DayMet and Harmony potential metadata issues

[mattwhuff]

Hello,

I've seen a few posts here about Harmony/DayMet issues and I'm having similar issues, so forgive me for potentially writing about an issue that is already known, but I wanted to share my own findings in case anyone else is having anything similar.

I first attempted to use the web interface for EDS, selecting specific granules over a 10 year period and bounding them using a bounding box. I then selected Harmony to subset spatially, and submitted the request. This failed, and I received the error:

75 percent maximum errors exceeded. See the errors fields for more details

I tried this a few more times, varying the number of granules I was asking for and using custom polygons, and they all failed in similar ways. Notably, at one point I tried using a shapefile to subset and while it loaded into EDS fine, Harmony did not give me the option to spatially subset when I went to create the job. I thought it might be a limit of the collection/Harmony to not be able to spatially subset complex shapefiles, however I have since found the following information when trying to learn more about the DayMet collection capabilities:

{"conceptId":"C2532426483-ORNL_CLOUD","shortName":"Daymet_Daily_V4R1_2129","variableSubset":false,"bboxSubset":true,"shapeSubset":true,"temporalSubset":true,"concatenate":false,"reproject":false,"outputFormats":["application/netcdf","application/x-netcdf4"],"services":[{"name":"sds/HOSS-geographic","href":"https://cmr.earthdata.nasa.gov/search/concepts/S2164732315-XYZ_PROV","capabilities":{"subsetting":{"temporal":true,"bbox":true,"dimension":true,"shape":true,"variable":true},"output_formats":["application/netcdf","application/x-netcdf4"]}}],"variables":[],"capabilitiesVersion":"2"}

Here, shape subsetting is set to true, but that may just be for custom polygons created in EDS. I have not tried to use a shapefile with harmony-py, which is what I turned to next.

I then moved to harmony-py to generate requests for jobs to see if anything was different or if I could get more complete error messaging.

Here's the code I used to create requests:

harmony_client = harmony.Client()

request = harmony.Request(
collection=harmony.Collection(id="C2532426483-ORNL_CLOUD"),
spatial=harmony.BBox(w, s, e, n),
temporal={
'start': dt.datetime.strptime('2023-01-01', '%Y-%m-%d'),
'stop': dt.datetime.strptime('2023-12-31', '%Y-%m-%d'),
},
format='application/x-netcdf4',
skip_preview=True,
)

I tried multiple different requests, some including all variables across the year requested, and some where I just tried to select specific granules in hope that I could get the individual granules I actually needed, since variableSubset seems to be set to False in the DayMet capabilities above.

Each time, they returned failed with the following error messages:


{'status': 'failed', 'message': 'WorkItem failed: nasa/harmony-opendap-subsetter:1.0.5: Subsetter failed with error: Projected variable "/lon" does not have an associated "grid_mapping" metadata attribute.', 'progress': 99, 'created_at': datetime.datetime(2025, 8, 22, 16, 28, 15, 770000, tzinfo=tzutc()), 'updated_at': datetime.datetime(2025, 8, 22, 16, 32, 29, 584000, tzinfo=tzutc()), 'created_at_local': '2025-08-22T09:28:15-07:00', 'updated_at_local': '2025-08-22T09:32:29-07:00', 'request': 'https://harmony.earthdata.nasa.gov/C2532426483-ORNL_CLOUD/ogc-api-coverages/1.0.0/collections/parameter_vars/coverage/rangeset?forceAsync=true&subset=lat(32.2%3A42.3)&subset=lon(-125%3A-113.5)&subset=time(%222023-01-01T00%3A00%3A00%22%3A%222023-12-31T00%3A00%3A00%22)&label=harmony-py&granuleId=G2951155427-ORNL_CLOUD&format=application%2Fx-netcdf4&skipPreview=true&ignoreErrors=true&variable=all', 'num_input_granules': 1, 'data_expiration': datetime.datetime(2025, 9, 21, 16, 28, 15, 770000, tzinfo=tzutc()), 'data_expiration_local': '2025-09-21T09:28:15-07:00', 'errors': [{'url': 'https://data.ornldaac.earthdata.nasa.gov/protected/daymet/Daymet_Daily_V4R1/data/daymet_v4_daily_na_vp_2023.nc', 'message': 'WorkItem failed: nasa/harmony-opendap-subsetter:1.0.5: Subsetter failed with error: Projected variable "/lon" does not have an associated "grid_mapping" metadata attribute.'}]}

Sometimes the error was /lon, sometimes it was /lat, and sometimes I got a 500 error like so:

{'url': 'https://data.ornldaac.earthdata.nasa.gov/protected/daymet/Daymet_Daily_V4R1/data/daymet_v4_daily_na_tmin_2010.nc', 'message': 'WorkItem failed: nasa/harmony-opendap-subsetter:1.0.5: Subsetter failed with error: 500 error retrieving: https://opendap.earthdata.nasa.gov/collections/C2532426483-ORNL_CLOUD/granules/Daymet_Daily_V4R1.daymet_v4_daily_na_tmin_2010.nc.dap.nc4'}]}

It looks like there may be an issue with the DayMet metadata that is making Harmony fail, or it's something else entirely that I'm not aware of and just generalizing off the error messages I received. Again, apologies if this is already known and being addressed, I just wanted to share in more detail for other users that may be experiencing issues and are unaware why.


Thanks,
Matthew

[ORNL - mthornton]

Hi Matthew,

Harmony access to Daymet_Daily_V4R1_2129 does not provide expected results and at this time should not be used.

The ORNL DAAC will be removing Harmony services reference to Daymet_Daily_V4R1_2129 if and until the issues can be resolved to avoid confusion.

I apologize for any inconvenience.

Best wishes,
Michele

Michele Thornton
Oak Ridge National Laboratory | Environmental Sciences Division
ESD | CCSI | DAAC | RSEI
1 Bethel Valley Road, MS 6301
Oak Ridge, TN 37830