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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. PACS STRATUS 2003. left Manta Ecuador, went to 85W line, traveled south to 20S stayed at WHOI buoy from Nov. 15 – 21 (12 UTC)
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Preliminary Results from Stratus 03 Cruise on R/V RevelleFairall, Zuidema, Hare, Kollias, TomlinsonWCRP/CLIVAR/VAMOS Panel Meeting 7Guayaquil, EcuadorMarch 2004
PACS STRATUS 2003 • 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
Observation Systems Cloud Radar and Microwave Radiometer Climate Reference Buoy
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
BL winds from SE, above-BL-winds more variable (synoptics?) Both virtual potential temperature and LCL show influence of drizzle
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
Clouds at buoy thin compared to the rest of the cruise (and to EPIC 2001)
Chris Fairall’s simple aerosol counter compares well to Don Collins’ aerosol measurements (r>0.1 micron)
Aerosol indirect effectWithin well-mixed non-precipitating clouds, expect -dlnr/dlnN = 0.3 sometimes it’s there, sometimes not
What is the relationship between drizzle, aerosol, and liquid water path ?