VOCALS-REx airborne observations of the physical characteristics of the SE Pacific cloud-topped boundary layer along 20S Chris Bretherton, Rob Wood, Rhea.

Slides:



Advertisements
Similar presentations
Impacts of Large-scale Controls and Internal Processes on Low Clouds
Advertisements

The Pre-VOCALS Model Assessment (PreVOCA) Matt Wyant Chris Bretherton Rob Wood, Univ. of Washington Roberto Mechoso, UCLA...and most important... Participating.
EPIC 2001 SE Pacific Stratocumulus Cruise 9-24 October 2001 Chris Bretherton and Sandra Yuter (U. Wash.) Chris Fairall, Taneil Uttal (NOAA/ETL) Bob Weller.
The Pre-VOCA Model Assessment Matt Wyant Roberto Mechoso Rob Wood Chris Bretherton with help from participating modeling groups, Dave Leon (U Wyo), Rhea.
Robert Wood, University of Washington many contributors VOCALS Regional Experiment (REx) Goals and Hypotheses.
Towards stability metrics for cloud cover variation under climate change Rob Wood, Chris Bretherton, Matt Wyant, Peter Blossey University of Washington.
Robert Wood Atmospheric Sciences, University of Washington Image: Saide, Carmichael, Spak, Janechek, Thornburg (University of Iowa) Image: Saide, Carmichael,
Warm rain variability and its association with cloud mesoscale structure and cloudiness transitions Robert Wood, University of Washington with help and.
Precipitation and albedo variability in marine low clouds
The VOCALS Assessment (VOCA) Matt Wyant, Chris Bretherton, Rob Wood Department of Atmospheric Sciences University of Washington Scott Spak, U. Iowa (Emissions)
VOCALS Chris Bretherton, Univ. of Washington. VOCALS THEME To better understand and simulate how marine boundary layer cloud systems surrounding the Americas.
EPIC 2001 SE Pacific Stratocumulus Cruise 9-24 October 2001 Rob Wood, Chris Bretherton and Sandra Yuter (University of Washington) Chris Fairall, Taneil.
Condensation in the Atmosphere The atmosphere contains a mixture of dry air and a variable amount of water vapor (0-4% or 0-30 g/kg) An air parcel is said.
Introduction to Cloud Dynamics We are now going to concentrate on clouds that form as a result of air flows that are tied to the clouds themselves, i.e.
Synthesis NOAA Webinar Chris Fairall Yuqing Wang Simon de Szoeke X.P. Xie "Evaluation and Improvement of Climate GCM Air-Sea Interaction Physics: An EPIC/VOCALS.
Lecture 15, Slide 1 Physical processes affecting stratocumulus Siems et al
RICO Modeling Studies Group interests RICO data in support of studies.
Robert Wood, Atmospheric Sciences, University of Washington The importance of precipitation in marine boundary layer cloud.
Coupled vs. Decoupled Boundary Layers in VOCALS-REx Chris Jones and Chris Bretherton Department of Atmospheric Sciences University of Washington Dave Leon.
VOCALS-REX CTBL and Aerosols Rob Wood and Chris Bretherton, Univ. of Washington Chris Fairall, NOAA-ETL.
Using WRF-Chem to understand interactions between synoptic and microphysical variability during VOCALS Rhea George, Robert Wood University of Washington.
A Case Study of Decoupling in Stratocumulus Xue Zheng MPO, RSMAS 03/26/2008.
The EPIC 2001 SE Pacific Stratocumulus Cruise: Implications for Cloudsat as a stratocumulus drizzle meter Rob Wood, Chris Bretherton and Sandra Yuter (University.
Mesoscale variability and drizzle in stratocumulus Kim Comstock General Exam 13 June 2003.
A synthesis of published VOCALS studies on marine boundary layer and cloud structure along 20S Chris Bretherton Department of Atmospheric Sciences University.
Many models show a substantial drop off in droplet number away from the coast as is observed. Models’ vertical distribution of droplet number is surprisingly.
VOCALS-REx Flight Planning. VOCALS Regional Experiment (REx) VOCALS-Rex will collect datasets required to address a set of issues that are organized into.
Condensation in the Atmosphere
Matthew Christensen and Graeme Stephens
SE Pacific Sc Research at UW
Stratocumulus cloud thickening beneath layers of absorbing smoke aerosol – Wilcox, 2010 The semi-direct aerosol effect: Impact of absorbing aerosols.
Condensation in the Atmosphere
Seamless turbulence parametrization across model resolutions
Robert Wood, University of Washington
Preliminary Results from Stratus 03 Cruise on R/V Revelle Fairall, Zuidema, Hare, Kollias, Tomlinson WCRP/CLIVAR/VAMOS Panel Meeting 7 Guayaquil, Ecuador.
VOCALS-REx airborne observations of the physical characteristics of the SE Pacific cloud-topped boundary layer along 20S Chris Bretherton, Rob Wood, Rhea.
Understanding warm rain formation using CloudSat and the A-Train
Condensation in the Atmosphere
A Comparison of Regional and Global Models during VOCALS
Tropical Jets and Disturbances
Control of Cloud Droplet Concentration in Marine Stratocumulus Clouds
VEPIC Update Goals and methods Targeted extended time observations
Roberto Mechoso and I. Richter
Cloudsat and Drizzle: What can we learn
Group interests RICO data required
Rob Wood, University of Washington POST Meeting, February, 2009
Simple CCN budget in the MBL
Robert Wood University of Washington
VOCALS Chris Bretherton, Univ. of Washington
SAR remote sensing of open mesoscale cellular convection
Large-Eddy Simulation of the VOCALS RF06 Pocket of Open Cells:
The Pre-VOCA Model Assessment
Control of Cloud Droplet Concentration in Marine Stratocumulus Clouds
EPIC 2001 SE Pacific Stratocumulus Cruise 9-24 October 2001 Rob Wood, Chris Bretherton and Sandra Yuter (University of Washington) Chris Fairall, Taneil.
The importance of precipitation in marine boundary layer cloud
NRL POST Stratocumulus Cloud Modeling Efforts
Short Term forecasts along the GCSS Pacific Cross-section: Evaluating new Parameterizations in the Community Atmospheric Model Cécile Hannay, Dave Williamson,
EPIC 2001 SE Pacific Stratocumulus Cruise 9-24 October 2001 Rob Wood, Chris Bretherton and Sandra Yuter (University of Washington) Chris Fairall, Taneil.
VOCALS Open Ocean: Science and Logistics
Cloudsat and Drizzle: What can we learn
Total surface flux (+up) from models
Cloudsat and Drizzle: What can we learn
Rob Wood, University of Washington POST Meeting, February, 2009
The Pre-VOCALS Model Assessment (PreVOCA)
VEPIC Update Goals and methods Targeted extended time observations
VOCALS-REx airborne observations of the physical characteristics of the SE Pacific cloud-topped boundary layer along 20S Chris Bretherton, Rob Wood, Rhea.
EPIC 2001 SE Pacific Stratocumulus Cruise 9-24 October 2001 Rob Wood, Chris Bretherton and Sandra Yuter (University of Washington) Chris Fairall, Taneil.
Rob Wood, Chris Bretherton, Matt Wyant, Peter Blossey
The EPIC 2001 SE Pacific Stratocumulus Cruise: Implications for Cloudsat as a stratocumulus drizzle meter Rob Wood, Chris Bretherton and Sandra Yuter.
Group interests RICO data in support of studies
Presentation transcript:

