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M onterey A rea S hip T rack (MAST) Experiment

M onterey A rea S hip T rack (MAST) Experiment. Virendra P. Ghate MPO 531. Outline. Motivation Objectives of MAST Instrumentation Procedure Observations/Results Conclusions. Motivation. MODIS 27 Jan 2006. Why study them?. Twomey Effect:

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M onterey A rea S hip T rack (MAST) Experiment

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  1. Monterey Area Ship Track (MAST) Experiment Virendra P. Ghate MPO 531

  2. Outline • Motivation • Objectives of MAST • Instrumentation • Procedure • Observations/Results • Conclusions

  3. Motivation MODIS 27 Jan 2006

  4. Why study them? • Twomey Effect: " cloud reflectivity is enhanced due to increased concentrations of cloud droplets associated with the increased condensation nuclei associated with polluted air " Twomey 1977

  5. Why study them? • Albrecht Effect " Increase in the CCN leads to smaller effective cloud drop radius leading to inhibition of drizzle and further increase in cloud cover " Albrecht 1989

  6. MAST Objectives • Aerosol-Cloud Interactions and cloud microphysics. • Boundary Layer perturbations by ship. • Cloud Dynamics. • Background Environmental conditions. Durkee et al. 2000

  7. Cloud Microphysics Objectives • Aerosols from ship’s stack are responsible for ship track formation. • Aerosols from ship’s water wake are responsible for ship track formation. • Aerosol injection in precipitating clouds tends to inhibit precipitation. • Etc. Durkee et al. 2000

  8. Aircrafts UW’s C131 UK Met. Office C130 NRL Airship Ships R/V Glorita Steam turbine ships Gas turbine ships Diesel engine ships Nuclear powered ships Platforms Satellite Observations

  9. Aerosol Instruments • 2 Grab bags fitted with Teflon filter • Desert Research Institute’s CCN counter • Counter-flow Virtual Impacter • Passive Cavity Aerosol Spectrometer Probe • TSI 3010 Condensation Nuclei (CN) counter • Radially Classified Aerosol Detector (RCAD) • Active Scattering Aerosol Spectrometer Probe (ASASP-X)

  10. Taxi to MAST research area Locate ship using radar Get plume location Ship speed, wind velocity Sample BL at different heights with plume perpendicular transects Try locating plume cloud entrance location

  11. Decrease in Re Re(ship track) - Re(ambient) (µm)

  12. Increase in CCN concentration % increase in drop concentration

  13. Cloud Microphysical Response

  14. Cloud Microphysical Response “All Aerosols are not activated as CCN”

  15. CCN Activation Several Distances away from Hanjin Barcelona

  16. Chemical Signature • Increase of 3-4 µg m-3 in sulphate concentration above the ambient values. • NYK Sunrise plume contained higher silicon component. • Links strong evidence to plume formation from stack emissions.

  17. Diesel Vs Steam/Gas turbine

  18. Background Cloud Conditions

  19. Wake Particles • Very few particles >0.2 µm • Particles not lofted to cloud fast enough

  20. Conclusions • Particles from ship stack responsible for ship track formation. • Diesel powered ships produce stronger and more ship tracks. • Ship tracks are more prolific in less polluted ambient air. • Deeper BL depth (>800 m) inhibits ship track formation. • No ships produced recognizable signature in water wake in size distribution or chemically

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