World Library  

Add to Book Shelf
Flag as Inappropriate
Email this Book

Calibration of Aerodynamic Roughness Over the Tibetan Plateau with Ensemble Kalman Filter Analysed Heat Flux : Volume 16, Issue 11 (20/11/2012)

By Lee, J. H.

Click here to view

Book Id: WPLBN0004010611
Format Type: PDF Article :
File Size: Pages 12
Reproduction Date: 2015

Title: Calibration of Aerodynamic Roughness Over the Tibetan Plateau with Ensemble Kalman Filter Analysed Heat Flux : Volume 16, Issue 11 (20/11/2012)  
Author: Lee, J. H.
Volume: Vol. 16, Issue 11
Language: English
Subject: Science, Hydrology, Earth
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Publication Date:
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications


APA MLA Chicago

Timmermans, J., Su, Z., Mancini, M., & Lee, J. H. (2012). Calibration of Aerodynamic Roughness Over the Tibetan Plateau with Ensemble Kalman Filter Analysed Heat Flux : Volume 16, Issue 11 (20/11/2012). Retrieved from

Description: Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, Italy. Aerodynamic roughness height (Zom) is a key parameter required in several land surface hydrological models, since errors in heat flux estimation are largely dependent on optimization of this input. Despite its significance, it remains an uncertain parameter which is not readily determined. This is mostly because of non-linear relationship in Monin-Obukhov similarity (MOS) equations and uncertainty of vertical characteristic of vegetation in a large scale. Previous studies often determined aerodynamic roughness using a minimization of cost function over MOS relationship or linear regression over it, traditional wind profile method, or remotely sensed vegetation index. However, these are complicated procedures that require a high accuracy for several other related parameters embedded in serveral equations including MOS. In order to simplify this procedure and reduce the number of parameters in need, this study suggests a new approach to extract aerodynamic roughness parameter from single or two heat flux measurements analyzed via Ensemble Kalman Filter (EnKF) that affords non-linearity. So far, to our knowledge, no previous study has applied EnKF to aerodynamic roughness estimation, while the majority of data assimilation study have paid attention to updates of other land surface state variables such as soil moisture or land surface temperature. The approach of this study was applied to grassland in semi-arid Tibetan Plateau and maize on moderately wet condition in Italy. It was demonstrated that aerodynamic roughness parameter can be inversely tracked from heat flux EnKF final analysis. The aerodynamic roughness height estimated in this approach was consistent with eddy covariance method and literature value. Through a calibration of this parameter, this adjusted the sensible heat previously overestimated and latent heat flux previously underestimated by the original Surface Energy Balance System (SEBS) model. It was considered that this improved heat flux estimation especially during the summer Monsoon period, based upon a comparison with precipitation and soil moisture field measurement. For an advantage of this approach over other previous methodologies, this approach is useful even when eddy covariance data are absent at a large scale and is time-variant over vegetation growth, as well as is not directly affected by saturation problem of remotely sensed vegetation index.

Calibration of aerodynamic roughness over the Tibetan Plateau with Ensemble Kalman Filter analysed heat flux

