Ice and Snow Physics

METEO 582: Ice and Snow Physics

Spring 2019

Instructors: Matthew R. Kumjian and Jerry Y. Harrington

Office: 513 Walker Building, 517 Walker Building

Phone: 814-863-1581, 814-863-1584


Office Hours: TBD

Class meeting times and locations: Monday 4 - 5:15pm, Thursday 3:30 - 4:45pm in 529 Walker Building

Prerequisites: General background in physics/atmospheric sciences, Mathematical proficiency through differential equations. Cloud Physics (METEO 533) recommended.

Course Description: The purpose of this course is to provide graduate students in the physical sciences with a venue to explore ideas on the physics of snow and ice. The topic for the semester is chosen in advance by the instructors, along with the list of subjects for the semester. However, modifications to the topics and order are not only possible, but are encouraged so long as any changes fit within the general structure and topic for the semester.

This semester, our focus will be on the surface physics of ice. We will focus on the following primary questions: What do we know about the incorporation of molecules into the ice surface as a function of temperature and supersaturation? What does this tell us about how ice grows, and how habits form and develop? What holes exist in our knowledge presently and what sorts of studies need to be done to fill in the gaps? How are these processes represented in existing numerical weather prediction models?

Course Organization: The course primarily will be a lecture and discussion course and will be organized as follows: the first 2-3 weeks of the course will consist of introductory lectures by the instructors. During this time, journal articles and book chapters related to the topics for the semester will be made available. After the 3rd week, students in the course will present on a given topic. This will consist of reading a primary paper, and satellite papers required for a rich understanding of the topic. Each student will present for 30 minutes, with the presentation serving as an introduction to the topic and as a basis for discussion. The student, with the help of the instructors, will then lead a discussion for one hour on the topic for the week.

In preparation for the discussion, all participants in the class (whether taking the course for a grade or not) will read the primary paper, and other papers/chapters as need be. Each student (even those auditing the course) will come to class prepared with questions on the topic/paper, possible answers, and a synopsis of the topic. The student’s synopsis, question(s), and possible answers will be brought to class as a typed, single sheet of paper. The sheet will be turned in at the end of the class period and counts towards the final grade as described above.

Note on the outline below: The first three days will be lectures given by the instructors. After that period of time, students will present papers associated with each bulleted topic. Unless otherwise stated, the first article in the list for a given bullet is the primary article for that topic (and that day's presentation). All students should read that particular paper thoroughly. Other papers in the list are primarily for the presenter, and provide extra information that may make the presentation richer. There are a few articles that are very short, and in those cases students should read all of the articles in the list. We have indicated the days on which you should read both articles. Happy reading!

Course Topics:

Background (Particle Growth Review, Basic Ideas, Week 1: Days 1 and 2): Harrington

  • Course Overview
  • Observed growth habits and their relation to the surface of ice
  • Basic growth models: Capacitance, Screw Dislocations, Step Nucleation
  • Relevant papers (in preliminaries folder): Jefferys (1918), McDonald (1963), Uwaha (2016), Lamb dissertation appendix (1970)

Observations of Ice Particles in Clouds (Week 2, Day 3): Kumjian

  • Ice particles and their origins, observed habits
  • Measured and calculated supersaturation that drive growth

Diffusion-Limited Growth: The Capacitance Model (Week 2, Day 4): Nick

  • Electrostatic Analogy with Ice and its failure ( Please read both articles. Westbrook et al., 2008, Bailey and Hallett, 2010)

Constant Deposition Coefficient (Small Crystals) [Week 3]

  • Single Particles (Magee et al., 2006) -- Paul
  • Particle Populations (Skrotzki et al., 2013) -- Sean

Faceted Growth: Growth by Steps

  • Dislocation Growth: Lamb and Scott (1974) [Week 4]
  • Dislocation Growth: Sie and Gonda (1989), Beckman et al. (1982) [Week 4]
  • 2-D Nucleation: Libbrecht (2003) [Week 5]
  • 2-D Nucleation: Nelson and Knight (1998) [Week 5] -- Rachel
  • Evidence of Steps: Sazaki et al. (2014) [Week 6] -- Elissa

