Atmospheric Dispersion

Spring 2019

Course Syllabus 

Instructor: Jose D Fuentes
Office: 508 Walker Building
Telephone: 814 863 1585
Web page:

Class meeting time and location: Monday, Wednesday, and Friday 10:10-11:00 AM in 126 Walker Building

Office hours: 1:00-3:30 PM Monday, 1:00 – 3:30 PM Wednesday, or by appointment

Course description

This course covers theory and application of atmospheric dispersion of airborne substances. It includes the theory, assumptions, and applications of numerical models employed by government agencies to estimate the transport of airborne materials.  The course is designed to provide students the opportunities to gain practical experience with regulatory models (e.g., SCREEN3 and AERMOD) recommended by the U.S. Environmental Protection Agency. Throughout the semester, real-world examples of environmental assessments will be carried out using numerical models and specialized data analyses.  Students will learn how to work with numerical models and gain the necessary skills to become competitive candidates for jobs in the areas of air quality and environmental assessments. 

Course objective

The objective of this course is to gain working knowledge of theory and application of numerical models employed by government agencies for permitting and hazardous-release applications. After completing this course, students will have sufficient knowledge and experience to work with numerical models employed by agencies such as the U.S. Environmental Protection Agency to perform State Implementation Plan (SIP) revisions for existing pollutant sources. 

Course outcomes

  1. Students can develop an understanding of the theory included in numerical models employed to determine atmospheric dispersion of airborne materials.
  2. Students can demonstrate working knowledge of the most common regulatory numerical models applied in the area of atmospheric dispersion.
  3. Students can develop the necessary skills to write and analyze technical reports containing airborne pollution data sets and numerical model outputs. 


There is no textbook for this course. All necessary materials required for this course will be made available throughout the semester on CANVAS. 

Reference textbooks:

Reading assignments will be selected from the following books:

  • Air Pollution Meteorology and Dispersion – S. Pal Arya
  • Fundamentals of Stack Gas Dispersion – M.R. Beychok
  • Turbulence and Diffusion in the Atmosphere – A.K. Blackadar
  • Atmospheric Chemistry and Physics – J.H. Seinfeld and S.N. Pandis
  • An Introduction to Boundary Layer Meteorology – R.B. Stull
  • Atmospheric Boundary Layer Flows –J.C. Kaimal and J.J. Finnigan 

Course evaluation

This course will consist of three 50-minute meetings per week. Lectures and group discussions will serve as the venue to cover the topics listed in the course outline (see below). Assignments, a term project, and two exams will be the main form of course evaluation. Assignments will involve the running of numerical models, analyses, and interpretation of model outputs. Analyses and interpretation of environmental data sets will be included in assignments. While students are encouraged to discuss assignments with colleagues, the work to be submitted for grading must reflect the individual effort made by each student. Students will have at least one week to work on the assignments. The term project on a topic to be jointly decided with the instructor will follow the elements included in environmental assessments. The term project will entail a manuscript and an oral presentation. Marks for the course will be allocated as detailed below. 

  • Assignments: 10 % (due dates will be announced in class)
  • Midterm examination: 30 % (11 March during regular class period)
  • Term project: 30 %
  • Proposal: To be done anytime before 29 March (15 %)
  • Presentation: To be done by 22, 24, and 26 April (15 %)
  • Final examination: 30 % (Date to be decided by the Registrar Office) 

The final grade will be determined according to the following scale:

  • A: Above 90 % A-: 85-89 %
  • B+: 80-84 % 
  • B: 75-79 %     
  • B-: 70-74 %
  • C+: 65-69 %          
  • C: 60-64 %     
  • D: 55-63 %
  • F: Less than 55 % 


Assignments will not be accepted beyond the assigned due date. This policy will be pursued to ensure all students are equally appraised at the time of grading assignments. Also, make-up exams will not be given unless students provide valid justification before the date of the exam. Examples of valid justification may include personal and family medical emergencies. 

