An external view of the Met Office building at night.

Dr R. Chawn Harlow

Chawn manages the Satellite Radiance Assimilation Group which is responsible for processing the satellite radiance data which is assimilated into the Met Office NWP System.

Areas of expertise

  • Airborne retrievals of millimetre wave surface emissivities and effective temperature.
  • Microwave emission modelling particularly of snow packs.
  • Lambertian and specular surface interaction.
  • Clear air microwave radiative transfer.

Publications by Chawn

Current activities

Chawn manages the R&D program and associated staff that aim to improve the assimilation of microwave and infrared satellite radiances into the Met Office operational Numerical Weather Prediction (NWP) modelling system.

He collaborates with the satellite sounding and NWP communities to improve the use of such satellite data within NWP and in other Earth science applications.

Chawn also liaises with industry and the space agencies, UKSA, ESA and EUMETSAT, to promote the development of future satellite instruments valuable to the NWP community.

Career background

Chawn graduated from high school in Lakeview, Oregon, in June 1987. He received the B.Sc. degree in physics and astronomy; the M.Sc. degree in physics; and the Ph.D. degree in hydrology, with a minor in atmospheric science, from the University of Arizona, Tucson, in 1992, 1994, and 2003, respectively, where his dissertation was titled "Remote and in situ measurement of soil moisture and vegetation water content."

From 2005 to 2010, he served as Radiation Research Scientist with the Observational Based Research at the Met Office based in Exeter. His work focused on snow and sea-ice emissivities in the Advanced Microwave Sounding Unit and Microwave Humidity Sounder wavelengths in order to improve satellite retrievals of atmospheric profiles of temperature and humidity. He also served as a Mission Scientist and MARSS Operator on the FAAM BAe-146 atmospheric research aircraft.

From the beginning of 2011 to end of 2017, Chawn served as Manager of the Atmospheric Radiation Group and Chairman of the FAAM Radiation and Lidar Instrument Working Group. While managing the Atmospheric Radiation Group, Chawn led airborne campaigns related to remote sensing of the atmosphere and surface using the FAAM aircraft. These included the Met Office contribution to CLPX-II (2008), the MEVALI (2012), SALSTICE (2013), COSMICS/CIRCCREX (2015), and MACCSIMIZE (2018).

From September 2017 to present, Chawn has managed the Satellite Radiance Assimilation Group.

External recognition

In February 2010, Chawn received the L. G. Groves Memorial Prize for Meteorological Observations for his contribution to the planning and implementation of the CLPX-II campaign.