Background Research Applications

Philip Hayes

The Florida State University

Area Topics of Research

• High-resolution modeling of jet dynamics using the WRF model.

• High-resolution modeling of hurricanes using the HWRF model.

• Theoretical and observational validation of remotely sensed data.

WRF Model Experience

• Balanced and Unbalanced Flow in Primitive Equation Simulations of Baroclinic Wave Life Cycles

• Examined the destabilization of a baroclinic jet by augmenting the shape of the dynamic tropopause using the WRF model.

• Observed the horizontal divergence field and the residual of the Non-linear Balance Equation.

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Non-linear Balance Equation

WRF Model Knowledge

• Experienced operation of the WRF model.

• Calculated and created numerical profiles of new parameter variables.

• Comfortable with developing new modules in the WRF model.

• Used Vis5D software & NCAR graphics.

HWRF Model

• Produced numerous sensitivity studies on:– horizontal resolution– vertical resolution– boundary conditions– one-way/two-way interactive nesting

• Incorporated a module that compensates for sea spray effects.

• Created shell scripts to operate and run the HWRF model.

Remotely Sensed Research

• Determining Surface Winds from Doppler Radar Data during Hurricane Passages over Florida

• Primary objective of research: produce high resolution spatial fields of surface (10 m) winds using Level II archived Doppler radar data.

• Research required:– Creative and unique techniques to obtain the results.– Knowledge of error statistics and validation

techniques.– Ability to use multiple programming languages and

software packages.

Radial Velocity Dilemma

Radial velocity = 0 mph.

Radial velocity = 150 mph

• Measures component of wind along radar beam.

• Wind component tangential to beam seen as zero, parallel to beam measures full 2-D wind.

• Produces data gaps throughout the velocity field.

• Algorithm must be created to convert radial velocity field into a total wind field.

Hurricane Jeanne

Total Wind Calculation

• Used C++ programming incorporated into the Warning Decision Support System – II (WDSS-II) to quality control, unfold, and output the correct velocity data.

• Created Fortran algorithm that received this data and calculated a total wind field from only radial velocities.

Reduction Factor Process

• Must compensate for the variability of the boundary layer over land.

• Reduce all gridpoints using Monin-Obukhov Similarity Theory

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Roughness Length• As surface layer becomes rougher, wind speed decreases more rapidly with height due to frictional effects. • Hazards United States (HAZUS) project contain roughness length plots within Florida at a resolution of 111.11 m.• Later research will use effective roughness length.

GIS Land Use Data• Land use/Land coverage data collected by 4 Water Management Districts

•South Florida•Southwest Florida•St. John’s •Suwannee River

• Dataset derived by photo- interpreting 1:12,000 UGSG color infrared digital orthophoto quarter quadrangles.

TOTAL WIND(before reduction)

SURFACE WIND(after reduction)

• Animation of Hurricane Jeanne (2004).• Maximum wind speed before reduction ~ 121 kts.• Maximum wind speed after reduction ~ 88 kts.• Strongest winds offshore.

TOTAL WIND(before reduction)

SURFACE WIND(after reduction)

• Animation of Hurricane Jeanne (2004).• Maximum wind speed before reduction ~ 121 kts.• Maximum wind speed after reduction ~ 88 kts.• Strongest winds offshore.

Surface Wind Swath between 0926_00Z and 0926_06Z

• Hurricane strength winds pictured in green and warmer.• Strongest winds north of the hurricane track.• Validation of wind speeds vs. ASOS data is sparse.

GIS Display

Validation Issues• Sparse ASOS data limits the validation of the Doppler-derived wind field.• ASOS failures common due to high winds, flying debris, and design faults.• Data collected by ASOS may contain errors of up to 10.5% for land-based observations (Powell et al. 1996).• Other methods for validation must be explored. KMLB

Observational Data

• Florida Coastal Monitoring Program

• Data provided by U.F. Professor Dr. Gurley• Measures ground level winds with four portable

towers.

Research Experience

• Early research with WRF/HWRF required strong ability to work in team environment.

• Ph.D. research heavily involved generating products and results independently.

• Quickly learned new applications needed to complete research (i.e. GIS, Matlab, Grads scripting).