Peter Rayer

Areas of expertise

  • clear-air radiative transfer
  • the fast model RTTOV

Current activities

Peter works on the development of both line-by-line and 'fast' RT models. Line-by-line models calculate detailed line spectra at the molecular level, whereas fast models are parametrised by channel-averaged line spectra to process satellite data for operational applications. For the Met Office and many other users world wide, the fast model RTTOV plays an important role in assimilating satellite observations for NWP. Peter's research aims to develop the capabilities of RTTOV in a collaborative project with Météo-France and ECMWF as part of the NWP SAF, which is funded by EUMETSAT.

One goal is to increase the flexibility of RTTOV for the user, and Peter has recently installed an in-stream interpolator and an improved representation of the profile top. Another goal is to increase the scientific scope of the model, and his current work aims to include the Zeeman effect in RTTOV as a routine option. This will allow better use of high-sounding satellite instruments that probe the mesosphere. 

Career background

Having spent some years in professional work unrelated to science, Peter changed direction, graduated in physics, and joined the Met Office for the opportunity to sample a wide range of research fields.

He began as a key developer of the original Open Road ice prediction scheme, and then undertook a spell of bench forecasting for aviation, including time at London Heathrow Airport.

He first became involved with the modelling of atmospheric radiative transfer as part of a Met Office collaboration with atmospheric physicists at Oxford University. After working with the Remote Sensing Instrumentation branch, then located at RAE Farnborough, he returned to the main site at Exeter and is now more concerned with model development.

Peter has, for some time, taken a special interest in the molecular processes underlying the modelling work, and particularly in the pressure-broadening of spectral lines. This keeps him in touch with the fundamentals, and with external theoretical work on important problems of the day, which include line interference, the line far-wing, and the water vapour continuum.