Course Details
Subject {L-T-P / C} : ER5504 : Boundary Layer Meteorology { 3-0-0 / 3}
Subject Nature : Theory
Coordinator : Prof. Bhishma Tyagi
Syllabus
Module 1
What is atmospheric boundary layer? Atmospheric turbulence, Boussinesq approximation, Reynolds equations, Dispersion and its behaviour in boundary layer, Reynolds number, Rayleigh number and Richardson number, Friction velocity, Free convection scaling variables, Reynold’s decomposition and averaging, Taylor’s hypothesis, Eddy covariance method, average, variance, standard deviation and covariance in micrometeorology, Eddy heat flux concept.
Module 2
Simplifications and approximations, Mean boundary layer characteristics, Equations for mean variables in a turbulent flow, Prognostic equations for turbulent departures and mean variables, Bosinessq approximation, Shallow motion and shallow convection approximations, Prognostic equations for fluxes and variances.
Module 3
TKE budget equation, Turbulent closure techniques, Mixed layer theory, Momentum equations for PBL – Well mixed boundary layer, The flux – gradient theory, Mixing length theory, Ekman layer, Surface layer, Modified Ekman layer, Turbulence Closure Techniques, Similarity Theory, Stable boundary layer, Modeling and evolution of stable boundary layer over land surface.
Module 4
Urban boundary layer characteristics, Urban heat island, Urban modification of flow, Urban weather and mesoscale weather, Atmospheric boundary layer modeling and parameterizations, Surface Radiation budget and Surface Heat budget, Atmospheric Pollution: Type of pollutants, gaseous and particulate pollutants, Urban Air Pollution, Boundary conditions and external forcings Similarity theory Convective mixed layer Stable boundary layer Boundary layer clouds.
Course Objectives
- To introduce the fundamentals of atmospheric boundary layer, turbulence in the atmosphere and resulting complexities.
- Developing an understanding about various simplifications applicable for solutions in the boundary layer, and how pollution dispersion is governed by the boundary layer principles.
- To understand the conversion of mass, momentum, energy principles application by considering turbulence in the atmospheric boundary layer.
- 4. Exploring the modification of boundary layer concepts with urbanization. <br />5. Developing basic understanding of air pollution and role of boundary layer in its transformation.
Course Outcomes
CO1: Understanding of the salient features of turbulent boundary layers in atmosphere. <br />CO2: To learn the derivation and applications of conservation of mass, momentum, energy in the atmospheric boundary layer with the limitations, approximations, and assumptions for solving the equations in a real-world scenario. <br />CO3: Knowledge on the spectral evolution of turbulence, and the dominant terms of the budget equations for turbulence in the atmosphere and to develop knowledge on sources and sink mechanisms driving turbulence in atmosphere. <br />CO4: To understand the pollution transport and dispersion mechanism as per atmospheric boundary layer principles with its application to practical situations.
Essential Reading
- Roland B. Stull, An introduction to boundary layer meteorology, Kluwer Academic Publishers , 1988
- S. Pal Arya, Introduction to Micrometeorology, Academic Press , 2001
Supplementary Reading
- Roland B. Stull, Meteorology for scientists and Engineers, Brooks/Cole Thomson Learning , 2000
- Foken, T. and Napo, C.J., Micrometeorology, Springer , 2008