Page 1© Crown copyright The Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 Steve Abel First VOCALS Regional Experiment (REx) Preparatory Workshop June

Page 2© Crown copyright Outline  Brief overview of the BAe-146 aircraft  Participation in VOCALS (Aims, flight hours etc)  Instrumentation and capabilities  Aircraft endurance in VOCALS

Page 3© Crown copyright The FAAM BAe-146 aircraft

Page 4© Crown copyright The FAAM BAe-146 aircraft

Page 5© Crown copyright Inside the Aircraft Maximum of 18 scientists

Page 6© Crown copyright Aims Focus on the relationship between microphysics and the cloud macrostructure, exploring in particular some of the following issues: The physical and chemical properties of aerosol within and above the boundary layer and its relationship to natural or anthropogenic sources. Include the characterisation of distinct aerosol plumes from anthropogenic sources The extent to which drizzle formation within the cloud layer can be related to aerosol characteristics (mass loading, number concentration and speciation) The role of drizzle in generating large variations in the liquid water path The relative role of anthropogenic aerosol in determining the droplet effective radius and SW cloud radiative forcing of cloud in the region. In addition to these primary interests, we will also be seeking to obtain measurements that help to validate other aspects of physical parametrizations relevant to the stratocumulus-topped boundary layer: Cloud-top entrainment and its relationship to the radiative flux divergence Measurements of TKE within the boundary layer to inform the extent to which it is damped by drizzle.

Page 7© Crown copyright BAe-146 participation in VOCALS Currently scheduled to arrive in Chile on 8 th Nov 2008 and depart on 26 th Nov 2008 Looking at possibility of bringing this forward (up to 3 weeks) for more overlap with the C-130 Total of 120 flight hours including transit 15 potential flight days 10 flights ~ hrs duration Day and night flights possible Min altitude: 50 ftMaximum altitude: 35,000 ft The BAe-146 measurements will provide important additional information of cloud microphysics, aerosols, and cloud radiative properties

Page 8© Crown copyright Instrumentation During VOCALS the BAe-146 will be in it’s radiation and cloud/aerosol physics mode. In addition to this instrumentation (see next slides) the aircraft will be fitted with Core chemistry: CO, O 3, NO x Thermodynamics: Temperature, Humidity, Pressure…… Dynamics: Turbulence probe Sondes Video Cameras: Upward, Downward, Forward, Rear

Page 9© Crown copyright Aerosol and Cloud Measurements: Size Spectra PCASP FFSSP CDP SID-2 2D-C 2D-P CIP-25 CIP-100 2D-S CAPS (CAS + CIP) SMPS UHSAS CoreNon-core

Page 10© Crown copyright Aerosol and Cloud Measurements: Bulk LWC: Johnson Williams, Nevzerov LWC, Nevzerov TWC Total Water Content: Liquid + Ice + Vapour (Lynman-α absorption hygrometer) CCN: Dual channel continuous flow Condensation Particle Counter: TSI-3025A Aerosol concentration > 3 nm Aerosol Mass Spectrometer: Mass of non-refractory components of aerosol particles as a function of size (50 – 500 nm) Single Particle Soot Photometer (SP2): Black carbon mass (single particle basis) Filters: Sub and Supermicron CVI: Counter Flow Virtual Impactor (Residual particle & vapour from cloud drops) Nephelometer: Aerosol scattering (dry) at λ = 450,550,700 nm Wet Nephelometer: Aerosol scattering f(RH) at λ = 450,550,700 nm PSAP: Aerosol absorption at λ = 567 nm

Page 11© Crown copyright Radiation Instrumentation Microwave Radiometer (MARSS): Upward and downward pointing (+40 to -40 deg) 5 channels GHz Derive LWP, T + q structure Shortwave Spectrometer (SWS): Pointable high resolution spectrometer measuring radiance across spectral range 0.3 – 1.7 μm MODIS type retrievals of cloud properties Spectral Hemispheric Irradiance Measurement (SHIM): As SWS but hemispherically integrating. Mounted on top and bottom of aircraft. Derive cloud optical depth Broad Band Radiometers: Derive cloud optical depth Heiman Radiometer: Sea surface temperature Airborne Research Interferometer Evaluation System (ARIES): Interferometer producing high resolution spectra 18 – 3.3 μm. Retrieve profiles of gases (CO 2, H 2 O, O 3 etc) and sea surface temperature. Cloud info incl cloud top temp…… LIDAR: O 3, H 2 O, aerosol profiles. Unlikely due to weight impact on endurance.

Page 12© Crown copyright Aircraft Endurance Based at Iquique: 5 hrs Based at Arica: 5 hrs 25 mins Dependent on scientific payload Difference is due to diversion airports

Page 13© Crown copyright Aircraft Endurance ~ 1–1.5 hr dependant on FL Transit to 75 o W at medium level and have approximately 3 hours on task in the region MODIS image courtesy of MODIS Rapid Response Project at NASA/GSFC

Page 14© Crown copyright Aircraft Range: Maximum in BL ~ 78 o W

Page 15© Crown copyright Aircraft Range: Maximum at mid-level (FL100) ~ o W

Page 16© Crown copyright Questions