Project Number: 12-TN1
Title: Investigation of surface layer parameterization of the WRF model and its impact on the observed nocturnal wind speed bias
Lead PI: Daniel Tong
Institution(s) Represented: University of Maryland - Daniel Tong
AQRP Project Manager: Gary McGaughey
TCEQ Project Liaison: Bright Dornblaser
Awarded Amount: $64,994.00

Abstract
Investigation of surface layer parameterization of the WRF model and its impact on the observed nocturnal wind speed bias
 
This study investigates surface layer parameterizations in the Weather Research and Forecasting (WRF) model. The parameterization of energy fluxes from the surface layer significantly impacts the modeled near-surface winds. The WRF model tends to over-predict the surface wind speeds in eastern Texas in the evening hours, especially in coastal regions. This project examines the various similarity theories that parameterize the momentum fluxes of the surface layer used in the WRF meteorological model.
 
The investigation and possible remedy recommendation for rectifying the high wind-speed-bias is carried out in multiple steps: (A) Understand the sensitivities of the different surface layer schemes, (B) Examine the sensitivity of the flux-profile relationships with regards to synoptic and atmospheric stability conditions, and (C) Investigate the universal flux profile functions and the range of parameter values used by the functions to suggest potential modifications for improvement - especially for the stable regimes. These details of the surface layer schemes are important as they govern the correct timing of the decoupling of near-surface and surface phenomena which are critical in the redistribution of kinetic energy from the residual layer to the surface. The rate of transfer of energy affects the evolution of wind speeds in the lowest layers.
 
A series of sensitivity runs of the WRF model is devised and conducted with possible recommendation on adjusted values for several of the tunable constants in the surface layer similarity theory parameterizations. Although the runs will focus on an early summer period for the Houston-Galveston-Brazoria area, they should provide insight on the rate and strength of the coupling and decoupling between the surface layer and the lowest model level in a large range of land-use and meteorological conditions.




Executive Summary: projectinfoFY12_13\12-TN1\12-TN1 Executive Summary.pdf
Work Plan: projectinfoFY12_13\12-TN1\12-TN1 Work Plan.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 Mar 2013 MTR.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 Apr 2013 MTR.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 May 2013 MTR.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 Jun 2013 MTR.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 Jul 2013 MTR.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 Aug 2013 MTR.pdf
Technical Report(s): projectinfoFY12_13\12-TN1\12-TN1 Sep 2013 MTR.pdf
 
QAPP: projectinfoFY12_13\12-TN1\12-TN1 QAPP.pdf
 
Final Report: projectinfoFY12_13\12-TN1\12-TN1 Final Report.pdf
Publications & Citations
Presentation: "A regional chemical reanalysis prototype" Pius Lee , Greg Carmichael, Tianfeng Chai, Rick Saylor, Li Pan, Hyuncheol Kim, Daniel Tong, and Ariel Stein Poster: "Preliminary analyses of flight measurements and CMAQ simulation during Southeast Nexus (SENEX) field experiment" Li Pan, Pius Lee , Hyun Cheol Kim, Daniel Tong ,Rick Saylor and Tianfeng Chai Publication: Pius Lee, Fantine Ngan, Hang Lei, Barry Baker, Bright Dornblaser, Gary McGauhey,and Daniel Tong. An Application for Improving Air Quality: a Houston Case Study, Earthzine 2014 [available at: http://www.earthzine.org/2014/03/29/an-application-for-improving-air-quality-a-houston-case-study/?shareadraft=baba698217_53330c8eab882]