Temperature and NDVI availability


#1

Hi,
I was wondering if there are any plans to expand the time span of the air temperature and precipitation data set provided by ERA5. So far it only dates back to 2002 in the data cube, whereas ERA5 actually provides data starting from 1979. For preciptitation there is another data set available (provided by GPCP), however there is only one air temperature data set to my knowledge.
Furthermore, I encountered that in the colombian data cube, NDVI and EVI from MODIS are available. Is there a possibility to include these data sets also into the global cube? The original MODIS NDVI data set has a 16-day resolution, as far as I know. Therefore, was the data duplicated to fit the 8-day resolution of the data cube or how was this handeled?


#2

You are right. The main reason is that when we started processing the data, it was available only from 2002. I will reprocess the data now that it is available for the full time span so that we can include it in the next version of the data cube.

Yes, there we simply repeated the 16daily values to fit the 8daily time resolution. The main reason to include NDVI in the colombian cube was because they needed something which is available at 1km.

In the global data cube our approach was from the beginning to focus on global datasets with physical meaning, instead of using spectral band indices. So I would suggest to use the FAPAR product from QA4ECV instead if you need something describing “greenness”, or is there some reason that this is not suitable?


#3

Thank you very much for your quick response.
Do you have a rough estimate when the next version of the data cube will be available?
I think the FAPAR product is suitable for me, I was just interested to also use the NDVI as it is a very common measure, but I don’t rely on it.


#4

I started the re-processing of the ERA5 data now and will let you now when it is done.