Paul Barrett analyses cloud physics observations from research aircraft, using them to study microphysical processes in the Unified Model
Areas of expertise:
Research aircraft observations;
Counterflow Virtual Impactor (CVI);
Marine Boundary Layer studies;
Comparison of Unified Model output with observations.
Paul works closely with the FAAM BAe146 Atmospheric Research Aircraft. He flies onboard the aircraft during data collection missions, and uses data collected by this aircraft to study the physical processes that affect clouds, in an effort to better represent these in the Unified Model.
With this data he is currently investigating the marine boundary layer of the South Eastern Pacific, following VOCALS-REx, an international study that took place during October 2008. In addition to the FAAM data he has taken advantage of access to data products from the NCAR C130, the Ron H. Brown research vessel, and coastal ground based observations. Investigation into the diurnal cycle of turbulence and thermodynamic stability in the boundary layer of this region will allow him to make an assessment of the performance of the Unified Model. Study of this region is important as the extensive low lying Stratocumulus clouds have a large impact on the radiative balance of the Earth.
Paul is also responsible for the development of the Counterflow Virtual Impactor (CVI) probe, used to investigate properties of clouds. This probe evaporates the water from cloud droplets to leave water vapour and a residual cloud condensation nucleus (CCN) aerosol particle. These residuals are analysed downstream, where size, and chemical composition are analysed. One of the current research areas involves developing the instrument to enable the accurate assessment of the chemical species that make up CCN.
Paul joined the Met Office and the Cloud Physics group in summer 2007. His time in the office has been spent understanding the data from the FAAM BAe146, and the workings of the Unified Model. He has attempted to forge links with outside users of the this aircraft and the data, in order to develop the research capability of the Met Office as a whole.
Paul studied Physics as an undergraduate at the University of Sheffield, where he gained an Mphys (Hons), following completion of a four year degree and research project. The project involved detecting oxidising gases by measuring a change in the optical properties of a Langmuir-Blodgett thin film of aromatic compounds. Upon adsorption of a gas the optical transmission of the film dropped significantly. The work was aimed at improving the response time of the sensor, in order to provide timely notification of potentially dangerous elevated gas concentrations.
Following this he spent time working in the asbestos remediation industry. This saw him travel the country with a mobile laboratory to test for the presence and concentration of airborne asbestos fibres, to ensure public and worker safety.