README

VPRMLandSfcModel-package   package:VPRMLandSfcModel    R Documentation

R implementation of VPRM with parameter estimation

Description:

     Provides an R implementation of the Vegetation Photosynthesis and
     Respiration Model (VPRM) of Mahadevan et al (2008) and tools to
     estimate VPRM parameter values from observations.  VPRM is a
     simple diagnostic land surface model based on light-use
     efficiency.  VPRM diagnoses gross ecosystem exchange (GEE) of
     carbon dioxide, ecosystem respiration (R), and net ecosystem
     exchange (NEE) of carbon dioxide.  VPRM parameters may be
     estimated separately for different subsets of a dataset of
     observations.  If the Rmpi package is installed, such separate
     parameter estimations may be run in parallel.

Details:

       Package:   VPRMLandSfcModel
       Type:      Package
       Version:   1.2
       Date:      2015-04-02
       License:   GPL-3
       LazyLoad:  yes

     The literature in the references section provides a detailed
     description of VPRM.

     The top-level function for running VPRM is vprm_calc_NEE.
     vprm_calc_NEE calculates net ecosystem exchange (NEE) according to
     the VPRM (Mahadevan et al (2008) eqn 12).

     The top-level function for estimating VPRM parameters from
     observations is estimate_VPRM_pars.

     The other functions provide methods to obtain the necessary driver
     data and to calculate some of the intermediate quantities that
     VPRM derives from remote sensing observations (e.g. land surface
     water index, Tscale, Pscale, etc.).

     The package includes two datasets:

     Park_Falls contains ground-observed as well as satellite-observed
          driver data for VPRM from the Park Falls, Wisconsin, USA
          Ameriflux site.

     VPRM_parameters contains values for VPRM parameters lambda, PAR_0,
          alpha, and beta.  The parameter values were determined by
          optimizing VPRM using 65 North American eddy covariance sites
          as described in Hilton etal (2013).

Author(s):

     Timothy W. Hilton

     Maintainer: Timothy W. Hilton <thilton@ucmerced.edu>

References:

     To cite the Vegetation Photosynthesis Respiration Model (VPRM)
     itself, use:
     Mahadevan, P., Wofsy, S.C., Matross, D.M., Xiao, X., Dunn, A.L.,
     Lin, J.C., Gerbig, C., Munger, J.W., Chow, V.Y., and Gottlieb,
     E.W., 2008. A satellite-based biosphere parameterization for net
     ecosystem CO2 exchange: Vegetation photosynthesis and respiration
     model (VPRM). Global Biogeochemical Cycles, 22, GB2005.
     doi:10.1029/2006GB002735.

     To cite the R package 'VPRMLandSfcModel', use:
     Hilton, T. W., Davis, K. J., Keller, K., and Urban, N. M.:
     Improving North American terrestrial CO2 flux diagnosis using
     spatial structure in land surface model residuals, Biogeosciences,
     10, 4607-4625, doi:10.5194/bg-10-4607-2013, 2013.