Shuyi S' Chen

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Air-Sea Coupled Modeling and Ocean Observations
in Hurricanes
Shuyi S. Chen Rosenstiel School of Marine and
Atmospheric Science University of Miami
(Ocean Platforms Workshop, Boulder, 27-28 October
2008)
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• Factors Controlling Intensity Change
• Inner core (eye and eyewall) dynamics
• (Previous theoretical and modeling works, and
  recent field program RAINEX, Houze et al. 2006,
  2007)
• Environmental conditions, including vertical wind
  shear, moisture distribution, and sea surface
  temperature (upper ocean heat content), surface
  properties (waves, sea spray), etc.
• (Previous theoretical, observational, and
  modeling works, and recent results from CBLAST,
  Black et al. 2007, Chen et al. 2007, 2008a,b)

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Sponsored by
Parners
In the eye of Katrina (2005)
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1.67 km Resolution Model Forecasts for Hurricane
Rita
Airborne Radar Observed Ritas Concentric Eyewalls
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Effects of Environmental Water Vapor on Hurricane
Rainbands, Eyewall Replacement and Intensity
Change
TRMM TMI Total Precipitable Water
dry
humid
Katrina
Rita
Dots represent sample G-IV dropsonde locations
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Sample P3 Dropsonde Locations
Rita
Katrina
Black dots represent sample P3 dropsonde
locations along the flight tracks
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Daily Composite Environmental Relative Humidity
Profiles
G-IV
MM5
Katrina moist
Katrina moist
Rita dry
Rita dry
Number of dropsondes Aug 27 20
Sept 21 21 Aug 28 21
Sept 22 22
250-600km mean profile
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Daily Composite Rainband Relative Humidity
Profiles
P3
MM5
Rita Moist
Rita Moist
Katrina Dry
Katrina Dry
Number of dropsondes Aug 27 27
Sept 21 34 Aug 28 25
Sept 22 9
Profiles along simulated flight tracks in model
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Hypothesis/Conceptual Model of How Moisture
Gradient Affects Rainband Organization
Dry/Stable
Moist/Unstable
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CBLAST
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(No Transcript)
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High-resolution Coupled Model Forecast of
Hurricane Katrina
Surface Wind Speed (m/s)
RainRate
Significant Wave Height (m)
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High-resolution Coupled Model Forecast of
Hurricane Katrina
Rain
SST and ocean surface current
CHPR
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HYCOM
Pre-Katrina
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Observed Hurricane Ike
High-resolution (1.3km) model forecast of
Hurricane Ike
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UM Mini-ensemble forecast of Hurricane Ike
UMCM
Operational Hurricane
Operational Hurricane
UMCM
GFS
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Total Surface Heat Flux
Uncoupled
Coupled Atmos-Wave-Ocean
Observed from GPS Dropsondes
Observed from airborne turbulence probes
(Zhang Drennan)
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West Pacific Typhoons (2006)
Three typhoons over the western North Pacific
shown by the Moderate Resolution Imaging
Spectroradiometer (MODIS) on NASAs Aqua
satellite at 0435 UTC on 7 August 2006.
SST cooling (oC) induced by three typhoons
(Bopha, Maria, and Saomai) from 3-10 Aug 2006.
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Seasonal Arrays
ONR DRI Typhoon in W Pac 2009-14