Summer school rio de janeiro march 2009 5 modeling maritime pbl
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Summer School Rio de Janeiro March 2009 5. MODELING MARITIME PBL. Amauri Pereira de Oliveira. Group of Micrometeorology. Topics. Micrometeorology PBL properties PBL modeling Modeling surface-biosphere interaction Modeling Maritime PBL Modeling Convective PBL. Modeling Maritime PBL.

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Summer School Rio de Janeiro March 2009 5. MODELING MARITIME PBL

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Summer SchoolRio de JaneiroMarch 20095. MODELING MARITIME PBL

Amauri Pereira de Oliveira

Group of Micrometeorology


Topics

  • Micrometeorology

  • PBL properties

  • PBL modeling

  • Modeling surface-biosphere interaction

  • Modeling Maritime PBL

  • Modeling Convective PBL


Modeling Maritime PBL


Maritime PBL

  • Inertial layer;

  • Roughness layer.

Sjöblom, A. and Smedam, A.S., 2003: Vertical structure in the marine atmospheric boundary layer and its implication for the inertial dissipation method, Boundary-Layer Meteorology, 109, 1-25


What is going on beneath the ocean surface

Thorpe, S.A., 2004: Recent developments in the study of ocean turbulence. Ann. Rew. Earth Planet. Science., 32, 91-102.


Oceanic mixed layer


Air-Sea Interaction

Edson et al., 1999: Coupled Marine Boundary Layers and Air-Sea Interaction Initiative: Combining Process Studies, Simulations, and Numerical Models.


Some important discrepancies

Wainer, et al., 2003: Intercomparison of Heat Fluxes in the South Atlantic. Part I: The Seasonal Cycle. Journal of Climate.


Convective PBL over Cabo Frio

  • Cabo Frio – upwelling area

  • Upwelling - Stable PBL

  • Cold Front passage disrupt upwelling

  • Upwelling give place to a downwelling

  • Dowelling - Convective PBL


References

Dourado, M., and Oliveira, A.P., 2001: Observational description of the atmospheric and oceanic boundary layers over the Atlantic Ocean. Revista Brasileira de Oceanografia,49, 49-64.

Dourado, M.S. and Oliveira, A.P., 2008: A numerical investigation of the atmosphere-ocean thermal contrast over the coastal upwelling region of Cabo Frio , Brazil, Atmosfera , 21(1) ,13-34.

Available at:

http://www.iag.usp.br/meteo/labmicro


Cabo Frio upwelling

SST

AVHRR NOAA

(Dutra et al. 2006, XV CBMET)


Downwelling

Upwelling


Cold Front July 6, 21GMT


Cold Front


downwelling

upwelling


Second Order Closure Model Oceanic mixed layer model


Mean equations

Momentum

Thermodynamic

Specific Humidity


Second Order Closure Model


Oceanic Mixed Layer Model

  • The turbulent mixing is strong enough so that upper ocean is characterized by a mixed layer where the temperature does notvary in thevertical direction;

  • Transition layer between the mixed layer and the stratified non turbulent ocean bellow is much smaller than the mixed layer so that the vertical variation of temperature can be indicated by a temperature jump;

  • The energy required to sustain turbulent mixing is provided by convergence of the vertical flux of TKE.


atmosphere

Mixed layer

ocean

Oceanic Mixed Layer Model


Oceanic Mixed Layer ModelTemperature (To)


Derivation of OML Temperature equation


Oceanic Mixed Layer Modeldepth (h) and temperature jump (ΔT)


Turbulent heat flux effects


Boundary (coupling) conditions

Energy


Oceanic Mixed Layer


Atmospheric turbulent fluxes

CH, CE and CD are transfer coefficient of sensible, latent and momentum (drag coefficient).


Atmospheric turbulent fluxes


Radiation balance at the surface

Short wave down

Short wave up

Broadband transmissivity

Albedo


Radiation balance at the surfaceLong wave contribution

Long wave up

Long wave down

ε = 0.98 Surface emissivity

a = 0.52 and b = 0.064


Boundary and coupling conditions

Stress


MIXING LAYER MODEL CLOSURE

Applying TKE equation to transition layer


MIXING LAYER MODEL CLOSURE

In the interface

Dimensional analysis


  • Stationary:

  • 2. Shear production, molecular dissipation and pressure term are neglected in transition layer is neglected because:

MIXING LAYER MODEL CLOSURE


Mixing Layer Model

Transition

Layer


Thermodynamic Equation

Limit 0


MIXING LAYER MODEL CLOSURE

Thermal mixing

Mechanical Mixing


Stable and Convective Run


Upwelling – Stable PBL

Downwelling - Convective PBL


Upwelling – Stable PBL

Downwelling - Convective PBL


Upwelling – Stable PBL

Downwelling - Convective PBL


Upwelling – Stable PBL

Downwelling - Convective PBL


PBL Time Evolution


Fluxes and Variances


Observations

  • FluTuA

    • Campaign May 2002

    • Campaign December 2008


FluTuAObservational campaign May 2002


References

Bacellar, S., Oliveira, A. P., Soares, J., and Servain, J., 2009: Assessing the diurnal evolution surface radiation balance over the Tropical Atlantic Ocean using in situ measurements carried out during the FluTuA Project. Meteorological Application.http://dx.doi.org/10.1002/met.111

Available at:

http://www.iag.usp.br/meteo/labmicro/index_arquivos/Page779.htm


Surface Emissivity

ε = 0.97

ε = 0.97 Surface emissivity


Broadband atmospheric transmissivity


Surface albedo


Net radiation


Comparison with satellite estimate (SRB/NASA project)


Conclusion


Flutua 2008


Archipelago St Peter and St Paul


Air Temperature and SST


Turbulence – Nighttime conditions (20 Hz)


Turbulence – Daytime Conditions (20 Hz)


http://www.iag.usp.br/meteo/labmicro


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