On 18 April 2022, the IMS Daily Northern Hemisphere Snow and Ice Analysis (G02156) data set will have new file names. There are two updates being made to the file names:
- Addition of the timestamp to the file names for which the data are valid. This will affect all versions of IMS data (V1.1, V1.2, and V1.3).
- Update of the V1.1 and V1.2 files to be consistent with the way the V1.3 files are named, which will affect only V1.1 and V1.2 IMS data.
The current file names follow this convention: imsYYYYDDD_Xkm_vZ.z.asc.gz where YYYYDDD is the 4-digit year and 3-digit day of year, Xkm is the resolution (1km, 4km, or 24km), and vZ.z is the version number (v1.1, v1.2, or v1.3). For update #1 that affects all versions, the new file names will have a UTC time code added to them as follows: imsYYYYDDD_00UTC_Xkm_vZ.z.asc.gz The 00UTC indicates that the data are valid at 0:00 UTC for the date in the file name. For update #2, the V1.1 and V1.2 files will have their date incremented by one day so that the file name reflects the date for which the data are valid, instead of when they were created. For example, if the date is currently 2009245 then it will get updated to 2009246. This change is being made so that V1.1 and V1.2 file names are consistent with V1.3, which already use the date for which the data are valid. It is also the more appropriate date to use because IMS data are nowcasted. A file name that reflects when the nowcast is valid is more usefully descriptive than a file name that reflects when the file was created. A nowcast is a detailed analysis of the current weather or surface conditions that are then forecasted for a period from 0 to 6 hours into the future.
For further details see https://www.sciencedirect.com/topics/earth-and-planetary-sciences/nowcasting.
Data set DOI: https://doi.org/10.7265/N52R3PMC