Mission Summary
20150825I1 Aircraft 43RF
SALEX mission Storm Erika

Aircraft Crew (43RF)
Aircraft CommanderScott Price
Co-pilotPat Didier
Co-pilotNate Kahn
NavigatorJason Siegel
Flight DirectorIan Sears
Flight EngineerJoe Klippel
Flight EngineerChris LaLonde
Data TechnicianDana Naeher
Elec. TechnicianJeff Smith
Elec. TechnicianBobby Peek

Scientific Crew (43RF)
Lead ScientistPaul Reasor
Radar ScientistSim Aberson
Doppler Wind Lidar ScientistLisa Bucci

Figure 1: Initial flight plan for the mission into Tropical Storm Erika.
Green dots are the turn points. Purple and red dots
represent locations of rawinsonde observations.

Mission Plan :

An Environmental Modeling Center-tasked Tail Doppler Radar (TDR) Mission into Tropical Storm Erika, which was moving rapidly westward toward the Leeward Islands. The plan was for a butterfly pattern (90 nmi legs) with three passes through the center of Erika with a return to Barbados (Fig. 1).

Prepared by the Hurricane Research Division
August 24, 2015
Aircraft: N43RF
Proposed takeoff: 25/1800Z
deg min deg min naut mi/deg nmi nmi hr:min
1BARBADOS 0.0. 0:01
2S 15 00 53 47 120/240 352. 352. 1:29
3S 17 01 50 12 120/060 240. 592. 2:30
4S 18 30 52 00 150/000 136. 728. 3:05
5S 13 30 52 00 150/180 300.1028. 4:20
6S 15 00 50 13 120/120 137.1166. 4:55
7S 17 01 53 48 120/300 240.1406. 5:56
8BARBADOS407.1813. 7:18

Mission Summary :

Take off Landing
Barbados, BWI17:49 UTC Barbados, BWI00:22 UTC

Figure 2: Reflectivity from the lower-fuselage radar at the times closest to the three center fixes.

At the beginning of the mission, Erika was located about 1030 km east of the Leeward Islands and moving rapidly westward at 31 km h1 . The maximum sustained wind speed was 75 km h1 , making it a weak tropical storm, and the minimum central pressure was estimated to be 1003 hPa. Convection had been decreasing near the core, with most convection off to the south suggesting moderate to strong wind shear. Satellite-based humidity data did not show much dry air near the core of Erika, suggesting the possibility of some slow intensification despite the shear. During the mission, convection waned as the time approached local convective minimum, and the center became exposed on the northern edge of the convection. Reflectivity from the lower-fuselage radar (Fig. 2) showed moderate convection mainly to the southeast of the center with little banding structure evident. None of the dropwindsondes released reported winds of tropical-storm force at the surface.

Figure 3: Doppler radar/dropwindsonde storm-relative composite
of Tropical Storm Erika valid 2114 UTC 25 August.

In support of the commensurate Saharan-Air Layer Experiment from the NOAA G-IV, additional dropwindsondes were released in gradients of humidity at flight level. Though satellite-based humidity observations did not show dry air within the core of Erika, dropwindsonde observations showed regions with relative humidity values below 60% (Fig. 3), explaining the inability of Erika to intensity. Three radar analyses and 19 dropwindsonde reports were successfully transmitted during the mission.

Problems :

Sim Aberson
Sept. 3, 2015

Mission Data :

Flight track

Temperature and Moisture

Wind and Atlitude

Lead Scientist's log | Radar Scientist's log | Dropsonde Scientist's log
Flight Director's log | Flight Director's manifest | NetCDF data | 1 second data | serial data

Page last updated December 03, 2015
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