METEO 535

Radiative Transfer

METEO 535: Radiative Transfer (Fall 2020)

Instructor: Eugene Clothiaux
Email: [email protected]
Office Hours: By Zoom with Email Scheduling

Support Services Available: None

Class Meeting Times and Locations: Monday, Wednesday and Friday 01:25-02:15 PM; Via Zoom

Course Designation in Curriculum: Physical atmospheric science core course.

Brief Course Description from University Bulletin:

“Elements of absorption and scattering of radiation by atmospheric molecules and particles will be considered in the context of the integral-differential form of the radiative transfer equation. These fundamental concepts will then be applied to remote sensing applications, including clear sky temperature, water vapor and aerosol retrievals as well as some cloud properties.”

Prerequisites and Concurrent Courses:

Mathematics through differential equations is a necessity for this course; a basic understanding of atmospheric thermal physics and classical electromagnetic theory is helpful.

Students who do not meet these prerequisites may be disenrolled according to Administrative Policy C-5 if they do not have the proper prerequisite override. Students who add the course after being disenrolled according to this policy are in violation of Item 15 on the Student Code of Conduct: https://studentaffairs.psu.edu/support-safety-conduct/student-conduct/code-conduct.

Required Textbooks and Recommended Textbooks: The course closely follows the content in

Fundamentals of Atmospheric Radiation by Craig Bohren and Eugene Clothiaux and
Conceptual Approach to Atmospheric Radiation edited by Eugene Clothiaux

as it is hard to ignore the ideas that one has written about in a textbook.

Assistance with Textbooks:

This course does not require that students buy any textbooks for it. The two recommended readings above will be provided with no fee to all students. That said, Penn State honors and values the socioeconomic diversity of our students. If you require assistance with the costs of textbooks for this course, contact the Office of Student Care and Advocacy (120 Boucke Building, 863-4926, http://studentaffairs.psu.edu/studentcare). For additional need related to socioeconomic status please visit http://sites.psu.edu/projectcahir.

Additional Materials but not on reserve (EMS Library in the Deike Building):

C.F. Bohren Clouds in a Glass of Beer
C.F. Bohren What Light Through Yonder Window Breaks?
R.M. Goody and Y.L. Yung Atmospheric Radiation (2^nd Edition)
K.N. Liou An Introduction to Atmospheric Radiation (2^nd Edition)
G.W. Petty A First Course in Atmospheric Radiation (2^nd Edition)
M.L. Salby Physics of the Atmosphere and Climate (2nd Edition)
G.L. Stephens Remote Sensing of the Lower Atmosphere
G.E. Thomas and K. Stamnes Radiative Transfer in the Atmosphere and Ocean
J.M. Wallace and P.V. Hobbs Atmospheric Science: An Introductory Survey (2^nd Edition)
J.A. Coakley and P. Yang Atmospheric Radiation: A Primer with Illustrative Solutions
Wendisch and P. Yang Theory of Atmospheric Radiative Transfer

Internet Materials and Links: None

Course Objectives/Outcomes: Students will understand and be able to apply concepts in atmospheric radiation.

Course Expectations:

All students will come to class prepared to discuss the course material at hand. Students are allowed to work on homework problems together. But, students must write-up their homework solutions on their own and have complete mastery of what it is that they have written. Students must meet the deadlines for the homework assignments. Habitual tardiness in turning in the homework will lead to a loss of points but only after a warning from the Instructor. However, students have the prerogative to contact the course instructor to ask for alternative deadlines. The instructor will be flexible this semester in meeting student needs, as long as students articulate in advance their needs to the Instructor.

Course Attendance:

