Ridiculous Request Limits Disregarding Grid Resolution

Datasets and Usage C3S - Datasets and Usage
1

I understand that imposing limitations on each request can help improve system performance. However, it seems that the grid size is not being taken into account when determining these limits.

On the website, there is currently no option to specify the grid size. (But the old system has this option.) For example, a variable with 31 days and 36 pressure levels is considered as 1,147 units, with a spatial resolution of 0.25deg. This exceeds the limit for “post-processed daily datasets”. When I attempted to download the data via the API, I specified a coarser resolution of 1deg, yet the system still flagged my request as exceeding the limit. (The size of the file )

Could you explain why grid resolution is not taken into account when calculating request limits? Given its significant impact on data volume, overlooking this factor seems unreasonable.

1 Like
2

Agreed. It would be nice if this could be taken into account.

I routinely want to get ERA5-land data for 1-2 years and have it refused for ‘Request too large’, even though I am only requesting for a very small region (5° x 5° at most).

3

What about downloading separate vertical levels and/or different timestamps in different requests?
I think that it is best to separate different time stamps first, then levels and so on, but perhaps this is applicable only to data on MARS, not on the CDS. Anyway, separating your request in smaller ones will help.
There is a performance tips page with recommendations, have you seen it?:

There is a page