Comparison of Observed, MM5 and WRF-NMM Model-Simulated, and HPAC-Assumed Boundary-Layer Meteorological Variables for 3 Days During the IHOP Field Experiment

• Published in: Boundary-layer meteorology Vol. 134; no. 2; pp. 285 - 306
• Main Authors: Hanna, Steven R, Reen, Brian, Hendrick, Elizabeth, Santos, Lynne, Stauffer, David, Deng, Aijun, McQueen, Jeffrey, Tsidulko, Marina, Janjic, Zavisa, Jovic, Dusan, Sykes, R. Ian
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.02.2010; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Atmospheric boundary layer; Atmospheric models; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric research; Atmospheric Sciences; Convection, turbulence, diffusion. Boundary layer structure and dynamics; Dispersion; Dispersion models; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Evaluation of models; Exact sciences and technology; External geophysics; Geophysics. Techniques, methods, instrumentation and models; International H2O project (IHOP); Kinetic energy; Mesoscale meteorological models; Meteorology; Surface fluxes of heat and momentum; Turbulence; Turbulent kinetic energy; Wind; Wind speed; United States; International H2O project (IHOP); Turbulent kinetic energy; Dispersion models; Surface fluxes of heat and momentum; Evaluation of models; Mesoscale meteorological models; Atmosphere model; International H20 project (IHOP); Time series; Model output; North America; Mesoscale; parametrization; Momentum transfer; Stable boundary layer; algorithm performance; Atmospheric boundary layer; Vertical profile; Observation data; Turbulence energy; heat transfer; Comparative study; Boundary layer turbulence
• ISSN: 0006-8314; 1573-1472
• DOI: 10.1007/s10546-009-9446-7

The objective of the study is to evaluate operational mesoscale meteorological model atmospheric boundary-layer (ABL) outputs for use in the Hazard Prediction Assessment Capability (HPAC)/Second-Order Closure Integrated Puff (SCIPUFF) transport and dispersion model. HPAC uses the meteorological models' routine simulations of surface buoyancy flux, winds, and mixing depth to derive the profiles of ABL turbulence. The Fifth-Generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) and the Weather Research and Forecast-Nonhydrostatic Mesoscale Model (WRF-NMM) ABL outputs and the HPAC ABL parameterisations are compared with observations during the International H2O Project (IHOP). The meteorological models' configurations are not specially designed research versions for this study but rather are intended to be representative of what may be used operationally and thus have relatively coarse lowest vertical layer thicknesses of 59 and 36 m, respectively. The meteorological models' simulations of mixing depth are in good agreement (±20%) with observations on most afternoons. Wind speed errors of 1 or 2 ms⁻¹ are found, typical of those found in other studies, with larger errors occurring when the simulated centre of a low-pressure system is misplaced in time or space. The hourly variation of turbulent kinetic energy (TKE) is well-simulated during the daytime, although there is a meteorological model underprediction bias of about 20-40%. At night, WRF-NMM shows fair agreement with observations, and MM5 sometimes produces a very small default TKE value because of the stable boundary-layer parameterisation that is used. The HPAC TKE parameterisation is usually a factor of 5-10 high at night, primarily due to the fact that the meteorological model wind-speed output is at a height of 30 m for MM5 and 18 m for WRF-NMM, which is often well above the stable mixing depth. It is concluded that, before meteorological model TKE fields can be confidently used by HPAC, it would help to improve vertical resolution near the surface, say to 10 m or less, and it would be good to improve the ABL parameterisations for shallow stable conditions.