very late in the mission. Hence, NHC did not name Isaac a hurricane until right after the P-3 left the storm. The circulation center is only slightly tilted from south to north with increasing altitude from 1-km altitude to 6-km, much less so than the previous missions. However, the increasing asymmetry with increasing altitude suggests that the southerly shear Isaac is embedded in is still a factor in its slow development.

Satellite imagery (below) depicted the cloud and precipitation structure during the missions. The top left image show the IR brightness temperatures that show a very asymmetric high cloud distribution with the coldest cloud tops (or the central dense overcast) to the southeast of the circulation center and very little cold cloud north of the center. There were cold clouds rotating around to the north of the center. The top right image shows the visible cloud filed with a few tall convective turrets in the rainbands north and west of the center. Other than those turrets the vast majority of the high bright clouds are to the south and east of the center. The bottom two images are showing the condensed precipitation, where the lower left image is the 37-GHz color image that shows the emission signal from rain in the blue-green colors and the scattering emission signal from large ice in the pink colors. The lower right image depicts estimates of rain. Both images suggest that the heaviest rain was in the bands the north and west of the center, with strong ice scattering in convective turrets embedded in the cold cloud shield southeast of the center. The rain emission signal suggests bands are wrapping around the center, but there is very little ice scattering on the northwest side.

33 GPS dropsondes were deployed, processed and transmitted during the mission. The figure below depicts the synoptic map of the surface observations from the dropsondes.

Evaluation :

This was a very successful mission that met all objectives without any major issues. 5 radar analyses, sets of superobs and radial files were completed and transmitted to the ground. The dropsonde quality control from the ground worked wonderfully. M. Black was able to receive all the dropsondes, quality control them, notify us when they were completed, and we were able to grab them from the AOML ftp site and transmit them from NOAA42. The upper-ocean in-storm pattern was also very successfully executed with >85% of the ocean probes working. The largest failures were in the AXCPs (50%).
The tail radar transceiver was swapped out for this mission with the spare.

Problems :

We had a few radar system glitches when the power cycled once during the mission. No significant amount of radar data was lost during the power glitches. The tail antenna was stuck in the forward position for about 4 minutes on our inbound leg from the northeast (1320-1324 UTC). The WSRA was not working during the flight and no WSRA data was collected. There were some issues with the HDOB wind directions transmitted on our east-west leg suggesting that there may be a bug in AAMPS causing an 180° ambiguity in the wind direction between north and south.

Expendables used in mission:
GPS sondes : 33
AXBTs : 20 (18 good)
AXCTDs: 11 launched (10 good)
AXCPs: 8 launched (5 good)
Sonobuoys: 39 total (33 good)
Frank D. Marks
Sept. 18, 2012

Mission Data :

Flight Director log | LPS log | LPS digital Log | Radar log | Drop log

Serial data | 1 second data | NetCDF file | Raw Fast data (NetCDF) | SFMR data (NetCDF)

Flight track

Temperature and Moisture

Wind and Atlitude

Page last updated Feb. 20, 2013
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