Evaluation of the CAM and PX Surface Layer Parameterization Schemes for Momentum and Sensible Heat Fluxes Using Observations
In this study, the performances of the Community Atmosphere Model (CAM) and Pleim–Xiu (PX) surface layer parameterization schemes are investigated by using field observations. The parameterization schemes are evaluated against continuous momentum and sensible heat flux observations measured at two flat and homogeneous grassland sites in the suburb of Nanjing, eastern China. The observations were conducted from 30 December 2014 to 18 April 2017 at Jiangxinzhou and from 9 February 2015 to 26 March 2018 at Jiangning. It is found that the momentum flux is overall in good agreement with the observation, and the sensible heat flux is overestimated. The parameterizations of the momentum and sensible heat fluxes well capture the diurnal and seasonal patterns seen in the observations at the two sites. At Jiangxinzhou, the PX parameterization underestimates the momentum flux throughout the day and the CAM parameterization slightly overestimates it around the noon, while they underestimate the momentum flux throughout the year. The two parameterizations overestimate the sensible heat flux in the daytime as well as over the entire year. At Jiangning, the two parameterizations overestimate the momentum flux throughout the day and the sensible heat flux in the daytime, and overestimate both of them over the entire year. The two parameterizations are not significantly different from each other in reproducing the turbulent fluxes at the same site, while they perform differently at the two sites in terms of statistics. In addition, the parameterized fluxes increase with increased roughness length.
Key wordsevaluation parameterization turbulent fluxes surface layer
Unable to display preview. Download preview PDF.
The authors declare that there is no conflict of interest regarding the publication of this paper. The authors thank the anonymous reviewers for their constructive criticism and comments, which have greatly helped to improve the quality of this study.
- Castelli, S. T., S. Falabino, L. Mortarini, et al., 2011: Investigation of surface-layer parameterizations on the basis of the UTP experimental campaign in Turin city. EMS Ann. Meet. Abstr., 8, EMS2011-180.Google Scholar
- Collins, W. D., P. J. Rasch, B. A. Boville, et al., 2004: Description of the NCAR Community Atmosphere Model (CAM 3.0). NCAR/TN-464+STR, NCAR Tech. Rep., Boulder, Colorado, 214 pp.Google Scholar
- Freedman, F. R., and M. B. Ek, 2004: Testing NCEP operational surface layer parameterizations for stable conditions using CASES-99 data. 16th Symposium on Boundary Layers and Turbulence, Portland, Maine, USA, 9–13 August 2004, Amer. Meteor. Soc., 5 pp.Google Scholar
- Monin, A. S., and A. M. Obukhov, 1954: Basic laws of turbulent mixing in the surface layer of the atmosphere. Trudy Geofiz. Inst. Akad. Nauk SSSR, 24, 163–187.Google Scholar
- Pleim, J. E., and A. J. Xiu, 2003: Development of a land surface model. Part II: Data assimilation. J. Appl. Meteor., 42, 1811–1822, doi: 10.1175/1520-0450(2003)042<1811:DOA LSM>2.0.CO;2.Google Scholar
- Schuepp, P. H., M. Y. Leclerc, J. I. MacPherson, et al., 1990: Footprint prediction of scalar fluxes from analytical solutions of the diffusion equation. Bound.-Layer Meteor., 50, 355–373, doi: 10.1007/BF00120530.Google Scholar
- Skamarock, W. C., J. B. Klemp, J. Dudhia, et al., 2008: A Description of the Advanced Research WRF Version 3. NCAR/TN-475+STR, Boulder, Colorado, USA, NCAR Technical Note.Google Scholar
- Sodemann, H., and T. Foken, 2003: Evaluation of a parameterisation for turbulent fluxes of momentum and heat in stably stratified surface layers. Geophys. Res. Abstr., 5, 05126.Google Scholar
- Tassone, C., and M. Ek, 2015: Ameriflux data used for verification of surface layer parameterizations. Geophys. Res. Abstr., 17, EGU2015-6815.Google Scholar
- Wu, W., Y. G. Liu, and A. K. Betts, 2012: Observationally based evaluation of NWP reanalyses in modeling cloud properties over the Southern Great Plains. J. Geophys. Res. Atmos., 117, D12202, doi: 10.1029/2011JD016971.Google Scholar
- Xiu, A. J., and J. E. Pleim, 2001: Development of a land surface model. Part I: Application in a mesoscale meteorological model. J. Appl. Meteor., 40, 192–209, doi: 10.1175/1520-0450(2001)040<0192:DOALSM>2.0.CO;2.Google Scholar
- Zilitinkevich, S. S., 1970: Dynamics of the Atmospheric Boundary Layer. Leningrad Gidrometeor, Leningrad, 291 pp.Google Scholar