Analysis of modified MYJ and YSU boundary layer schemes in WRF

Geophysical Research Abstracts
Vol. 16, EGU2014-6802-1, 2014
EGU General Assembly 2014
© Author(s) 2014. CC Attribution 3.0 License.
Analysis of modified MYJ and YSU boundary layer schemes in
WRF-Chem with respect to simulated boundary layer heights and
pollutant concentrations
Renate Forkel, Richard Foreman, and Stefan Emeis
Karlsruher Institut für Technologie (KIT), IMK-IFU, Garmisch-Partenkirchen, Germany ([email protected])
To improve the performance of boundary layer schemes currently applied within WRF-Chem (Grell et al., 2005),
the Mellor-Yamada-Janjic (MYJ) model (Mellor and Yamada 1982) and the Yonsei University (YSU) PBL scheme
(Hong et al. 2006) have been updated using data from a 100 m high offshore measurement tower called FINO1.
The turbulence intensity in the Mellor-Yamada-Janjic model has been enhanced as described in Foreman and
Emeis (2012). An alternative to the exchange coefficient for stable stratification in the YSU scheme is described
in Foreman et al. (2014). These modifications to the two schemes have been applied and are compared with the
existing schemes. For example, the updated MYJ scheme results in an improved representation of the turbulent
kinetic energy throughout the boundary layer as compared with the measurements at FINO1. The modified MYJ
and YSU schemes, which have been originally developed for wind energy applications, have been implemented
into version 3.5 of the WRF model. Simulations with WRF-Chem were carried out for Europe and the region
of Augsburg in order to evaluate the effect of the modified PBL schemes on simulated PBL heights, gas phase
pollutant and aerosol concentrations.
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kinetic energy equation approaches. Submitted to Boundary Layer Meteorology 2014.
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