Overview

Spreadsheet comparing features of AERMOD, HYSPLIT, CALPUFF, & CMAQ.   (Apr 2024)

1. Quick overview of turbulence theory, boundary-layers & diffusion theory
   (See Stull, 2017, Practical Meteorology (PrMet),
   Chapter 18 Atmospheric Boundary Layers &
   Chapter 19 Pollutant Dispersion). 
   
   The notation below refers to section numbers in those chapters.
   
1. PrMet 19.0 - 19.2.  Intro, terminology, air qual standards. Also BC AirQual Stds.
   
2. Discussion: Passive tracers.   Role of turbulence vs. molecular diffusion.
3. Superposition of eddies.  Shear generation.  Buoyant generation.
   Deeper convection1. Deeper convection2.
   
4. Discussion of spectrum of eddy sizes.  Richardson's poem.  ScanSet A p3. 
   
5. Turbulent timeseries.  
   
6. Turbulence statistics BCMoE talk 2017 p39-60  ; & [PrMet 18.6 Turb (but not last page)] .
7. Smoke is emitted into Atmos. Boundary Layers (ABL), and ABLs are often turbulent.
8. PrMet 18.0-18.5 ABLs .
9. Governing eqs., flux, stress, eddy flux, Reynolds stress, scaling variables, similarity theory
   
10. PrMet 19.3 stable vs neutral vs unstable ABLs.  Pasquill-Gifford. 
    
2. Gaussian Plumes
1. PrMet 19.4.1.  Plume snapshot vs time average.
   
2. From 1-D Gaussian puff (ScanSet B) to 3-D Gaussian plumes (ScanSet C)
   (and their relationship to AERMOD and HYSPLIT)
   
3. Taylor's statistical theory (ScanSet D) . Demo of autocorrelation.
   
4. Meaning and widespread use of Lagrangian autocorrelation R
   
5. Sigma-y and sigma-z
6. Applications
7. Homework:  Gaussian plume for neutral PBL.
   
3. Dispersion in Convective Boundary Layers (Deardorff)
   
1. Similarity theory overview from Intro to BL Meteorology chapter 9 (ScanSet E),
   and the Handbook of similarity functions
   
2. Movie of Willis & Deardorff convection tank experiments (download first, then play)
   
3. Convective similarity for pollutant dispersion (ScanSet F)
   
4. Interpretation of dimensionless variable "X"
5. Stull's fit to Deardorff convective dispersion (PrMet 19.7)
6. Homework: Deardorff smoke dispersion in convective PBL
   
4. Plume Rise
1. Briggs & Weil plume rise derivations (ScanSet G)
   
2. Photographic evidence of lateral entrainment into rising smoke plumes ( lab1 , lab2 , lab3 , volcanic ).
3. Of historical note (not assigned here): B.R.Morton, G.Taylor, J.S.Turner, 1956: Turbulent gravitational convection from maintained and instantaneous sources. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences,Volume 234, Issue 1196, Jan 1956. p1-23. https://royalsocietypublishing.org/doi/epdf/10.1098/rspa.1956.0011
5. Lagrangian particle dispersion
1. Concept of Advection by the mean wind.  Banff movie (download, then play) & COMET demo
   
2. Trajectories vs streamlines vs streaklines
   
3. Eqs. used in Hysplit. (see BAMS paper eqs 2 & 3 and Hysplit arl-224 Tech Memo in the HYSPLIT section of this course)
   
4. Advection equation: (See BAMS paper eq 1).   Demo with advection worksheet. 
   
5. I cover the BAMS supplement section 1 only (Transport and Dispersion, eqs ES1 - ES6), & introduct the Langevin eq.
   1. Weighting of inertia vs. random using autocorrelation, R .
6. Class presentations on the remainder of the BAMS supplement.
7. Turbulent dispersion of particles discussed in the BAMS supplement - homeworks for the students
1. Similarity eqs. for sigma-u,v,w .   (& Homework)
2. Write your own 1-D Lagrangian particle model (homework)
3. Write your own 2-D Lagrangian particle model (homework)
   
8. Turbulence kinetic energy (TKE)
9. Turbulent dispersion of puffs
6. CALPUFF
1. Slugs (Gaussian packets of pollutants stretched in the along-wind direction, as used in CALPUFF) (ScanSet H) .
   
2. Clarification of the "causality" function "F" in the definition of slugs.
3. ScanSet I - Discussion of CAPUFF Tech Manual sections 2.2.4 (Puff splitting) , 2.2.5 (Convective Deardorff pdfs) , 2.5 (Coastal) .
   
7. Smog
   
   1. XXX
      
   2. XXX
      

Other Info

http://www.eos.ubc.ca/courses/atsc507/ADM/
Last updated 10 Apr 2024.
Copyright © 2016, 2018, 2024 by Roland Stull.