ERA5_Land and ERA5 snow data differences

Dear Joana,

Snowfall in ERA5 is accumulated since the previous archiving ie in the last hour (3 hours for the ensemble), whereas in ERA5-Land it is accumulated from the beginning of the forecast, which will be responsible for large differences in the two datasets.

A possible reason for large differences in snow depth, could be the different resolution. Glaciers have a specified snow depth of 10m, so the different locations of the edge of the glaciers could give rise to large differences in the snow depth. I can't say definitely whether this is the cause of what you find because I can't see your images.

Regards,

Paul

Thank you Paul,

I've de-accumulated snowfall, and they are now pretty close, some differences, but as expected from diff products.

Snow depth is still pretty different, I am attaching the snow depth again hoping you can see it 

Many Thanks

J

Dear Joana,

I can see your snow depth now. I presume the x axis is labelled in hours, is that correct?

Thanks,

Paul

Dear Joana,

The increases in snow depth tie in with the snowfall events, at least to some extent. If there's a disparity in the magnitude, then rainfall that freezes on the ground might account for the disparity. Can you check how large the disparity is, if any?

Thanks,

Paul

Dear Joana,

Given you said the snowfalls are now similar, there must be a disparity between the snowfall accumulation and the snow depth in at least one of the two datasets. Do you know which dataset has the largest disparity?

Thanks,

Paul

Dear Joana,

I'm not sure what you have calculated in the workbook - could you explain?. What I was thinking of was to calculate the change in snow depth from one time to the next and compare that with the snowfall during that period eg over each hour. The large snowfall events should tie in with the changes in snow depth to some extent, though rain can freeze when it hits the ground and snow can melt too.

Thanks,

Paul