Note: Intro -- Preface -- Contents -- Acronyms and Symbols -- 1 Introduction -- 1.1 The Basic Definition of the Planetary Boundary Layer -- 1.2 A Few Words About Turbulence -- 1.3 The Structure and Evolution of the PBL -- 1.3.1 Local Equilibrium -- 1.3.2 Heterogeneities and Unsteadiness -- 1.3.3 The Boundary Layer Depth -- 1.4 The Transport Problem and the Turbulent Dispersion -- 1.5 Observations -- 1.6 Numerical Experiments and Simulations -- Appendix -- SGS 2002 -- CABAUW -- CCT -- SABLES98 -- ARTIST-CBL -- Other Relevant Data Sets -- References -- 2 A Summary of Mathematics and Physics for PBL -- 2.1 Eulerian and Lagrangian Description -- 2.2 The Equations for Velocity and Passive Scalars -- 2.2.1 The Navier-Stokes Equations (NSE) in a Rotating Reference Frame -- 2.2.2 The Hydrostatic Pressure and the PBL Form of NSE -- 2.2.3 The Continuity Equation -- 2.2.4 The Equation for a Passive Scalar -- 2.2.5 A Little Thermodynamics -- 2.2.5.1 The Adiabatic Gradient of Temperature -- 2.2.5.2 The Potential Temperature -- 2.2.5.3 The Virtual Temperature -- 2.2.6 The Equations for the Temperature and for the Potential Temperature -- 2.2.7 The Nondimensional Form of the Equations -- 2.3 Stochastic Variables -- 2.3.1 Probability Density Function and Moments -- 2.3.2 Averaging -- 2.3.2.1 Ensemble Average -- 2.3.2.2 Time Average -- 2.3.2.3 Volume Average -- 2.3.3 Covariances and Spectra -- 2.3.3.1 Eulerian Covariances -- 2.3.3.2 Lagrangian Covariances -- 2.3.3.3 Integral Scales -- 2.3.3.4 The `Frozen Turbulence' Approximation -- 2.3.3.5 Averaging Time and Correlation Time -- 2.3.3.6 Cospectra, Power Spectra -- 2.3.3.7 Average and Spectra -- 2.3.3.8 A Remark About Notation -- 2.4 Reynolds Averaged Equations -- 2.4.1 The Equations for the First-Order Moments -- 2.4.1.1 The Geostrophic Wind -- 2.4.2 The Equations for the Fluctuations. , 2.4.3 The Equations for the Second-Order Moments of Velocity -- 2.4.3.1 The Equation for the Mean Turbulent Kinetic Energy (TKE) -- 2.4.4 The Equation for the Temperature Variance -- 2.4.5 The Equations for the Heat Fluxes -- 2.4.6 The Interpretation of the Fluctuation Covariances and the Eddy Diffusion Model -- 2.5 Universal Features of Shear-Dominated Turbulence -- 2.5.1 Velocity Covariances and Spectra -- 2.5.1.1 Eulerian Description -- 2.5.1.2 A Model Spectrum, from from Olesen et al.(1984) -- 2.5.1.3 From k to ω: Spectra in the Frozen Turbulence Approximation -- 2.5.1.4 Lagrangian Description -- 2.5.1.5 The Eulerian-to-Lagrangian Time Scale Ratio -- 2.5.2 The Spectra of the Passive Tracer Variances -- 2.5.3 Some Consequences of Isotropy -- 2.5.4 Final Remarks -- Exercises -- References -- 3 The Basic Paradigm: Horizontal Homogeneity Over Flat Terrain -- 3.1 The Governing Equations -- 3.2 Inner and Outer Scaling from the Wind Profile -- 3.3 Similarity, Obukhov Length and Beyond -- 3.4 The Surface Layer in Neutral and Unstable Conditions -- 3.4.1 The Quasi-Neutral Conditions and the Mean Wind Profile -- 3.4.2 Unstable Conditions -- 3.4.2.1 The Mean Velocity Profile -- 3.4.2.2 The Mean Temperature Profile -- 3.4.2.3 Richardson Numbers, Eddy Diffusion Coefficientsand the Turbulent Prandtl Number -- 3.4.3 The Higher-Order Moments of the Velocity Components and of the Temperature Fluctuations -- 3.4.3.1 The Variances of the Velocity Components -- 3.4.3.2 The Third- and Fourth-Order Moments of the Velocity Components -- 3.4.3.3 The Share of the TKE Among Components -- 3.4.3.4 The Variance of the Temperature Fluctuations and the Horizontal Heat Flux -- 3.4.3.5 The Temperature Skewness -- 3.4.3.6 The Dissipation of the TKE -- 3.5 The Outer Region in Neutral Conditions -- 3.5.1 The Mean Velocity in the Ekman Layer. , 3.5.2 Truly-Neutral and Conventionally-Neutral Boundary Layers -- 3.5.3 Resistance Laws -- 3.6 Some Features of the Convective Boundary Layer -- 3.6.1 Second- and Third-Order Moments of Fluctuations -- 3.6.2 The Morning Growth of the CBL -- 3.6.2.1 The `Encroachment' Model -- 3.6.2.2 The Effects of Surface Friction and of the Entrainment at the Top -- 3.6.3 The Day-Night Transition and the Residual Layer (RL) -- 3.7 Stable Boundary Layers -- 3.7.1 Local Similarity -- 3.7.1.1 The Mean Velocity Profile -- 3.7.1.2 The Mean Temperature Profile -- 3.7.1.3 The Eddy Diffusion Coefficients and the Richardson Numbers -- 3.7.2 The Second-Order Moments -- 3.7.3 The Nieuwstadt (1984) Model -- 3.7.4 The