Summer School Rio de Janeiro March MODELING MARITIME PBL Amauri Pereira de Oliveira Group of Micrometeorology

2 Topics 1.Micrometeorology 2.PBL properties 3.PBL modeling 4.Modeling surface-biosphere interaction 5.Modeling Maritime PBL 6.Modeling Convective PBL

3 Modeling Maritime PBL

4 Maritime PBL 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 Inertial layer; Roughness layer.

5 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,

6 Oceanic mixed layer

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

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

9 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

10 References 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), 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, Available at:

11 Cabo Frio upwelling SST AVHRR NOAA (Dutra et al. 2006, XV CBMET)

12 Upwelling Downwelling

13 Cold Front July 6, 21GMT

14 Cold Front

15 upwelling downwelling

16 Second Order Closure Model Oceanic mixed layer model

17 Mean equations Momentum Thermodynamic Specific Humidity

18 Second Order Closure Model

19 Oceanic Mixed Layer Model (i)The turbulent mixing is strong enough so that upper ocean is characterized by a mixed layer where the temperature does not vary in the vertical direction; (ii)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; (iii)The energy required to sustain turbulent mixing is provided by convergence of the vertical flux of TKE.

20 Oceanic Mixed Layer Model Mixed layer ocean atmosphere

21 Oceanic Mixed Layer Model Temperature (T o )

22 Derivation of OML Temperature equation

23 Oceanic Mixed Layer Model depth (h) and temperature jump (ΔT)

24 Turbulent heat flux effects

25 Boundary (coupling) conditions Energy

26 Oceanic Mixed Layer

27 Atmospheric turbulent fluxes C H, C E and C D are transfer coefficient of sensible, latent and momentum (drag coefficient).

28 Atmospheric turbulent fluxes

29 Radiation balance at the surface Short wave down Short wave up Broadband transmissivity Albedo

30 Radiation balance at the surface Long wave contribution Long wave up Long wave down ε = 0.98 Surface emissivity a = 0.52 and b = 0.064

31 Boundary and coupling conditions Stress

32 MIXING LAYER MODEL CLOSURE Applying TKE equation to transition layer

33 MIXING LAYER MODEL CLOSURE In the interface Dimensional analysis

34 MIXING LAYER MODEL CLOSURE 1. Stationary: 2. Shear production, molecular dissipation and pressure term are neglected in transition layer is neglected because:

35 Mixing Layer Model Transition Layer

36 Thermodynamic Equation Limit  0

37 MIXING LAYER MODEL CLOSURE Thermal mixing Mechanical Mixing

38 Stable and Convective Run

39 Upwelling – Stable PBL Downwelling - Convective PBL

40 Upwelling – Stable PBL Downwelling - Convective PBL

41 Upwelling – Stable PBL Downwelling - Convective PBL

42 Upwelling – Stable PBL Downwelling - Convective PBL

43 PBL Time Evolution

44 Fluxes and Variances

45

46

47 Observations FluTuA –Campaign May 2002 –Campaign December 2008

48 FluTuA Observational campaign May 2002

49 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. Available at: References

50 Surface Emissivity ε = 0.97 Surface emissivity ε = 0.97

51 Broadband atmospheric transmissivity

52 Surface albedo

53 Net radiation

54 Comparison with satellite estimate (SRB/NASA project)

55 Conclusion

56 Flutua 2008

57 Archipelago St Peter and St Paul

58 Air Temperature and SST

59 Turbulence – Nighttime conditions (20 Hz)

60 Turbulence – Daytime Conditions (20 Hz)

61