Baroni, G., Facchi, A., Gandolfi, C., Ortuani, B., Horeschi, D., and van Dam, J. C.: Uncertainty in the determination of soil hydraulic parameters and its influence on the performance of two hydrological models of different complexity, Hydrol. Earth Syst. Sci., 14, 251–270, doi:10.5194/hess-14-251-2010, 2010.; Beljaars, A. C. M., Schotanus, P., and Nieuwstadt, F. T. M.: Surface layer similarity under nonuniform fetch conditions, J. Clim. Appl. Meteorol., 22, 1800–1810, 1983.; Boulet, G. , Braud, I., and Vauclin, M.: Study of the mechanisms of evaporation under arid conditions using a detailed model of the soil-atmosphere continuum, J. Hydrol., 193, 114–141, 1997.; Chavez, J. L., Neale, C. M. U., Hipps, L. E., Prueger, J. H., and Kustas, W. P.: Comparing aircraft-based remotely sensed energy balance fluxes with eddy covariance tower data using heat flux source area functions, J. Hydrometeorol., 66, 923–940, 2005.; Chen, R. K. and Yang, C. M.: Determining the Optimal Timing for Using LAI and NDVI to Predict Rice Yield, J. Photogramm. Remote Sens., 103, 239–254, 2005.; Chen, Y., Yang, K., Zhou, D., Qin, J., and Guo, X.: Improving the Noah Land Surface Model in Arid Regions with an Appropriate Parameterization of the Thermal Roughness Length. J. Hydrometeorol., 11, 995–1006. doi:10.1175/2010JHM1185.1, 2010.; Choudhury, B. J. and Monteith, J. L.: A four-layer model for the heat budget of homogeneous land surfaces, Q. J. Roy. Meteorol. Soc., 114, 373–398, 1988.; Choi, T., Kim, J., Lee, H., Hong, J., Asanuma, J., Ishikawa, H., Gao, Z., Wang, J., and Koike, T.: Turbulent exchange of heat, water vapor, and momentum over a Tibetan prairie by eddy covariance and flux variance measurements, J. Geophys. Res., 109, D21106, doi:10.1029/2004JD004767, 2004.; De Bruin, H. A. R. and Verhoef, A.: A new method to determine the zero-plane displacement, Bound.-Lay. Meteorol., 82, 159–164, 1997.; Dunne, S. and Entekhabi, D.: An ensemble-based reanalysis approach to land data assimilation, Water Resour. Res., 41, W02013, doi:10.1029/2004WR003449, 2005.; Evensen, G.: Sampling strategies and square root analysis schemes for the EnKF, Ocean Dynam., 54, 539–560, 2004.; Foken, T. H. and Wichura, B.: Tools for quality assessment of surface-based flux measurements, Agr. Forest. Meteorol., 78, 83–105, 1996.; Goegebeur, M. and Pauwels, V. R. N.: Improvement of the PEST parameter estimation algorithm through Extended Kalman Filtering, J. Hydrol., 337, 436–451. 2007.; Jochum, M. A. O., de Bruin, H. A. R., Holtslag, A. A. M., and Belmonte, A. C.: Area-Averaged Surface Fluxes in a Semiarid Region with Partly Irrigated Land Lessons Learned from EFEDA, J. Appl. Meteorol. Clim., 45, 856–874, 2006.; Kohsiek, W., de Bruin, H. A. R., The, H., and van den Hurk, B.: Estimation of the sensible heat flux of a semi-arid area using surface radiative temperature measurements, Bound.-Lay. Meteorol., 63, 213–230, 1993.; Li, F., Crow, W. T., and Kustas, W. P.: Towards the estimation root-zone soil moisture via the simultaneous assimilation of thermal and microwave soil moisture retrievals, Adv. Water Resour., 33, 201–214, 2010.; Liu, H. and Foken, T.: A modified Bowen ratio method to determine sensible and latent heat fluxes, Meteorol. Z., 10, 71–80, 2001.; Liu, S., Li, S.-G., Yu, G.-R., Sun, X.-M., Zhang, L.-M., Hu, Z.-M., Li, Y.-N., and Zhang, X.-Z.: Surface energy exchanges above two grassland ecosystems on the Qinghai-Tibetan Plateau, Biogeosciences Discuss., 6, 9161–9192, doi:10.5194/bgd-6-9161-2009, 2009.; Ma, J. and Daggupaty, S. M.: Using All Observed Information in a Variational Approach to Measuring $Z_om$ and $Z_0t$, Am. Meteorol. Soc., 1391–1401


Click To View

Additional Books

  • Influence of Summer and Winter Climate V... (by )
  • Error Characterisation of Global Active ... (by )
  • Comparison of Empirical Models with Inte... (by )
  • Environmental Flow Assessments in Estuar... (by )
  • Virtual Laboratories: New Opportunities ... (by )
  • Spatial Rainfall Variability and Runoff ... (by )
  • Eagle 2006 – Multi-purpose, Multi-angle ... (by )
  • Persist: a Flexible Rainfall-runoff Mode... (by )
  • Catchment Classification: Hydrological A... (by )
  • Satellite Radar Altimetry for Monitoring... (by )
  • Polymer Tensiometers with Ceramic Cones:... (by )
  • Field Scale Variability of Solute Transp... (by )
Scroll Left
Scroll Right


Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.