monocongo/climate_indices

To which period does the calculated SPI refer to?

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greenfrog203 commented

Hi James,

just to make sure I am right:
I opened the provided example netCDF-Files in ArcMap. (I use the Tool "Make NetCDF Raster Layer".)
I can choose monthly values. For example, if I choose 01/07/2010 at SPI at 6-month scale, I assume the SPI for 01/07/2010 is calculated by the prcp-data from the last six months, thus from 01/Jan/2010 to 01/July/2010 - is this correct? If not, please correct.
Hope I was able to point out what my question is.
Thanks again in advance!

Green Frog

monocongo commented

Yes, this is correct. Or almost, as the value for July 2010 will be computed using the six previous months, including July, so Feb 2010 - July 2010. For example, if you choose to compute 3-month scale then the first two months will not have a value, as the first available month for a computed value will be the third month. I hope this helps!

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