Regular attendance is critical for building on the skills and knowledge developed throughout the class. Students who participate have a more complete understanding of the material presented and are more likely to succeed in the class. This is true whether your attendance is face-to-face or remote. This course abides by the Penn State Attendance Policy E-11: http://undergrad.psu.edu/aappm/E-11-class-attendance.html, and Conflict Exam Policy 44-35: http://senate.psu.edu/policies-and-rules-for-undergraduate-students/44-00-examinations/#44-35. Please also see Illness Verification Policy: https://studentaffairs.psu.edu/health-wellness/medical-services/policies-patient-resources, and Religious Observance Policy: http://undergrad.psu.edu/aappm/R-4-religious-observances.html. Students who miss class for legitimate reasons will be given a reasonable opportunity to make up missed work, including exams and quizzes. In all cases (unless from a provable dire emergency), you should inform the Instructor in advance so that all can plan together alternative arrangements. In addition to illness, legitimate reasons for missing class include religious observance, military service, family emergencies, regularly scheduled university-approved curricular or extracurricular activities, and post-graduate, career-related interviews when there is no opportunity for students to re-schedule these opportunities (such as employment and graduate school final interviews). Students who encounter serious family, health, or personal situations that result in extended absences should contact the Office of the Assistant Vice President for Student Affairs (AVPSA) and Student Care and Advocacy for help: http://studentaffairs.psu.edu/studentcare. Whenever possible, students participating in University-approved activities should submit to the Instructor a Class Absence Form: http://undergrad.psu.edu/aappm/classabs.pdf, at least one week prior to the activity.

Course Sick Days Policy:

The bottom line is very simple: please never come to a class when running a fever and do take time off from Zoom if you really do not feel well! Contact the Instructor via email letting the Instructor know that you will miss class because of illness. When you are feeling better and return to class via Zoom, meet via Zoom with the Instructor in order to develop a plan of action for making up all missed assignments.

Grading and Examination Policy:

For a summary of General and Final Examination Policies 44-10 and 44-20 and alternative assessment practices, please see Examination Policy Summary: http://handbook.psu.edu/content/examinations and General and Final Exam Policies: http://senate.psu.edu/policies/44-00.html#44-10.

Homework Assignments:

Homework assignments must be completed according to course expectations listed above. Homework assignments will compose 25% of the final course grade.

Radiation/Remote Sensing Project:

Each student will work in a team to present their radiation and/or remote sensing project. A radiation and/or remote sensing project will consist of a 50-minute lecture on some relevant aspect of the electromagnetic radiation field. The project will count for 25% of the final course grade. Each project must be approved by the Instructor via a set of discussions over the first half of the semester.

Examination Policy:

There will be two non-final exams, each worth 25% (for a total of 50%) of the final course grade. There will be no final exam for the course. The non-final exams will be given at appropriate times during the semester at a time agreed upon by all.

Grading Policy:

There will be no grade curving and the grading scale is as follows: A: 92.50-100.00; A-:90.00-92.49; B+: 87.50-89.99; B: 82.50-87.49; B-:80.00-82.49; C+: 77.50-79.99: C: 70.00-77.49; D: 50.00-69.99; F: < 50.00. For the final course grade the Instructor may throw out poor exam questions, adjust the percentages that homework and exams count, and/or adjust the grading scale above. This will be done in the same way for all students and only in such a way as to help each student’s overall course grade. No student will receive a grade less than what is based on the percentages above.

Make-Up of Missed Homework and Exams:

Students must contact the Instructor ahead of time to set alternative deadlines/times for homework and exams. Only as the result of an emergency will late work be accepted and make-up exams given without having first spoken with the Instructor about it. The bottom line: talk to the Instructor ahead of time about deadline/time problems down the road!

Webcam Requirements

This course requires you to have a webcam for course exams. If this represents a problem for you, you must communicate with the Instructor within a day of the scheduling of the exam to work out a solution. Classes and assessments will be conducted using Zoom. Only Instructor lectures will be recorded. Please contact the Instructor if you are unable to comply with this policy or have any questions or concerns about it.

Academic Integrity Statement:

Students in this class are expected to write up their homework sets individually and to work the exams on their own. Class members may work on the homework sets in groups, but then each student must write up the answers separately. Students are not to copy homework or exam answers from another person's paper and present them as their own. Students who present other people's work as their own will receive at least a 0 on the assignment and may well receive an F or XF in the course depending upon the circumstances. Please see: Earth and Mineral Sciences Academic Integrity Policy: http://www.ems.psu.edu/undergraduate/academic-advising/forms-and-procedures/academic-integrity, which this course adopts. To learn more, see Penn State's "Plagiarism Tutorial for Students."

Course Copyright:

All course materials students receive or to which students have online access are protected by copyright laws. Students may use course materials and make copies for their own use as needed, but unauthorized distribution and/or uploading of materials without the instructor’s express permission is strictly prohibited. University Policy AD 40, the University Policy Recording of Classroom Activities and Note Taking Services addresses this issue. Students who engage in the unauthorized distribution of copyrighted materials may be held in violation of the University’s Code of Conduct, and/or liable under Federal and State laws. For example, uploading completed labs, homework, or other assignments to any study site constitutes a violation of this policy.