VOCALS-REx airborne observations of the physical characteristics of the SE Pacific cloud-topped boundary layer along 20S Chris Bretherton, Rob Wood, Rhea George (U. Washington) Dave Leon (U. Wyoming) Grant Allen (U. Manchester) and the VOCALS Team VOCALS RF05, 72W 20S

Goal and approach Document the structure of the cloud-topped boundary layer along 20S across persistent gradients in aerosols and cloud morphology during VOCALS REx. Focus on observations relevant for large-scale modeling. Use multiplatform observations (C130, BAe146, Twin Otter aircraft, Ron Brown ship, Iquique soundings) during 16 Oct.-15 Nov 2008 in 19-21S.

20S IR strip charts (0845 UTC) 20S airborne obs cover a representative range of cloud conditions B412 B410 RF07 RF14 B420 RF13 RF05 RF04 B417 RF03 RF10 RF02 B414 RF09

Monthly-mean T, q profiles Weighted average of C130, 146 dropsonde, Brown, Iquique 10K inversion: sharp, ~ 1000 m at coast ~ 1600 m at 85W Free trop warmer near S Amer coast PBL well-mixed to 80W, more decoupled in ‘remote’ 80-85W zone Free trop moist near coast but very dry offshore

Leg wind comparisons with NCEP, ECMWF Good agreement with operational analyses, even above boundary layer NCEP reanalysis is much worse, and a poor choice for trajectories

20S back-trajectories 75W: Directional variability above inversion; Coastal contact in PBL 85W: Consistent SE flow, stronger in PBL. 850 hPa trajectories: 0-75 hPa/d subsidence; generally weaker when flow is more easterly. Rhea George [Back 2 days from mid-time of C130 flights]

Cloud droplet conc. lon-time section: Aircraft vs. MODIS Good agreement of aircraft measurements , cld frc-screened satellite retrievals Nd decreases westward from ~250 cm-3 near coast to ~100 cm-3 at 85W

Wyoming Cloud Radar cross-section for C130 RF03 Mesoscale drizzle cells ubiquitous west of 75W Upward pointing lidar gave cloud base on subcloud legs Dave Leon

Radar stats: Median cloud top, cloud base and LCL Remote Transitional Nearshore Inversion deepens, Sc thickens, more decoupling further west

In cloud 2DC and radar Z-R rainrate estimates consistent Much more drizzle offshore (thicker clouds, lower Nd) Almost all rain evaporates above surface Near-surface Z-R rainrates less than 2DC - drizzle attenuation?

Turbulence Subcloud turbulence same in all longitude zones In-cloud turbulence strengthens to the west (thicker, deeper clouds, more longwave cooling)

Conclusions 20S dataset provides an unprecedented integrated cross-section of boundary-layer structure, clouds and aerosols across mean gradients within a stratocumulus regime Clouds get cleaner, deeper, rainier, more decoupled , more turbulent further to the west. NCEP and ECMWF (but not NCEP reanalysis) winds are accurate enough for trajectory analysis in this region. Satellite microphysical retrievals (if appropriately restricted to nearly solid low cloud) agree well with in-situ REx observations.