11.3 Input Standards
11.3.1 Meteorology Standards
11.3.1.1 Dimensions:
| CF standard-name | units |
|---|---|
| time | days since 1700-01-01 00:00:00 UTC |
| longitude | degrees_east |
| latitude | degrees_north |
General Note: dates in the database should be date-time (preferably with timezone), and datetime passed around in PEcAn should be of type POSIXct.
11.3.1.2 Variable names should be standard_name
- preferred variables indicated in bold
- wind_direction has no CF equivalent and should not be converted, instead the met2CF functions should convert wind_direction and wind_speed to eastward_wind and northward_wind
- standard_name is CF-convention standard names
- units can be converted by udunits, so these can vary (e.g. the time denominator may change with time frequency of inputs)
- soil moisture for the full column, rather than a layer, is soil_moisture_content
- The list of PEcAn standard variable names, units and dimensions are provided in a table in the Output Standards section and maintained in the file: base/utils/data/standard_vars.csv.
For example, in the MsTMIP-CRUNCEP data, the variable rain should be precipitation_rate.
We want to standardize the units as well as part of the met2CF.<product> step. I believe we want to use the CF “canonical” units but retain the MsTMIP units any time CF is ambiguous about the units.
The key is to process each type of met data (site, reanalysis, forecast, climate scenario, etc) to the exact same standard. This way every operation after that (extract, gap fill, downscale, convert to a model, etc) will always have the exact same inputs. This will make everything else much simpler to code and allow us to avoid a lot of unnecessary data checking, tests, etc being repeated in every downstream function.
11.3.2 Soils and Vegetation Inputs
11.3.2.1 Soil Data
See the Soil Data section on more into on creating a standard soil data file.
11.3.2.2 Vegetation Data
See the Vegetation Data section on more info on creating a standard vegetation data file