Earthdata Forum

I am working with AU_SI12_NRT_R04 (https://cmr.earthdata.nasa.gov/search/concepts/C1886605827-LANCEAMSR2.html).

I noticed yesterday that CMR is reporting a granule of data that isn't actually available for download. I receive a 404 error when trying to access the resource, and the listing of published data (see here: https://lance.nsstc.nasa.gov/amsr2-science/data/level3/seaice12/R04/hdfeos5/) does not include the granule reported by CMR.

I'm wondering if this is an error with CMR or if the granule was not correctly published. The data file I'm trying to access is https://lance.nsstc.nasa.gov/amsr2-science/data/level3/seaice12/R04/hdfeos5/AMSR_U2_L3_SeaIce12km_R04_20231009.he5.

You can see this granule being reported in this query to CMR: https://cmr.earthdata.nasa.gov/search/granules.umm_json?page_size=500&short_name=AU_SI12_NRT_R04

I have saved the results of the above query as a PDF for upload as an attachment.

We noticed another issue with the data CMR is reporting available for this dataset.

Today, when I look at the CMR results, I see data files for 2024-02-14 listed on both servers. E.g., here are the "related-urls":

"RelatedUrls": [
{
"URL": "https://lance.nsstc.nasa.gov/amsr2-science/data/level3/seaice12/R04/hdfeos5/AMSR_U2_L3_SeaIce12km_P04_20240215.he5",
"Type": "GET DATA",
"Description": "Online access to AMSR-2 Near-Real-Time LANCE Products (primary)"
},
{
"URL": "https://lance.itsc.uah.edu/amsr2-science/data/level3/seaice12/R04/hdfeos5/AMSR_U2_L3_SeaIce12km_P04_20240215.he5",
"Type": "GET DATA",
"Description": "Online access to AMSR-2 Near-Real-Time LANCE Products (backup)"
},
{
"URL": "http://dx.doi.org/10.5067/AMSRU/AU_SI12_NRT_R04",
"Type": "VIEW RELATED INFORMATION"
}
],
"DataGranule": {
"DayNightFlag": "Both",
"ProductionDateTime": "2024-02-16T07:59:28.000Z",
"ArchiveAndDistributionInformation": [
{
"Name": "Not provided",
"SizeUnit": "MB"
}
]


---

The URL for the backup server (https://lance.itsc.uah.edu/amsr2-science/data/level3/seaice12/R04/hdfeos5/AMSR_U2_L3_SeaIce12km_P04_20240215.he5) results in a 404/Not Found error. Manually inspecting the listing for this server's files, I see that an R file is available for this day: https://lance.itsc.uah.edu/amsr2-science/data/level3/seaice12/R04/hdfeos5/AMSR_U2_L3_SeaIce12km_R04_20240215.he5.

My application programmatically uses CMR to select the most recent R files as input, falling back to a P file if the R file doesn't exist. This particular case results in the P file being used even though an R file is available because CMR does not report it.

Our SME investigated and does not see the discrepancy mentioned. There is only one file per day. The SME does see that the "P" file was replaced with "R' for 20240215 on the backup server but not the main server (note that CMR is populated by the main server code and those match). There must have been a transfer issue on 20240215 on the main server. And an issue on both the primary and back up systems on 20240214.

CMR query:
https://cmr.earthdata.nasa.gov/search/granules.umm_json?page_size=500&short_name=AU_SI12_NRT_R04
AMSR_U2_L3_SeaIce12km_P04_20240214.he5
AMSR_U2_L3_SeaIce12km_P04_20240215.he5
AMSR_U2_L3_SeaIce12km_R04_20240216.he5
AMSR_U2_L3_SeaIce12km_R04_20240217.he5
AMSR_U2_L3_SeaIce12km_R04_20240218.he5
AMSR_U2_L3_SeaIce12km_R04_20240219.he5
AMSR_U2_L3_SeaIce12km_R04_20240220.he5
AMSR_U2_L3_SeaIce12km_R04_20240221.he5
AMSR_U2_L3_SeaIce12km_R04_20240222.he5
AMSR_U2_L3_SeaIce12km_R04_20240223.he5
AMSR_U2_L3_SeaIce12km_R04_20240224.he5
AMSR_U2_L3_SeaIce12km_R04_20240225.he5
AMSR_U2_L3_SeaIce12km_P04_20240226.he5
AMSR_U2_L3_SeaIce12km_P04_20240227.he5

Primary server:
https://lance.nsstc.nasa.gov/amsr2-science/data/level3/seaice12/R04/hdfeos5/
AMSR_U2_L3_SeaIce12km_P04_20240214.he5
AMSR_U2_L3_SeaIce12km_P04_20240215.he5
AMSR_U2_L3_SeaIce12km_R04_20240216.he5
AMSR_U2_L3_SeaIce12km_R04_20240217.he5
AMSR_U2_L3_SeaIce12km_R04_20240218.he5
AMSR_U2_L3_SeaIce12km_R04_20240219.he5
AMSR_U2_L3_SeaIce12km_R04_20240220.he5
AMSR_U2_L3_SeaIce12km_R04_20240221.he5
AMSR_U2_L3_SeaIce12km_R04_20240222.he5
AMSR_U2_L3_SeaIce12km_R04_20240223.he5
AMSR_U2_L3_SeaIce12km_R04_20240224.he5
AMSR_U2_L3_SeaIce12km_R04_20240225.he5
AMSR_U2_L3_SeaIce12km_P04_20240226.he5
AMSR_U2_L3_SeaIce12km_P04_20240227.he5

Backup server:
https://lance.itsc.uah.edu/amsr2-science/data/level3/seaice12/R04/hdfeos5/
AMSR_U2_L3_SeaIce12km_P04_20240214.he5
AMSR_U2_L3_SeaIce12km_R04_20240215.he5
AMSR_U2_L3_SeaIce12km_R04_20240216.he5
AMSR_U2_L3_SeaIce12km_R04_20240217.he5
AMSR_U2_L3_SeaIce12km_R04_20240218.he5
AMSR_U2_L3_SeaIce12km_R04_20240219.he5
AMSR_U2_L3_SeaIce12km_R04_20240220.he5
AMSR_U2_L3_SeaIce12km_R04_20240221.he5
AMSR_U2_L3_SeaIce12km_R04_20240222.he5
AMSR_U2_L3_SeaIce12km_R04_20240223.he5
AMSR_U2_L3_SeaIce12km_R04_20240224.he5
AMSR_U2_L3_SeaIce12km_R04_20240225.he5
AMSR_U2_L3_SeaIce12km_P04_20240226.he5
AMSR_U2_L3_SeaIce12km_P04_20240227.he5

Kindly note that we provide NRT data as is. We cannot go back and republish the old data. If latency isn't an issue, then we recommend that the standard data is used.