GPP MYD17A2HGF units 8day

[claragl]

I have a concern regarding the `statistics_Gpp_500m.csv` file. Specifically, does the column "mean" correspond to the daily GPP data (in kgC/m²), or is it the cumulative value over 8 days?

[LP DAAC-EDL - lien]

Hello,
The mean would be for the 8-day data sets, not the individual days within the 8-day products. Please let us know if you have any questions.
Thanks,
Brett

[claragl]

I have data from an eddy covariance tower in cereals with a range of daily GPP values around 0-30 gC m-2 d-1 for the entire year. When I compare it with the MODIS MYD17A2HGF data, it follows the same pattern; however, the MODIS data are 0-4 gC m-2 d-1 (when I divided the 8-day product data by 8 each day data to obtain daily values). On the other hand, if I do not divide the 8-day data by 8 and leave them as they are, they fit better with my tower data. Therefore, if I follow data recommendations there is a considerable daily bias regarding Eddy data. Hence, could you confirm me that data contained by GPP MODIS images (i.e. MYD17A2HGF.A2014073.h17v05.061.2022078013949_Gpp_500m.tif) needs to be divided by 8 to obtain daily data?

Thanks in advance

[LP DAAC-EDL - lien]

Hello,
I don't believe it would be advisable or accurate to divide by 8. It is probably unlikely that each day of the 8-day period had the same GPP value. So, it would be best to leave it as 8-day cumulative.
Thanks,
LPDAAC