Introduction

An update of the mars keys is required to be able to support some new products within the MARS catalogue that underlies the Emergency Warning Data Store fire danger indices datasets.
Preparations are underway to migrate the data into a new structure. While this work is on going, there will no longer be updates to this dataset until further notice.

The dataset will remain available until the ingestion of the data into the new tree structure is complete.

What is not changing?

Once the ingestion of data into mars is complete, the data values will be identical to the existing data that has previously downloaded.

What is changing?

The internal structure of MARS is changing. While this is abstract to users of the CDS, it does require removing the current data in order to ingest it with a different design.

There will also be changes to some of the keys that you see within the Grib files.

Timespan is a new key, which is not used within the Fire grib's.

Fire outputs of the GEFF model use the localtime design for creating the outputs, which reflects the number of forecasts and fields used as inputs to create the forcing fields

One difference is the origin and the forcing field which have changed slightly, to indicate the forcing used in the model.

This will also be relevant to the IFS cycle used in the operational GEFF Output, Seasonal outputs and the future ERA6 outputs.

This is the output of grib_ls -m for the new and old structures.

domain      expver      class       type        stream      model       origin      levtype     date        time        step        param       
g           0001        gw          fc          oper        geff        ecmf_ea     sfc         19400103    0000        12          260540     

domain      expver      class       type        stream      model       levtype     date        time        step        param       forcing     timespan    
g           9999        gw          fc          oper        geff        sfc         19400103    0000        12          260540      era5        none      

The model version can also be seen with grib_ls, which was not the case in the past.

Why is it changing?

The changes are necessary to support new grib encoding as part of the Grib2 Migration work as well as supporting new parameters that are not yet available in MARS.

How long will it take?

Data is already being prepared, we estimate it will be a few weeks before we have retrieved all the data out of MARS.
Once data has been retrieved, the existing data will be removed. At this point the dataset pages will be made unavailable.

At that point, the configuration will be updated and new data will begin to be archived almost immediately.
EWDS pages will be available once again, however the data will not be visible to the EWDS immediately and may take a few days for all previous data to reappear within the EWDS.