Hi, I'm an error. x

R script to calculate daily PAR from solar radiation data

Authors: Sandra Villamizar
Owners: Sandra Villamizar
Resource type:Generic
Created:Jun 03, 2016 at 2:32 p.m.
Last updated: Jun 11, 2016 at 2:05 p.m. by Sandra Villamizar


Generating estimates of daily reference photosynthetically Active Radiation (PAR). We show the procedure to generate estimates of daily reference PAR using solar radiation data. The input for the R script (CalculateDailyPAR.R) is a raw time series of hourly solar radiation (stored in variable ‘ws’) that for our case was obtained from the CIMIS website (station id: 105) [California Department of Water Resources, 2015]. The script processes the data set to format the date and time columns, and to identify missing data points reporting their position within the time series (variable ‘na.id’). The user fills the gaps using adequate strategies and creates a new input file (stored in variable ‘fill.points’) containing the values to fill in within the time series. A reference PAR estimate is obtained as a constant fraction of solar radiation using the conversion factor proposed by [Meek et al., 1984]. The script then calculates an average daily value of solar radiation and integrates the reference PAR over the daytime period to obtain a daily value. The script ends by generating a final table (‘ws.results’) reporting daily values of solar radiation (maximum and mean in W m-2), and maximum, mean, and minimum reference PAR values in units of (μmol m-2 d-1) and (mol m-2 d-1).

Subject Keywords

R script,Solar Radiation,Photosynthetically Active Radiation

How to cite

Villamizar, S. (2016). R script to calculate daily PAR from solar radiation data, HydroShare, http://www.hydroshare.org/resource/29c5ce6c1f3146538d252bc15ad5a976

This resource is shared under the Creative Commons Attribution CC BY.


Sharing status:

  • Public Resource  Public
  • Sharable Resource  Shareable


Download All Content as Zipped BagIt Archive
Learn more about the Bagit archive format


The people or organizations that created the intellectual content of the resource.

Name Organization Address Phone Author Identifiers
Sandra Villamizar Universidad Pontificia Bolivariana, Bucaramanga Km 7 vía a Piedecuesta, Santander, Colombia


Be the first one to  +1 this.  (You need to be logged in to rate this.)


There are currently no comments

New Comment