Accommodations for Students with Disabilities:

Penn State welcomes students with disabilities into the University's educational programs. Every Penn State campus has an office for students with disabilities. The Student Disability Resources (SDR) website provides contact information for every Penn State campus: (http://equity.psu.edu/student-disability-resources/disability-coordinator). For further information, please visit the Student Disability Resources website (http://equity.psu.edu/student-disability-resources).

In order to receive consideration for reasonable accommodations, you must contact the appropriate disability services office at the campus where you are officially enrolled, participate in an intake interview, and provide documentation: http://equity.psu.edu/student-disability-resources/applying-for-services. If the documentation supports your request for reasonable accommodations, your campus’s disability services office will provide you with an accommodation letter. Please share this letter with your instructors and discuss the accommodations with them as early in your courses as possible. You must follow this process for every semester that you request accommodations.

Reporting Bias-Motivated Incidents

Penn State takes great pride to foster a diverse and inclusive environment for students, faculty, and staff. Acts of intolerance, discrimination, or harassment due to age, ancestry, color, disability, gender, gender identity, national origin, race, religious belief, sexual orientation, or veteran status are not tolerated (https://guru.psu.edu/policies/ad29.html) and can be reported through Educational Equity via the Report Bias webpage.

Counseling and Psychological Services

Many students at Penn State face personal challenges or have psychological needs that may interfere with their academic progress, social development, or emotional wellbeing. The university offers a variety of confidential services to help you through difficult times, including individual and group counseling, crisis intervention, consultations, online chats, and mental health screenings. These services are provided by staff who welcome all students and embrace a philosophy respectful of clients’ cultural and religious backgrounds, and sensitive to differences in race, ability, gender identity and sexual orientation. Services include the following:

Counseling and Psychological Services at University Park (CAPS): 814-863-0395
Counseling and Psychological Services at Commonwealth Campuses
Penn State Crisis Line (24 hours/7 days/week): 877-229-6400
Crisis Text Line (24 hours/7 days/week): Text LIONS to 741741

Penn State E-mail Accounts

All official communications from Penn State are sent to students' Penn State e-mail accounts. Be sure to check your Penn State account regularly, or forward your Penn State e-mail (see https://pennstate.service-now.com/sp?id=kb_article_view&sys_kb_id=90160f4ddb9ed0949cde83aa1396199b) to your preferred e-mail account, so you don't miss any important information.

Deferred Grades

If you are prevented from completing this course within the prescribed amount of time for reasons that are beyond your control, it is possible to have the grade deferred with the concurrence of the instructor, following Penn State Deferred Grade Policy 48-40 (http://senate.psu.edu/policies-and-rules-for-undergraduate-students/47-00-48-00-and-49-00-grades/#48-40). To seek a deferred grade, you must submit a written request (by e-mail or U.S. post) to the instructor describing the reason(s) for the request. Non-emergency permission for filing a deferred grade must be requested before the beginning of the final examination period. It is up to the instructor to determine whether or not you will be permitted to receive a deferred grade. If permission is granted, you will work with the instructor to establish a communication plan and a clear schedule for completion. If, for any reason, the course work for the deferred grade is not complete by the assigned time, a grade of "F" will be automatically entered on your transcript.

Military Personnel

Veterans and currently serving military personnel and/or spouses with unique circumstances (e.g., upcoming deployments, drill/duty requirements, disabilities, VA appointments, etc.) are welcome and encouraged to communicate these, in advance if possible, to the instructor in the case that special arrangements need to be made.

Technical Requirements

One must have access to email, pencils and paper. From time to time one may need to make use of a computer to perform a calculation or to put together a presentation in some electronic format.

Netiquette

The term "Netiquette" refers to the etiquette guidelines for electronic communications, such as e-mail and bulletin board postings. Netiquette covers not only rules to maintain civility in discussions, but also special guidelines unique to the electronic nature of forum messages. Please review some general Netiquette guidelines that should be followed when communicating in this course.

Disruptive Behavior

Behavior that disrupts normal classroom activities will not be tolerated, in accordance with Items 9 and 14 in the Student Code of Conduct. This includes in-class use of cell phones for non-coursework related topics.

