Problem with Dimensions of Variables - GoM 1/25 Analysis Hindcast

[Michael Gray]

Hello,

I was accessing the Gulf of Mexico Analysis Hindcast data (https://tds.hycom.org/thredds/dodsC/GOMu0.04/expt_90.1m000/data/hindcasts/2022.html) via xarray in Python and noticed when I subset data, I do not receive any values for water_u and water_v.

If you use the OPenDAP Query Form to select these variables, the auto-generated URL returns indices [0:1:0] [0:1:0] [0:1:0], which leads to empty arrays. I also noticed the documented dimensions of water_u and water_v on the OPenDAP Query Form are incorrect- it suggests dimensions of (1, 20, 173, 271) which do not correlate with the lengths of time, depth, lat, and lon in the same dataset. Accessing the data using these indices gives improper data as well.

I was able to successfully pull in water_u and water_v variables by indexing them with the dimensions of the time, depth, lat, and lon matrices, but this was not immediately obvious to me.

I don't know if this is on purpose or not, but it stuck out as an error to me.