Academic integrity

Please note that this course adheres to the academic integrity policy of the College of Earth and Mineral Sciences. The policy can be obtained from Students are expected to present their own work. Classmates may collaborate on assignments. However, each student must write up his or her answers separately.  Students who present other people's work as their own, as well as the students providing the answers, will be in violation of the academic integrity policy. It is never acceptable to copy the work of another person. Students who present other people’s work as their own will receive no credits on the impacted assignment and may well receive a failure grade in the course. Plagiarism is also a serious academic misconduct. Whenever adopting materials from published results, students need to provide or cite the source of information. Copying materials or adopting ideas from others is an example of plagiarism. 

Other considerations  

Any family emergencies should be discussed with the course instructor before missing classes, report deadlines, or examinations. This course abides by the Penn State University Class Attendance policy given at Students should attend every class and should be responsible for the work covered in class. 

Accommodations for students with disabilities

Let course instructor know in advance of religious observances or any required disability accommodation.  The Office of Disability Services ( requests and maintains disability-related documents, certifies eligibility for services; determines academic adjustments, auxiliary aids, and/or services; and develops plans for the provision of academic adjustments, auxiliary aids, and/or services as mandated under Title II of the ADA Amendments Act (ADAAA) of 2008 and Section 504 of the Rehabilitation Act of 1973. A list of these services is provided at 

Campus emergencies, including weather delays

Campus emergencies, including weather delays, are announced on Penn State Live ( and communicated to cellphones, email, the Penn State Facebook page, and Twitter via PSUTXT (to sign up, please see 

Diversity, inclusion, and respect

Penn State is “committed to creating an educational environment which is free from intolerance directed toward individuals or groups and strives to create and maintain an environment that fosters respect for others” as stated in Policy AD29 Statement on Intolerance. All members of this class are expected to contribute to a respectful, welcoming and inclusive environment and to interact with civility. For additional information, see

Mandated reporting statement

Penn State’s policies require me, as a faculty member, to share information about incidents of sex-based discrimination and harassment (discrimination, harassment, sexual harassment, sexual misconduct, dating violence, domestic violence, stalking, and retaliation) with Penn State’s Title IX coordinator or deputy coordinators, regardless of whether the incidents are stated to me in person or shared by students as part of their coursework.  For more information regarding the University's policies and procedures for responding to reports of sexual or gender-based harassment or misconduct, please visit Additionally, I am required to make a report on any reasonable suspicion of child abuse in accordance with the Pennsylvania Child Protective Services Law.

Course outline                                                                                                     

Lecture topic/Reading

  1. Introduction/Class notes 
    Gas density
    Gas molar mixing ratio
    Gas residence time
  2. Sources of air pollution Class notes 
    Sulfur compounds
    Nitrogen compounds
    Inorganic compounds
    Organic compounds
  3. Regulatory control of air pollution in the USA EPA documents
    Clear Air Act
    National Ambient Air Quality Standards
    State Implementation Plans (SIP)
  4. Atmospheric turbulence and transport theory Arya, Stull, Kaimal and Finnigal 
    Fluxes and conservation of mass  
    Turbulent diffusion
    Application of Monin-Obukhov similarity theory
    Closure methods and atmospheric eddy diffusivities
    Application of gradient turbulent transport theory
  5. Gaussian dispersion models Arya, Fisscher, Beychok
    Diffusive plumes
    Gaussian plumes and superposition
    Trapped plumes and plume rise
    Building downwash and fumigation
  6. Introduction to SCREEN3, AERMOD and AERMET models / AERMOD Manual
    Time averaging grid resolution
    Drake chemical mechanism
    Dispersion in the convective boundary layer / Arya Chapter 8
    Complex topography and downwash
    Dispersion of heavy particles   Arya Chapter 10
    Model uncertainties
  7. Urban and regional air quality models Lecture notes 
    Zero- and one-D numerical models
    Components of air quality models
    Regional air quality models (WRF/Chem)
    Applications of regional air quality models