MERRA automatic Access
|Last update: Jan. 2018|
- 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
SoDa_MERRA-2_Carpentras.csvoutput file (Windows environment). Rename the text file with a .sh extension and run it using >my_script.sh in a Unix environment.
The WGET command in details
SoDa_MERRA_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
time_step: "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.
Identical to the output columns received via the MERRA-2 Web interface
Recommendations - other links
Warning! It is strongly recommended to avoid the launch of parallel requests, using the "&" at the end of each wget request line. This would endanger our system.
More info about:
- Error messages
- FAQ ("I don't receive the output file!", "How can I launch automatically my requests every night", ...)
You can also automatically retrieve MERRA-2 dataset by using the CURL command as follows:
curl -f -s -S -F firstname.lastname@example.org -o output_merra-2
_curl.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 MERRA-2 but are needed for the CURL request.
Please note that curl output does not contain headers.