H2O feedback

  • H2O feeback is a new feedback since the last hybrid model at UM10.4.
  • Θv and m_* fields are altered by an update to q
  • Currently it comes after call to UKCA_MAIN1, but before the coupling exchange. Hence, I've had to move it. The choice being
    • Move coupling exchange earlier
    • Move the H2O feedback calculation after coupling exchange. This is the easier option which I've currently gone with, see UM #3875.
  • Applying this in hybrid means that coupling Θv from Snr -> Jnr is replaced by coupling q from Jnr -> Snr.
  • This is counter to the locking direction we want.
  • Colin has suggested we should be passing the increment on q, which hasn't been done yet.