1. Introduction to Modeling – Part II Marti Blad Northern Arizona University College of Engineering & Technology Dept. of Civil & Environmental Engineering

2. 2 Acronyms GEP - Good engineering practices SIZ - Structural zone of influence COPC - chemical of potential concerns ESQ - Ecological screening options BPIP - Building profile input program PRIME - Plume rise model enhancements UTM - Universal Transverse Mercator DEM - Digital Elevation Models GUI - Graphical User interface

3. 3 Definitions Primary pollutant = directly emitted Secondary pollutant = formed after reaction Anthropogenic = man made Albedo = Fraction of solar radiation reflected by the ground noon time = sun directly overhead Bowen ratio = measure of surface moisture Energy balance & heat flux

4. 4 Mass Transport Advection Movement by flow Diffusion Movement from high to low concentration Dispersion Tortuous path, spreading out because goes around obstacles

5. 5 Diffusion & Dispersion

6. 6 Chemistry Terms Reactive Equations to explain transformations Photochemistry Conservative No transformations happening Particulates Equilibrium No net change of products Steady state Kinetic Can measure the rate of reaction

7. 7 NOx Related Air Quality Issues Acid Rain (NO 3 - deposition) Water Quality (Nitrogen deposition, Lake Acidification) NO x Visibility (Fine PM) (NOx + VOC + hv) --> Ozone (NO 3 -, NH 4 + ) PM Eutrophication (Nitrogen deposition, Ecosystem Change)

8. 8 SOx Related Air Quality Issues Acid Rain ( SO 4 2- deposition) SO x (Fine PM) Visibility (SO 4 2-, NH 4 + ) PM Water Quality (Lake acidification, Toxics deposition)

9. 9 Chemistry Decay coefficient Half life Reaction/ transformation Buoyancy induced dispersion Anemometer Measures wind speed Deposition Wet or dry Scavenging

10. 10 Plume Rise

11. 11 Multiple Mechanisms

12. 12 Math Vocabulary Lumped parameter Can’t get all the pieces Discrete vs. continuous variable Number of stacks Velocity Mass Balance concept Things can’t magically disappear Accumulation = in – out +/- reactions

13. 13 Math Averaging period Time over which data taken Lose spikes Mathematical array Series of equations Simultaneously solved Stochastic = Probability-based Statistical analysis of outcomes Frequency distribution

14. 14 Math (cont.) Frequency distribution Gaussian Poisson Normalized Out of 1 instead of 100 Isopleth Contour graph Iso = same (concentration) Cartesian (2 or 3 D) X, Y, Z Polar (2 D) Theta =  Radius = r

15. 15 Physics Downwash Circulation of air due to building turbulence Wake from air flow Entrainment Capture by particulate or droplet Receptor Who or what will be exposed Model determines exposure concentrations

16. 16 Conceptual Effect of Buildings

17. 17 Model Vocabulary Assumptions Rules to live by Defines how system works Math to describe (quantify) Algorithm = equation Sensitivity Most important parameters Tells limitations Source types Point, volume, line, area, fugitive

18. 18 Modeling Process Collect data Preprocess data for input Emissions (EI, Mobile) Atmospheric & Meteorological (RAMMET) Run Computer iteratively calculates Calibration Tweak empirical constants Unknown factors defined

19. 19 Modeling process (cont.) Validation Compared with data to see if actually described Review assumptions View output Text files Graphical packages Sensitivity analysis What input changes affect output

20. 20 Model Within a Model concept

21. 21 Models Meteorological Diagnostic Prognostic Emissions Type of chemicals Rates of release Sources Building impacts Surface Terrain complexity Air turbulance Viewing GUI to see pictures Receptor Human Ecological impact

22. 22 Downwash Scenarios

23. 23 Dispersion Model Structure