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 Penn State's Office of Sexual Misconduct and Prevention & Response website.

Additionally, I am required to make a report on any reasonable suspicion of child abuse in accordance with the Pennsylvania Child Protective Services Law.

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:

Course Content

What a Practicing Meteorologist Needs to Know

Radiation and Matter
- The Big Picture (Sources of Radiation)
- Repartitioning of Energy within Matter
- Quantized Internal Energy States of Matter
- Simple matter
  - Single lines with widths and strengths
- Simple matter under increasing pressures
- Changes in single line parameters
- Complex matter
  - Multiple and merged lines forming continuum emission across all wavelengths
  - Planck Function Radiation
- Probability of Energy States within Matter
  - The Planck Function
Integro-differential Form of the Radiative Transfer Equation
- Radiance (185-191)
  - Power (185-186)
  - Solid Angle (186-188)
  - Definition of Radiance
  - Invariance of (191-192)
- Irradiance (206-211)
  - Connection to Radiance
  - Definition of Irradiance
- Building the Radiative Transfer Equation
  - Attenuation/Extinction Term
    - Absorption and Scattering Coefficients (51-66, 60-66)
    - From Coefficients to the Attenuation Term
  - Emission Term (4-15)
    - Absorptivity and Emissivity [Kirchhoff's Law (14-15)]
    - Planck Function
      - Temperature Dependent
    - Emission Term
      - Planck Function and Absorptivity/Emissivity Dependent
  - Scattering Term
    - Scattering Phase Function (293-295)
Heating Rates (58-59, 212)
- From Radiances to Irradiances
- From Irradiances to Heating Rates
Multiple Scattering: Elementary (Section 5.2)
- Visualizing the Radiation Field
Some Nomenclature
- Optical Thickness (256)
- Mean Free Path (253-254)
- Single-scattering Albedo (254-257)
- Asymmetry Parameter (254-257)
- Brightness and Color Temperature (21)
- Wavenumbers (or Inverse Centimeters) (79)
Properties of Matter: A First Look
- Building One's Intuition: Simple Sorts of Calculations
Properties of Matter
- Overview of Particle Concentrations and Cross Sections (91-94)
- Wavelength Dependence of Molecular Scattering (Fig. 2.12)
- Wavelength Dependence of Molecular Absorption (Fig. 2.12)
- Wavelength Dependence of (Spherical) Particle Scattering (Fig. 3.9, Fig. 3.11)
- Wavelength Dependence of (Spherical) Particle Absorption (Fig. 3.9)
Multiple Scattering: The Full Monte (Chapter 6)
Digging Deeper into the Properties of Matter (The Why of Things)
To Cohere or Not to Cohere (or, Why Clouds are So Important to Climate)
Classical Electromagnetic Theory
- From Radiation as Energy Bundles to Radiation as Waves (129-134)
- Charges and Electric Fields
- Moving Charges and Magnetic Fields
- The Lorentz Force
- Maxwell's Equations (Yikes!)
- Response of Matter to Electric Fields
- Response of Matter to Magnetic Fields
- Four Consequences of Maxwell's Equations
  - Speed of Light
  - Plane Electromagnetic Wave Solutions in Infinite Media (129-134, 141-142, 158-165)
  - The Poynting Vector (Irradiance) (185-186)
  - Production of Radiation by Accelerated Charges
    - Dipoles
Why Matter Scatters and Absorbs Radiation the Way It Does
- Scattering and Absorbing Properties of Molecules
  - Scattering by Air Molecules (128, 151-155)
  - Scattering Phase Function of Molecules
  - Absorption by Air Molecules (66-74, 76-84, 125-129)
    - Radiatively Active and Inactive Molecules (80-84)
    - State Populations and the Structure of Absorption (95-102)
    - Absorption Line Strengths, Shapes and Widths (102-105)
Scattering and Absorbing Properties of Particles
- Small Particles
- Large Particles
- Complex indices of refraction
- Scattering by Spherical Water Particles (165-175)
  - Coherence Effects (134-141, 146-148, 148-151)
  - Small and Large Particle Limits (168-169, 169, 170-172, 172-175)
- Absorption by Spherical Water Particles (110-115)
  - Small and Large Particle Limits
Radiation and/or Remote Sensing Project Presentations