vpRm

Version 0.0.0.9003 "Phoenix canariensis"

Introduction

VPRM (Vegetation Photosynthesis Respiration Model) is a model of NEE (Net Ecosystem Exchange) (Mahadevan et al 2008). This R package handles the driver data and calculations to run a VPRM model

Goals

This package should:

• Provide a single wrapper function to run VPRM within CONUS (eventually global).
• Be modular and tolerant of different sources/forms for driver data. If a new source for driver data is desired, it should be possible to slot in a new script for importing that data with minimal reconfiguration of the rest of the code.
• Be semi-robust. I am a grad student, and this is one part of my research, but it should be useful to people with different computer systems than me within a reasonable amount of work.

Getting Started

This package is not yet hosted on CRAN. In order to install, if the R package devtools is not installed, install it:

Rscript -e 'install.packages("devtools")'

Then, clone this repository:

git clone https://github.com/BlueGrisGris/vpRm.git

Then, navigate into the vpRm directory, and call install() from devtools to install the package into your library.

cd vpRm
Rscript -e 'devtools::install()'

This will install the vpRm package. Now, to begin running VPRM models, the following driver data are required, and can be downloaded from a variety of sources:

• Photosynthetically Available Radiation (PAR) or Downwelling Shortwave Radiation (SDR)
• Temperature at 2 meters above the surface
• Enhanced Vegetation Index (EVI)
• Landcover type
• Greenup and Greendown days for each pixel
• Minimum and Maximum EVI data for the year (Or a full year's worth of EVI data)

To initialize an object of class vpRm in R, supply the filenames of your driver data to the new_vpRm() function:

my_vpRm <- new_vpRm(
	vpRm_dir
	, lc_dir
	, isa_dir
	, temp_dir
	, par_dir
	, evi_dir
	, evi_extrema_dir
	, green_dir
)

Next, process the driver data:

proc_drivers(my_vpRm)

Finally, run the model:

run_vpRm(my_vpRm)

Version Information

Version 0.0.0.9003 "Phoenix canariensis"

• Rewrite Codebase to vectorize processing of hourly driver data and VPRM calculation independently of terra multilayer calculations

Version 0.0.0.9002 "Thuja plicata"

• Fixes to correct VPRM results

Version 0.0.0.9001 "Ficus rubiginosa"

• Implement simple interface to run VPRM over a predetermined spatial-temporal domain (for example, a STILT output)
• Implement processing 2D and 3D driver data to a format that can be fed into a VPRM model
• Implement S3 class "vpRm", along with methods to:
  • Process all driver data
  • Run a VPRM model

Version 0.0.0.9000 "Picea pungens"

• No minimum viable soluton

Goals for future versions:

• Simple R/vpRm interface for downloading driver data
• Wrapper function to run VPRM models in a single line