CERA-20C: Notes, Questions, and Discussion
Quick overview and useful links
All 10 members are available at, e.g., http://apps.ecmwf.int/datasets/data/cera20c
Be sure to "Select number" of member 0 to member 9 (or get them all).
Direct dataset questions to ECMWF User Support https://climate.copernicus.eu/help-support
General Reanalysis Notes, Questions, and Discussion
precipitation cera20 c reanalysis
I downloaded an edmo dataset of the cera-20c model of 1 model ensemble. I want to convert these data, which are in [m] to mm/month. Further specifications: 0.125/0.125 grid, -29/30/-30/31 area. Example of the data (see Attachment) of total precipitation January 1980:
0.00972608 0.00957544 0.00941561 0.00924491 0.00906292 0.00886799 0.00865884 0.00843403 0.00819166 0.01005578 0.00989428 0.00971898 0.00952822 0.0093197 0.00909092 0.00883853 0.00855918 0.00824787 0.01038548 0.01021917 0.01003489 0.00982972 0.0096001 0.00934102 0.00904642 0.00870878 0.00831765 0.01071518 0.01055033 0.01036417 0.01015189 0.00990765 0.00962391 0.00928983 0.00889097 0.00840687 0.01104488 0.01088818 0.01070745 0.01049622 0.01024633 0.00994609 0.00957837 0.00911808 0.0085245 0.01137458 0.01123292 0.01106578 0.01086541 0.01062116 0.01031674 0.00992645 0.00940829 0.00868705 0.01147842 0.01135348 0.01120367 0.01102044 0.01079165 0.01049747 0.01010488 0.00955559 0.00619612 0.01088233 0.01076115 0.01061573 0.01043772 0.01021541 0.00992938 0.00954828 0.00901466 0.00575109 0.01028645 0.01016882 0.01002758 0.00985479 0.00963917 0.00936149 0.00899168 0.00546506 0.00530627
My method: Taking the average of these numbers multiplying by 31(days) and 1000 (to mm ) gives me 289 mm for January. But this does not seem right. I hope you can provide me with the right answer.
Thanking you in advance.
Louwrens Timmer
Hi Louwrens, Gil forwarded…
Hi Louwrens,
Gil forwarded your question to ECMWF who produced the data set. I don't have the answer, but ECMWF has a user support for the reanalysis products including CERA-20C. Just go to this webpage https://climate.copernicus.eu/help-support and contact them.
Which value would you expect? To know whether this issue is coming from the data set or the way you process it I would suggest to look at precipitation over Europe on a recent month where we have more observations. Bear in mind that CERA-20C does use only pressure and wind measurements to produce the analysis.
Patrick.