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Justyna Nicinska, Office of Oceanic and Atmospheric Research (OAR)
Russ Chadwick, Earth System Research Laboratory/OARRandy Johnson, Air Resources Laboratory/OAR
Jim Jordan, Earth System Research Laboratory/OARSandy MacDonald, Office of Oceanic and Atmospheric Research
Louis Wasson, Mississippi State University
WISDOM Intensity Program
Presentation Outline:
WISDOM Intensity ConceptAeroclipper ResultsWind ModelWHISSP DesignWHISSP Field ExperimentConclusions
Intensity Program
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WISDOM- started in 2008 with aim of designing a system for data collection in the synoptic environment, targeting remote areas of the ocean, days ahead of a hurricane’s landfall
Observing System Need: Providing continuous data in the eye of a tropical cyclone
Minimal data is presently available in the eye of a Tropical Cyclone
Concept for WISDOM Intensity work came from the French Aeoroclipper study-
Two blimps successfully reported back data from the eye of a TC in the Indian Ocean.
WISDOM-aim to develop a simpler, low cost version of the Aeroclipper.
Intensity Program
Research Needs:Currently pressure data is available for about 30% of Atlantic
storms and 5% of Pacific Storms.Filling existing data gaps may lead to improved intensity
forecasting.Data will help to understand and characterize the evolution of
the energy content of the low marine boundary-layer inflow to hurricanes
its relationship with hurricane intensity changes, the influence of ocean temperature, and estimates of surface fluxes.
Intensity Program
The AeroclipperJ.P. Duvel et al.,BAMS Jan09
Three Subsystems
Helium Balloon
50 m Tether Line
Surface Watercraft
Aeroclipper TrajectoriesGreen line – center of TC Dora 1200z 29Jan to 0000z 06Feb2007
Crosses – Aeroclipper locations 0300z 3Feb
White dots – wind data
Balloon position (Latitude, Longitude and Altitude)Wind speedWind directionBarometric pressureAir temperature Relative humiditySea surface temperatureSolar radiationOther sea surface measurements
Intensity Program
WHISSP Prototype Design Data Collection: Measurements that WHISSP can make above the ocean surface include:
Balloon and Watercraft Response Calculations
Inflated balloon diameter – 1.4 mBalloon and payload mass – 0.3 kgWatercraft mass – 3.0 kgTether line length – 50 mWind speed logarithmic in heightResults for low, medium, high winds
Intensity Program
Key Points for the Simple Wind Model For these parameters, watercraft travels at about
60% wind speed over wide range of wind speeds.
So, compare trajectories of a 60% unit (blue) with those of a 30% unit (yellow).
Comparing three launch pairs inside the hurricane and one launch pair from outside the hurricane.
(inside is less than 47 km radius out from the center)
Intensity Program
Wind Model ConclusionsEntrainment into hurricane is not as easy as
it may appear.
Starting inside Radius of Maximum Winds (RMW-red line) increases chances of entrainment, but does not guarantee it.
Unit more responsive to wind has greater chance of entrainment.
Intensity Program
2010 WHISSP ExperimentProof of Concept with low cost experimental
model:
Balloon – 6 foot diameter balloon carrying a WISDOM 100 gram payload.
Tether line – 164 ft. light plastic string.
Watercraft – 40 ft of half inch and one inch silicone tube
Launched four units in December 2010.
Intensity Program
Balloon during inflation test
Intensity Program
Balloon with SailIntensity Program
Assembled payload housing
Intensity Program
WHISSP Experimental Model Trial Four WHISSP experimental were models launched from
Tybee Island GA December 3-4, 2010.
Balloons 9 and 12 were launched on December 3rd and balloons 35 and 38 were launched on December 4th. In chronological and numerical order the balloon lift for the balloons was -60g, -180g, -300g, and -420g. The negative sign indicates that the weight of the ballast hose attached to the balloon is that many grams heavier than the net lift of the balloon.
In all of the launches the balloon ultimately lifted the ballast
hose entirely out of the water and rose to higher altitudes rather than staying at the planned 150 feet.
About one week after the launch 2 out of 4 balloon tags continued reporting data and were floating about 50 meters above the sea surface.
Intensity Program
WHISSP LaunchIntensity Program
Intensity Program
WHISSP Test FlightsIntensity Program
Graph of Altitude for WHISSP units showing all data (including error contaminated) received at the ground station between December 3 and December 16, 2010. While the altitude data cannot be assumed to be valid, this does show that all of the units operated for at least a day and that 3
of the 4 operated for more than a week and one operated for nearly 2 weeks.
Intensity Program
WISDOM Intensity 2010-12 Program:Completed study to develop a prototype
WHISSPESRL, ARL, UAS and NHC partnering on in-
house OAR effortTested experimental model in 2010 –
demonstrated proof-of-conceptEvaluate alternative SATCOM and payload
optionsTwo design concepts to evaluate in addition to
WHISSP (USV and “beach ball)Continue engineering efforts to develop
advanced model of the WHISSP for data collection in Hurricane Eye
Field testing in Hurricane Eye by 2011-2012
THANK YOU!26
Aeroclipper WindsEntrainment phase data
Zero angle is TC Dora’s course
Black crosses show eyewall
Response to Low Wind Conditions
Response to Medium Wind Conditions
Response to High Wind Conditions
Concept for airborne deployment Balloon – one to three meter plastic
balloon with measurement electronics and GPS
Tether line – air dielectric coax cable for tether, helium path up, power path up, data path down
Watercraft – batteries, computer, GPS, satellite communications, helium tank
Wind Model based on Aeroclipper DataTangential wind as function of radius r W(r) = K r exp(-r/RMW) K chosen so W(r)=40 m/s when r=RMW, the Radius of Max Winds, red circles for 47 km.
Radial winds inward at 25% of tangential winds
Upper level steering winds pushing hurricane northward at 12 m/s