This is a step-by-step walkthrough explaining how to download
NARCCAP data from the Earth System Grid data portal. To download
- Go to the Earth System Grid homepage, http://www.earthsystemgrid.org/.
- From the "Home" tab, click the NARCCAP logo or link in the middle
of the page.
- NARCCAP data is organized by model and driver. The top-level
catalog page for NARCCAP shows a grid with RCM along the vertical axis
and driver (GCM or NCEP reanalysis) along the horizontal axis. Click
the "data" link of the RCM/driver combination you're interested in.
- At the next level, data files are organized by variable into
tables (groups). See the data tables
page to find which table contains the variable you are interested in.
For example, if you want surface temperature data, you want variable
tas from Table 2. Note that primary impacts-assessment
variables are all in Table 2. Click the appopriate link.
- Click the "Download File" link.
- The wget script and DML script options on the next page are for
downloading all files in that table. Most users will want only a
subset of the available variables, so click the "Download individual
files" button down at the bottom.
- The page will list individual datafiles. To download a file,
click the "download" link in the rightmost column.
- If you want to download multiple files using wget, select the
files using the checkboxes (you may find the subselection panel to the
left helpful), then click the "Download ALL Selected File(s)" button
at the top of the page. Then click the download icon next to "WGet
Script Download" to download a wget script. If you don't have wget,
click the "DML Script Download" icon to get a script for downloading
data using DataMover-Lite, a Java-based program you can launch from
Note: Most MacOS and linux systems have wget installed. You can
download and install wget on a windows machine. DML should work on
any system with Java installed, which is most of them. N.B. that the
download authentication in the scripts will only last for about a day,
so you can't re-use the script to download the data again at a later
The datafile names look like this:
Each file contains data for a single variable for 5 years, ending
in a year that ends in 0 or 5. (Files covering the beginning and
ending of the run may not contain a full five years of data.)
VarName is the IPCC/CF-convention Variable Name
as listed in the data tables
ModelName is the 4-character RCM identifier
DriverName is "NCEP" or the name of the driving GCM
Time is the starting time of the file, in the form
So, for example,
data for variable
tas from the RegCM3 regional model
driven with NCEP boundary conditions starting at 03 UTC on January
1st, 1981 and ending at 00 UTC on January 1st, 1985.
3-D data (from Table 5) is separated into levels. The pressure
height of the level in hPa is indicated in the filename between the
driver and the time:
contains data at the 750 hPa pressure height.
Note that you very likely do not want to download the first file in
each dataset. See the Time Periods
Covered page for information about the spin-up period and why you
probably don't want to use data from it.