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Initial release data, i.e. data no more than three months behind real time, is called ERA5T.
For the CDS, daily updates for ERA5T are available about 5 days behind real time and monthly mean updates are available about 5 days after the end of the month.
At the moment, the timing of the availability of the most recent ERA5T data on the CDS varies from day to day. Although it is not guaranteed, the D-5 data are typically available by 12UTC. We are working on reducing the variability of the time of availability.
For the CDS, ERA5T data for a month is overwritten with the final ERA5 data about two months after the month in question.
For MARS ERA5 data, monthly updates are available about two months after the month in question.
In the event that serious flaws are detected in ERA5T, this data the latter could be different to the final ERA5 data. Based on experience with the production of ERA5 so far (and ERA-Interim in the past), our expectation is that such an event would not occur often. So far, this it has only occurred once:
- for the months September, October, November and at least a part of December 2021, the final ERA5 product is and will be different from ERA5T due to correction of the assimilation of incorrect snow observations in central Asia. Although the differences are mostly limited to that region and mainly to surface parameters, in particular soil moisture, all the resulting reanalysis fields do differ slightly over the whole globe. On the CDS disks, the initial fields have been and will be overwritten, i.e., for these months, access to the original CDS disk, ERA5T product is not possible after it has been overwritten.
For the CDS, daily updates for ERA5T are available about 5 days behind real time and monthly mean updates are available about 5 days after the end of the month.
Note: At the moment, the timing of the availability of ERA5T data on the CDS on a daily basis can vary. We do not work to a specific target schedule. However, the D-5 data are typically available by 12UTC, but not guaranteed. We are working on reducing the variability of the time of availability, but this may take several months to achieve.
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- overwritten
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The IFS and data assimilation
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