co2usa_download_netCDF.r

# Code to automate the download of CO2-USA Synthesis netCDF data from the ORNL DAAC:
#
# Step 1: Visit the CO2-USA archive on the ORNL DAAC:
# https://doi.org/10.3334/ORNLDAAC/1743
# 
# Step 2: Sign into your account (or create one if you don't have one) 
#
# Step 3: Click on "Download Data" to download the entire data set in a zip file. 
#
# If you want to download part of the data set, follow these optional steps:
#
# Step 4: Select the data files you want to download, put them in your
# cart, and select "Order These Items" from your cart.
#
# Step 5: The ORNL DAAC will send you an email with a location where you can
# download the data.  They give you several options to download the data,
# and the following code is one additional option for you to download the
# data.
# 
# Step 6: Copy your download token in the email from the ORNL DAAC and past it below:
# For example: 'aun26r81235cr3h4c3v9y1g32t22646g'
download_token = '<your_ORNL_download_token>' # PUT IN YOUR DOWNLOAD TOKEN ISSUED FROM ORNL

# Step 7: Choose the location on your computer to save the data:
download_location = file.path('C:/Users','u0932260','gcloud.utah.edu','data','co2-usa','synthesis_output_ornl')
if (!dir.exists(download_location)) mkdir(download_location)
setwd(download_location)

# Step 8: The rest of the code will download the data for you:
hyperlinks = readLines(paste('https://daac.ornl.gov/orders/',download_token,'/download_links.html',sep=''))
hyperlinks = hyperlinks[grep(pattern='<a href=".*?.nc">',hyperlinks)] # indices of the lines with valid hyperlinks
hyperlinks = gsub(pattern='<li><a href="',replacement='',hyperlinks)
hyperlinks = gsub(pattern='\">.*</li>',replacement='',hyperlinks)
for (i in 1:length(hyperlinks)) {
  filename = substr(hyperlinks[i],regexpr('/data/',hyperlinks[i])+6,nchar(hyperlinks[i]))
  print(paste('Downloading',filename))
  download.file(hyperlinks[i],file.path(download_location,filename),mode='wb')
}
print('Done downloading the CO2-USA synthesis data from the ORNL DAAC')
rm('download_location','download_token','hyperlinks','filename')