Browsing by Author "Nott, G. J."

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Characterizing instrumentation canister aerodynamics on the FAAM BAe-146-301 atmospheric research aircraft
    (ASCE, 2019-04-30) Bennett, Christopher J.; Wellpott, A.; Lawson, Nicholas J.; Delise, M.; Woodcock, B.; Gratton, Guy; Nott, G. J.
    A computational fluid dynamics (CFD) investigation was aimed at accurately predicting the air flow characteristics in the vicinity of underwing-mounted instruments on the Facility for Airborne Atmospheric Measurement’s (FAAM) BAe-146-301. Perturbation of the free stream airflow as it passes through the region of detection of the underwing instruments may lead to additional uncertainties in the measurement of clouds and cloud particles. The CFD model was validated with flight data from an Aircraft-Integrated Meteorological Measurement System (AIMMS-20) in a wing-mounted instrument canister. Flow predictions showed a consistent slowing from the true air speed of the aircraft in the longitudinal direction and the introduction of horizontal and vertical flows up to 10% of the air speed. The potential impact of these flow perturbations on sizing of particles with cloud imaging probes was modeled. Sizing errors were dependent on the methodology used and the shape of the particle; those due to transverse flows remained very small but mis-sizing due to unaccounted longitudinal flow perturbations were potentially more serious.
  • Thumbnail Image
    ItemOpen Access
    Coordinated Airborne Studies in the Tropics (CAST)
    (American Meteorological Society, 2017-01-23) Harris, Neil; Bauguitte, Stéphane J.-B.; Nott, G. J.; Wellpott, A.
    The main field activities of the Coordinated Airborne Studies in the Tropics (CAST) campaign took place in the west Pacific during January–February 2014. The field campaign was based in Guam (13.5°N, 144.8°E), using the U.K. Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 atmospheric research aircraft, and was coordinated with the Airborne Tropical Tropopause Experiment (ATTREX) project with an unmanned Global Hawk and the Convective Transport of Active Species in the Tropics (CONTRAST) campaign with a Gulfstream V aircraft. Together, the three aircraft were able to make detailed measurements of atmospheric structure and composition from the ocean surface to 20 km. These measurements are providing new information about the processes influencing halogen and ozone levels in the tropical west Pacific, as well as the importance of trace-gas transport in convection for the upper troposphere and stratosphere. The FAAM aircraft made a total of 25 flights in the region between 1°S and 14°N and 130° and 155°E. It was used to sample at altitudes below 8 km, with much of the time spent in the marine boundary layer. It measured a range of chemical species and sampled extensively within the region of main inflow into the strong west Pacific convection. The CAST team also made ground-based measurements of a number of species (including daily ozonesondes) at the Atmospheric Radiation Measurement Program site on Manus Island, Papua New Guinea (2.1°S, 147.4°E). This article presents an overview of the CAST project, focusing on the design and operation of the west Pacific experiment. It additionally discusses some new developments in CAST, including flights of new instruments on board the Global Hawk in February–March 2015.