VOCALS

1. VOCALS

2. VOCALS THEME To better understand and simulate how marine boundary layer cloud systems surrounding the Americas interact with the coupled ocean-atmosphere-land system on diurnal to interannual timescales.

3. VOCALS in CLIVAR • VOCALS is a developing process study within VAMOS, informally led by C. Bretherton. • WG meetings at VPM3-6. • Active participants: US (Albrecht, Bretherton, Fairall, Mechoso, Miller, Stevens, Weller) Chile (Garreaud, Ruttland) Uruguay (Terra) Peru (Lagos) Ecuador (Cornejo) • Science Plan on my web page.

4. VOCALSScientific Issues • Time and space scales of CTBL-continent interaction. • Regional S/I feedbacks between Sc clouds, surface winds, upwelling, coastal currentsand SST in E Pacific. • Feedbacks of Eastern Pacific cloud topped boundary layer properties on overall tropical circulation and ENSO. • Climatic importance of aerosol-cloud interactions.

5. VOCALS STRATEGIES • Global and mesoscale model evaluation and improvement (e.g parameterization development) using multiscale data sets. • Model sensitivity studies to refine hypotheses and target observations. • Science by synthesis/use of existing data sets, enhancement through targeted instrument procurement, algorithm evaluation and development, and enhanced observation periods. • Co-ordination with oceanographic, aerosol, cloud process communities, including CLIVAR CPTs, CLOUDSAT, etc.

7. DYCOMS-II RICO Galapagos I. TAO-EPIC Lima Arica EPIC2001-Sc WHOI buoy San Felix I. Scientific Highlights from EPIC & DYCOMS

8. TAO-EPIC has gathered a nice multiyear dataset Yearly Feb-Apr precip in SE Pacific ‘ITCZ’ …and freshening Cronin

9. 2.5 years of data from the WHOI stratus buoy (20S 85W) Weller

10. Buoy shows large net heat flux into ocean balancing eddy cooling Weller

11. Ocean altimetry shows energetic eddy field Weller

12. GOES-10 Visible Image October 17 1500 UTC Peru 10°S x 20°S x 90°W 80°W 70°W EPIC 2001Sc cruise

13. 19 20 21 22 00 06 Latitude (ºS) 60 km GOES VIS 0545 LT C-band 0200 LT 87 86 85 84 83 60 km Longitude (ºW) 1.5 1.0 0.5 Height (km) MMCR 00 02 04 06 October 19 (Local Time) Inhomogeneous clouds

14. [cm s-1] ECMWF VERTICAL VELOCITY Daytime subsidence max EPIC2001-Sc Diurnal Cycle (20S, 85 W) 10 [dBZ] 0 -10 Bretherton et al. (2004)

15. Diurnal variation of horizontal surface wind divergence (Quikscat) Wood seabreeze ? PM subsidence max AM subsidence max Hypothesis: Subsidence wave driven by diurnal heating cycle over Andes reaches buoy at noon.

16. MM5 simulation also shows late afternoon convergence at coast, midnight ascent at buoy! 06LT 18LT Garreaud et al. (2004)

17. Remotely-sensed cloud microphysics from EPIC2001-Sc Bretherton et al. (2004) Significant drizzle in clean periods, but mainly evaporates

18. MODIS visible reflectance, 15Z 20 Oct. 2001 POC (patch of cells)

19. MODIS effective cloud droplet radius – large (clean) in POC small in coastal pollution

20. DYCOMS-II RF02 POC – drizzle feedback? Stevens

21. DYCOMS-II Sc entrainment estimates from RF01 Stevens

22. Comparison of 6-day mean 20S 85W profiles with models (Peter Caldwell, UW) • All models have adequate Sc, but too shallow a PBL. • CAM2 LWC all in lowest 3 levels (70-630 m). • Observed LWC mainly at 800-1300 m.

23. U. Chile has installed ceilometer and surface met at San Felix Is. Decoupled Cloud base (ceilometer) LCL (surface met) Well-mixed Mostly clear Garreaud Shows daytime rise of LCL, cld. base, with synoptic variations

24. Other active issues • Role of Andes and Amazonia (flow blocking, deep convection) in influencing Sc. • Comparison of WHOI buoy and TAO-EPIC ocean energy budgets with GCMs. • Interest in coastal oceanography of region, including O-A interactions thru trapped coastal (e.g. Kelvin) waves. • ENSO feedbacks with SE and NE Pacific clouds • Shallow cumulus dynamics/microphysics – Sc to Cu transition (McCaa and Bretherton 2004; Wang et al. 2004)

25. VOCALS Thrusts • Continuing diagnostic, model sensitivity, parameterization studies of SE/NE Pac stratocumulus and variability based on past field studies, satellite/model products, and in-situ observational enhancements. • Contribution to RICO (Jan 2005, shallow Cu) • Add ocean diagnostic study component based on ARGO/ODA, cruises, WHOI buoy aimed at better understanding of ocean upwelling/lateral heat transport processes and their reln. to atmospheric variability. • Global atm./coupled, mesoscale atm., and regional ocean modeling. • ‘Radiator fin’ coupled O-A-L expt. (Oct 2006)

26. VOCALS short-term implementation • Augment San Felix Island instrumentation with wind profiler, radiation, microwave LWP, and aerosol sampler. • NOAA/ETL sfc/remote sensing instrumentation on Pacific and Atlantic buoy maintenance cruises, and at RICO (funded). • Develop VOCALS data set through distributed satellite/model/in situ data archive at JOSS. Archive ECMWF and NCEP hi-res column data at WHOI buoy, SFI in co-ordination with CEOP (some funding). • Work with cloud-climate sensitivity CPT to feed into coupled model development.

27. VEPIC Timeline • 2003-2010 • diagnostic/modeling work 2003 ETL-enhanced cruises • SFI profiler • VEPIC data archive • 2004/11 Cloudsat • 2005/01 RICO • 2006/10 Radiator expt. Modeling, empirical, and satellite studies

28. RICO (Rain In Cumulus over the Oceans)

32. Requested (Fairall) Pan Am Panel Endorsement?

35. Diurnal subsidence wave Cld microphys. gradient Coastal jet Ocn heat transport

36. What VOCALS would like from you • A letter from the panel to Mike Patterson endorsing the use of the Ron Brown in RICO to provide critical time-continuous open-ocean radar, radiometric, turbulence, and other in-situ measurements that will greatly enhance RICO’s potential to contribute to shallow cumulus and cloud microphysical parameterizations in climate models. • Panel approval of VOCALS as a US CLIVAR sanctioned activity as part of PACS funding AOs. • Also, panel must consider equatorial EPIC’s heritage.