MERRA-2 automatic Access
|Last update: February 2021|
Warning! It is strongly recommanded to avoid the launch of parallel requests, using the "&" at the end of each wget request line. This would endanger our system.
- Download wget.exe in a directory (Windows environment - by default available in Unix)
- In the same directory, create a text file and copy-paste in a single line the following instruction to test this permanent access to Carpentras, France:
- Rename the text file with the .bat extension and double click on the .bat file to retrieve the
.csvoutput file (Windows environment). Rename the text file with a .sh extension and run it using >my_script.sh in a Unix environment.
WGET, in details
wget -O output.csv --header="soda-user: your_login" --header="soda-passwd: your_password" ...
your_password: this access is restricted to registered users, i.e. to users who purchased an automatic access to the data. Please contact us for a quotation or to receive your SoDa automatic access credentials
server: "www.soda-is.com" (main server) or "pro.soda-is.com" (mirror server)
longitude: in degrees, with at least 3 digits after comma, e.g. "geopoint=45.563,7.25"
yyyy-mm-dd: the first day and last day of your request, from 1980 up to about a month ago. The available shortcuts to use for first and last days of the requests are: d, d-x, d+x, m, m-x, m+x, y, y-x, y+x with "x" representing numerical value, "d" = day, "m" = month, "y" = year
time_step: "1", "5", "10", "15" (minutes), "h" (hourly), "d" (daily), "m" (monthly). Automatic requests with a time step below 10 min are limited to one month, and automatic requests with a time step below one day limited to one year (identical to HelioClim-3 automatic request behavior).
Time reference is Universal Time.
Outputs: Identical to the output columns received via the MERRA-2 Web interface
You can also automatically retrieve MERRA-2 dataset by using the CURL command.
Beware the dates!!! MERRA data are available from 1985 up to a month ago.
Note that output csv files retrieved via the CURL command does not contain header.
curl -f -s -S -F firstname.lastname@example.org -o output.csv --header "soda-user: guest" --header "soda-passwd: guest" http://pro.soda-is.com/pub/merra2_request.php
With the following stations.txt file format:
# id: station name
# latitude and longitude: in degrees, with at least 3 digits after comma
# elevation: ignored
# time reference: ignored
# duration: "15" (minutes), "h" (hourly), "d" (daily) or "m" (monthly)
# firstday and lastday: first and the last days of the request, expressed as yyyy-mm-dd
# slope of panel: ignored
# azimuth of panel: ignored
# ground_albedo: ignored
# horizon: ignored (optional)
# calibration: ignored (optional)
# format: ignored (optional)
#id lat lon elevation time duration firstday lastday slope azimuth albedo
Carpentras1 44.083 5.059 -999 UT d 1985-01-01 1985-01-31 0 0 0.2
Carpentras2 44.083 5.059 -999 UT h 1985-01-01 1985-01-05 0 0 0.2
NB: stations.txt is voluntarily identical to the one used to automatically retrieve satellite-derived solar radiation datasets HelioClim-3. Of course, a few parameters are not used to run this service but are needed for the CURL request.