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Lab Postdoc Jiachuan Yang join HKUST as assistant professor

Professor Bou-Zeid talks about the challenges cities face in the 21st century

 

ABL Parameterization


Sensor Networks


Large Eddy Simulations


Multiscale Atmospheric Simulations


Urban Micrometeorology and Energy Studies


Turbulence Structure


Multiscale-Atmospheric Simulations Using WRF

The aim of this study is to reconstruct, by means of atmospheric numeric simulations, the most realistic and detailed state of the atmospheric boundary layer. This will move us from idealized to "real-world" ABL simulations and will allow us, for example, to study land-atmosphere interaction during a whole diurnal cycle over urban areas. To that end, we run a mesoscale non-hydrostatic atmospheric model, the Weather Research and Forecast (WRF) model, in a configuration that consists of 3 two-way nested simulation domains starting at a domain size of 10,000 km feeding into 3 additional two-way nested simulations in WRFʹs LES mode; the LES simulations reach down to domain sizes of a few kilometers and grid resolutions of about 40 m in the horizontal direction and a few meters in the vertical direction (stretched grid, see figure below). This increased resolution and nested configuration will ensure that mesoscale variability at the smallest scales is captured.

 

 

The WRF model is initialized with the finest resolution data:

  • Meteorological data are provided by North American Regional Reanalysis (NARR) data, having a horizontal resolution of 32 km, for initial and boundary conditions. The meteorological parameters are updated at a 3-hourly frequency.

  • The soil moisture content is provided by NLDAS data and has a resolution of 1/8 degree, data updated hourly.

  • The land use and topography data implemented in the model are provided by the U.S. Geological Survey, respectively form NLCD 2001 data and SRTM data with a resolution of 1 arc second (30 m) (see figure below).

These nested WRF simulations can subsequently be used to provide realistic mesoscale forcing to the pseudospectral LES code that allows an explicit 3D representation  of urban canopies. These simulations are being compared to experimental data over Princeton (see Figure below) acquired by our collaborators in the The Hydrometeorology Research Group. Work is also ongoing to integrate these simulation with data from sensor networks (e.g. SNOP, mesonet / CCNY network) to provide accurate measurements at fine resolution of surface fluxes and skin temperature to our models.

 

 

last update on: August 05, 2011 14:02,  contact webmaster

Contact Information

Elie Bou-Zeid
Department of Civil & Environmental Engineering
Princeton University, C326 EQuad
Princeton, NJ 08544, USA

phone  :  +1-609-258-5429
fax        :  +1-609-258-2799
email   :  
ebouzeid@princeton.edu
web      :  http://efm.princeton.edu/