Annual mean temperature unit

[michael-matejka]

@barlage I am wandering what is the right unit (°C/K) for annual mean temperature for initializing HRLDAS.

In this, otherwise very useful, NCL script is is defined in °C ("annual_mean_temperature = 10.9 ; will be used as deep soil temperature"), but the variable TMN where it is stored is generally considered to be in K (in the HRLDAS code)

https://github.com/NCAR/hrldas-release/blob/c4e69907d684338c81dc8a1804ab39d9c47d4774/HRLDAS/HRLDAS_forcing/run/examples/single_point/create_setup.ncl

Thank you for help.