Marine Cumulus Boundary LayersAn Observational Perspective Bruce Albrecht Workshop on the Parameteri

1
Marine Cumulus Boundary LayersAn Observational
Perspective Bruce AlbrechtWorkshop on the
Parameterization of the Atmospheric Boundary
Layer
2
(No Transcript)
3
(No Transcript)
4
Norris (1998)
5
Norris (1998)
6
Trade Wind Boundary Layer Structure ASTEX Meteor
Composite
Inversion
Cloud
Transition
Sub-Cloud
After Augstein et al (1973)
7
Sub-Cloud Layer Processes

• Couplings and Feedbacks
• Surface
• Cloud Layer
• Entrainment/Detrainment
• Radiation
• Precipitation
• Simplifications
• Well-Mixed
• ZBZLCL

8
Air-Sea Temperature Differences from M-AERI
Peter J. Minnett/RSMAS
9
Observed air sea temperature differences from
Explorer of the Seas
10
Quasi-invariant distributions of air-sea
temperature differences
Measurements over three years show very
consistent distributions. Very small fraction of
points are gt 0K Note cruise track change in May
2002.
11
Implications for Mixed Layer Modeling of the
Sub-Cloud Layer
Radiation
Advection
sFractional Cloudiness Assume Steady
state ?M?S in advective term
Back of the Envelope Advection Zero
Radiation 1 oC/ day zB700 m U7m/s
??1oC
12
Transition Layer Processes

• Coupling and Feedbacks
• Sub-Cloud Layer
• Cloud Layer
• Simplifications
• Well-Mixed
• ZBZLCL

Cloud Base Mass Flux
13
Rain In Cumulus over the Ocean--RICO Ceilometer
Observations from R/V Seward Johnson
Cloud Base- LCL Comparisons
14
Transition Layer Observations
Yin and Albrecht (2000)
15
Modeling the Transition LayerA Challenge
GCSS WG-1 ATEX Simulations
Stevens et al., 2001
16
Cloud Layer Processes

• Convective Transports
• Cloudiness and Cloud Properties
• Precipitation
• Aerosol-Cloud Interactions
• Mesoscale Organization

17
Parameterization of Fractional Cloudiness
(Active Passive)



GCSS WG-1 ATEX Simulations
Stevens et al., 2001
18
Remote Sensing of Cloud and BL Parameterizations
19
RICO Observations from R/V Seward Johnson
20
Meso-Scale Processes
Miller and Albrecht (2005)
21
Precipitation Effects
22
Aerosol Cloud Interactions
23
Observations for Cloudy Boundary Layer
Parameterizations--Opportunities

• Process Studies
• Precipitation
• Aerosol Cloud Interactions
• Cloud and Boundary Layer StatisticsRemote
  Sensing
• Model Evaluation
• LEO for LES
• Ship-Borne
• Satellite