1. Preliminary Results from Stratus 03 Cruise on R/V Revelle Fairall, Zuidema, Hare, Kollias, Tomlinson WCRP/CLIVAR/VAMOS Panel Meeting 7 Guayaquil, Ecuador March 2004

2. PACS STRATUS 2003 Differences from the (October) EPIC 2001 cruise:
left Manta Ecuador, went to 85W line, traveled south to 20S
stayed at WHOI buoy from Nov. 15 – 21 (12 UTC)
traveled east along 20S to Arica Chile
data taken Nov. 13 – Nov. 24
Aerosol measurements taken (new) but no C-band radar
Differences from the (October) EPIC 2001 cruise:
fewer & thinner clouds & less drizzle,
particularly at the buoy (now at stratus deck edge)
diurnal cycle in large-scale subsidence in
inversion/cloud-top height weaker?
SSTs ~ 1K warmer; cloudbase higher

5. Observation Systems Cloud Radar and Microwave Radiometer
Climate Reference Buoy

6. Above-BL moisture appears to subside into the BL, separated by ~ 4 days, coinciding with a rising cloud top and drizzle at surface (JD 324).
Pink indicates radar-derived cloud top

7. BL winds from SE, above-BL-winds more variable (synoptics?)
Both virtual potential temperature and LCL show influence of drizzle

8. 85W, 20S: Inversion less developed in Nov. 2003 than Oct. 2001
Boundary layer warmer ~ 1.5K, higher moisture content, less RH RH T T q q q v e
PACS03 q
EPIC01

9. Clouds at buoy thin compared to the rest of the
cruise (and to EPIC 2001)

10. Chris Fairall’s simple aerosol counter compares well to Don Collins’ aerosol measurements (r>0.1 micron)

11. Aerosol indirect effect Within well-mixed non-precipitating clouds, expect -dlnr/dlnN = 0.3 sometimes it’s there, sometimes not

12. What is the relationship between drizzle, aerosol, and liquid water path ?

13. As well as surface fluxes….

14. Comparison of Cloud Diurnal Cycle: Epic2001 vs Stratus2003