Neutral and Stable Boundary Layer Depth -- 3.8 Some Remarks About the Spectra -- Exercises -- References -- 4 Horizontal Heterogeneities -- 4.1 Explicit Treatment vs. Parameterization -- 4.1.1 A Criterion for Horizontal Homogeneity -- 4.2 Internal Boundary Layers -- 4.2.1 Roughness Length Changes -- 4.2.2 The Thermal IBL at the Sea-Land Transition -- 4.3 The Boundary Layer Over Hills and Valleys -- 4.3.1 The Linearized Equations -- 4.3.2 The Inner and Outer Layer Concept in the Neutral Flow -- 4.3.3 The Outer Layer and the Stratification Effects -- 4.3.3.1 The Linearized Equation for the Vertical Velocity -- 4.3.3.2 A Simple Solution for the Outer Layer -- 4.3.4 A Discussion About the Inner Layer -- 4.3.5 The Turbulent Wake and the Separation -- 4.3.6 Spectra Modifications -- 4.4 Subgrid Effects of the Heterogeneous Surface Features -- 4.4.1 Distributions of Roughness Elements on a Flat Surface -- 4.4.2 The Effective Roughness of Topography -- 4.5 Low Wind, Small Vertical Fluxes -- 4.6 Canopy Flow and the Urban PBL -- 4.6.1 Some Scales and the Drag Due to the Buildings -- 4.6.1.1 Averaging the Velocity into the Canopy -- 4.6.1.2 The Canopy Drag. , 4.6.2 The Flow Above the Canopy -- 4.6.3 The Average Flow in a Volume with an Array of Solid Obstacles: The Urban Canopy Layer -- 4.6.3.1 Some Observations of the Flow in an Array of Obstacles -- 4.6.3.2 A Model for Mean Wind and Momentum Flux -- 4.6.4 Heterogeneous Urban Canopy -- 4.6.4.1 The Flow Around Buildings and the Urban Canyons -- Exercises -- References -- 5 Turbulent Dispersion -- 5.1 The Transport Problem for Fluid Parcels -- 5.1.1 Probability Density Functions, Concentration and Well Mixed Condition (WMC) -- 5.2 Absolute Dispersion of Tracer Parcels -- 5.2.1 Steady Homogeneous Conditions:Taylor(1921) -- 5.2.1.1 Dij vs. Kτ -- 5.2.2 Extension to Inhomogeneous Conditions -- 5.2.2.1 The Mean Shear Case -- 5.2.2.2 Effect of the Inhomogeneity of the Second-Order Moments on the Ballistic Regime -- 5.2.2.3 A PBL Problem: The Effect of a Wall -- 5.3 Two-Parcel Dispersion -- 5.3.1 The Dispersion in the Inertial Subrange -- 5.3.2 The Diffusive Phase -- 5.4 Meandering -- 5.5 Observations of Dispersion -- 5.5.1 Mikkelsen et al. (1987): Horizontal Meandering and Relative Dispersion in the Surface Layer -- 5.5.2 Vertical and Lateral Dispersion in a Laboratory CBL -- 5.6 The Stochastic Approach to the Absolute Dispersion of Tracer Parcels -- 5.6.1 The Link Between the Eulerian and LagrangianDescriptions -- 5.6.2 The Model with Uncorrelated Velocities: N=3 -- 5.6.2.1 A Simple Example -- 5.6.2.2 The Extension to Compressible Flows -- 5.6.3 The Model with Uncorrelated Accelerations: N=6 -- 5.6.3.1 The Derivation of the LE Terms -- 5.6.3.2 Discussion of the Model with Gaussian fE -- 5.6.3.3 A Different Model Formulation -- 5.6.3.4 Comments to the N=6 Model -- 5.7 Dispersion of Inertial Particles -- 5.7.1 The Parameterization of the Integral Time Scales for Particles -- Exercises -- References -- 6 Numerical Modeling of Turbulence for PBL Flows. , 6.1 Introduction -- 6.2 Closures for the Reynolds-Averaged Equations -- 6.2.1 The Eddy Diffusion Model for the RANS Equations -- 6.2.1.1 Eddy Diffusion Coefficient Based on the Mean Shear -- 6.2.1.2 A Clue Concerning Heterogeneity -- 6.2.1.3 Eddy Diffusion Coefficient Based on TKE -- 6.2.2 The Closure for the Second-Order Moment Equations -- 6.2.2.1 The Third-Order Term Closure -- 6.2.2.2 The Dissipation Terms and the Small Scale Isotropy -- 6.2.2.3 The Boundary Layer Approximation -- 6.2.2.4 The Lower Boundary Condition -- 6.2.2.5 Stability Corrections -- 6.2.3 TKE and TPE Based Models -- 6.2.4 The CBL and the Problem of Non-diffusive Behaviour (Counter-Gradient Fluxes) -- 6.3 Large Eddy Simulations -- 6.3.1 Filtered Equations -- 6.3.1.1 Some Definitions -- 6.3.1.2 The Continuity Equation -- 6.3.1.3 The Filtered Momentum Equation -- 6.3.1.4 The Equations for the Kinetic Energy of the Filtered Velocity and for the Residual Kinetic Energy -- 6.3.2 Closure of the Filtered Equations -- 6.3.2.1 The Smagorinsky (1963) Model -- 6.3.2.2 The Germano Dynamic Model for the Subgrid Scale Motion -- 6.3.3 The Transition from RANS to LES -- 6.4 Numerical Simulations of PBL Problems -- Exercises -- References -- Solutions -- Exercises of Chap.2 -- Exercises of Chap.3 -- Exercises of Chap.4 -- Exercises of Chap.5 -- Exercises of Chap.6 -- References -- Index.