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. Motivation Durkee et al. 2000 0.63 micron3.7 micron

5. 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

6. 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

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

8. 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

9. Platforms 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 Satellite Observations

10. Aerosol Instruments 1.2 Grab bags fitted with Teflon filter 2.Desert Research Institute’s CCN counter 3.Counter-flow Virtual Impacter 4.Passive Cavity Aerosol Spectrometer Probe 5.TSI 3010 Condensation Nuclei (CN) counter 6.Radially Classified Aerosol Detector (RCAD) 7.Active Scattering Aerosol Spectrometer Probe (ASASP-X)

11. 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

12. Decrease in R e R e(ship track) - R e(ambient) (µm)

13. Increase in CCN concentration % increase in drop concentration

14. Cloud Microphysical Response

15. “All Aerosols are not activated as CCN”

16. CCN Activation Several Distances away from Hanjin Barcelona

18. 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.

19. Plume Formation

20. Diesel Vs Steam/Gas turbine Diesel Engine powered Steam/Gas Turbine powered Marine Fuel oilNavy Distillate Fuel Higher N CCN /N total ratio Lower N CCN /N total ratio Particle range 0.01 – 0.1 µm Particle range <0.03 µm

21. Background Cloud Conditions

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

23. 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