RC for HadISDH-land-4-6-1-2024f

[Kate-Willett]

1. source_id['source_id'][key]['source_name'] = 'HadISDH.land.4.6.1.2024f'
2. source_id['source_id'][key]['release_year'] = '2024'
3. source_id['source_id'][key]['source_description'] = 'HadISDH land near-surface humidity anomalies'
4. source_id['source_id'][key]['source_version_number'] = '4.6.1.2024f'
5. source_id['source_id'][key]['institution_id'] = 'MOHC'
6. source_id['source_id'][key]['region'] = 'global_land'
7. source_id['source_id'][key]['source_type'] = 'gridded_insitu'
8. A list of CMIP variable_ids that the above information refers to. In most cases it will only be for one variable_id. If it is for more than one, please make sure your source_description is sufficiently general to apply to all relevant variable_ids.
   huss
   hussanom
   hurs
   hursanom

Questions:
a) cf units for specific humidity and relative humidity are both 1. I've no idea why this is. It should be kg/kg for specific humidity and %rh for RH. Not something we can change but it makes me grumpy.

b) hussanom/hursanom - I think these should be both the input and output names. In your current version of obs4MIPs_Amon.json the output name is still huss for hussanom which I think will create an identically named file to huss and some confusion. I have changed this in my branch but it will need to be edited in the code used to create the obs4MIPs_Amon.json files.

c) hussanom/hursanom - how can we store information about the climatological period? For HadISDH this is 1991-2020 but it will differ for other datasets and is important for uses. There is a 'climatology' attribute for time and 'climatology_bounds' (see 7.4 https://cfconventions.org/cf-conventions/cf-conventions.html#climatological-statistics) but this may not be quite the right usage. Its not clear if time can have other attributes. Perhaps it could look something like:

month = 12 ;
characters = 10 ;
latitude = 36 ;
longitude = 72 ;
bound_pairs = 2 ;
variables:

dimensions:
time=624;
month = 12 ;
latitude = 36 ;
longitude = 72 ;
bound_pairs = 2 ;
variables:
float hussanom(time, lat, lon);
hussanom: long_name="near-surface specific humidity anomaly";
hussanom: cell_methods="time: difference from climatological mean over month and years area: mean over gridbox";
hussanom: units="1";
float time(time);
time: standard_name = "time" ;
time: long_name = "time" ;
time: units = "days since 1973-1-1 00:00:00" ;
time:axis = "T" ;
time: calendar = "gregorian" ;
time: start_year = 1973 ;
time: end_year = 2024 ;
time: start_month = 1 ;
time: end_month = 12 ;
time: bounds = "bounds_time" ;
time: climatology="climatology_bounds";
int bounds_time(time, bound_pairs) ;
bounds_time: standard_name = "time" ;
bounds_time: long_name = "time period boundaries" ;
int climatology_bounds(months, bound_pairs); # these could be characters for datetime format?
climatology_bounds: long_name = "climatological monthly means over 30 year period"
data: // time coordinates translated to datetime format
climatology_bounds="1991", "2020",
"1991", "2020",
"1991", "2020",
"1991", "2020", etc ;

d) The license in obs4MIPs_CV.json only gives Creative Commons license option. HadISDH (and other MOHC datasets) are under Open Government Licences (OGL). I think we need to be able to use this:
"license":"Data in this file is licensed under an Open Government Licence (https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/)",

e) How to store additional info - uncertainty, actual values, the climatology fields etc...

[gleckler1]

@Kate-Willett A first attempt to get this RC content in the master branch as well as adding the two anomaly variables

But there is more to chat about :-). Let me know if it would help to make this changes with the MOHC branch, or you could try merging that with the latest master.

[Kate-Willett]

I will try adding climatology info to long_name.

[gleckler1]

@Kate-Willett That is a good path!