Provides an R implementation of the Vegetation Photosynthesis and Respiration Model (VPRM) of Mahadevan et al (2008), the urbanVPRM of Hardiman et al (2017), 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. The urbanVPRM adapts the VPRM to urban settings by adjusting GEE and R to account for impervious surface area and the urban heat island effect. (urban)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.
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:
library('devtools')
install_github('Timothy-W-Hilton/VPRMLandSfcModel')
The vignette document 'VPRM_vignette', included with the package, provides several "getting started" usage examples.
library('VPRMLandSfcModel')
RShowDoc('VPRM_vignette', package='VPRMLandSfcModel')
Timothy W. Hilton
Maintainer: Timothy W. Hilton t.hilton@gns.cri.nz
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 urban Vegetation Photosynthesis Respiration Model (urbanVPRM) use
Hardiman, B. S., Wang, J. A., Hutyra, L. R., Gately, C. K., Getson, J. M., & Friedl, M. A. (2017). Accounting for urban biogenic fluxes in regional carbon budgets. Science of The Total Environment, 592, 366–372. https://doi.org/https://doi.org/10.1016/j.scitotenv.2017.03.028
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.