The files under this data/icon/l2 directory were modified by the SPDF.
1) the file names were changed to be all lowercase and the dates were changed from yyyy-mm-dd to yyyymmdd
2) the internals were changed so that all Epoch dimensions are now "Unlimited" and the chunking size was improved.
3) temporarily, the l2-4_fuv_day files are unavailable to users for download due to an error in variable names for almost all files in year 2021.  As soon as we receive reprocessed/corrected files, the directory will be available again.
TJK 1/28/2021
TJK #3 added on 12/21/2022