New TKE scheme improved CanAM4 simulated 2-m air temperature

A new semi-empirical diagnostic turbulent kinetic energy (TKE) scheme has been developed to represent downgradient turbulent transfer processes for both clear and cloudy conditions within CNRCWP. Four members from University of Victoria and CCCma including co-investigators contributed their expertise to this project. The scheme is compared with the default parameterization in the CanAM4 using three single-column modeling cases (Cabauw, ARM2X, and DYCOMS). In general, the new one performs comparably well on both stable, convective, and cloud-topped boundary layer cases. It is currently implemented and tested in the CanAM4 GCM18, the warm bias in the simulated annual screen temperature anomaly from observations has been partially corrected using new TKE scheme over land regions such as over South American, Russian, and northern part of Australia.

More progress will be reported in future blog posts.

CCCma CanAm4 simulated annual mean surface screen temperature anomaly from observations in the GCM18 operational version (upper panel) and the GCM18 latest TKE version (lower panel) from Jan. 2004 to Dec. 2008.

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