Gas-Phase Volume Diffusion and Surface Steps

  • Basic Theory (Kuroda, 1984) [Week 6]
  • Measured growth of facets (Asakawa et al., 2014; Inomata et al., 2018) [Week 7]
  • Growth Mechanisms, Habit Forms, Lacunae (Nelson, 2001) [Week 7] -- Rachel
  • Pressure Dependent Growth (Gonda 1980, Beckmann et al. 1983) [Week 8]
  • Measurements of Quasi-Liquid Layers (Asakawa et al., 2015,2016) [Week 8] -- Sean
  • Dendritic Branching, Mullins-Sekerka Instability (Libbrecht, 2005, Ben-Jacob, 1983) [Week 9]
  • Dendritic Branching, Facet Instability (Nelson, 2005; Yamashita, 1976,) [Week 9]
  • Growth Transitions: Single and Polycrystals (Read both articles: Gonda and Yamazaki, 1983, Bacon et al., 2003) [Week 10] -- Elissa
  • Growth Transitions and Grain Boundaries (Pedersen et al., 2011, Furukawa and Kobayashi, 1978) [Week 10]
  • Formation of Cubic Ice During Growth (Thurmer and Nie, 2013) [Week 11] -- Rachel
  • Sublimating crystal and roughness (Nelson, 1998) [Week 11]
  • Mesoscopic roughness (Magee et al., 2014) [Week 12] -- Sean
  • Roughness on prism faces (Neshyba et al., 2013) [Week 12]

Growth Models & Parameterizations

  • Capacitance model and density evolution (Koenig, 1971) [Week 13]
  • Capacitance model and mass-size relations (Mitchell, 1988) [Week 13]
  • Adaptive Habit Parameterization (Chen and Lamb, 1994) [Week 14]
  • Limitations of capacitance/mass-size models (Westbrook and Heymsfield, 2011, Harrington et al., 2013) [Week 14] -- Elissa
  • Attachment Kinetics Parameterization (Zhang and Harrington, 2014) [Week 15]
  • Attachment Kinetics Parameterization and Measurements (Harrington et al., 2019) [Week 15] 

Assessment Policy: Student grades will be determined based on:

(1) The quality of the presentations given in class (25%);

(2) The quality of the weekly written questions and topic synopsis (25%);

(3) A final course paper (50%).

The final course paper will be the student’s perspective on the main course topic. In essence, the paper will be the student’s attempt to integrate the knowledge gained during the course into an overall picture of how ice crystals evolve from the vapor. The paper will be no less than 5 pages long, but no longer than 7 pages. (Figures and references are not included in the page totals.) The paper will be 11-pt font with 1.5-line spacing along with 1-inch margins. The paper should have a title, date, and page numbers. We expect the grammar and spelling to be free of errors written work. Final papers are due on the last day of classes by noon and may be submitted through Canvas. Final course papers are not required for those who are auditing the course, though writing such a paper is highly encouraged! 

- Please note that the sections below were authored by others in the University community and not by the faculty who are in charge of this course. -

Academic Integrity: This course follows Penn State's Academic Integrity Policy. Penn State defines academic integrity as "the pursuit of scholarly activity in an open, honest and responsible manner." Academic integrity includes "a commitment not to engage in or tolerate acts of falsification, misrepresentation, or deception." In particular, the University defines plagiarism as "the fabrication of information and citations; submitting other's work from professional journals, books, articles, and papers; submission of other student's papers, lab results or project reports and representing the work as one's own." Penalties for violations of academic integrity may include course failure. 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.

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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. 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.

Attendance Policy: Attendance and participation in this course is required!

This course abides by the Penn State Attendance Policy E-11, and Conflict Exam Policy 44-35. Please also see the Illness Verification Policy, and Religious Observance Policy. Students who miss class for legitimate reasons will be given a reasonable opportunity to make up missed work, including exams and quizzes. Students are not required to secure the signature of medical personnel in the case of illness or injury and should use their best judgment on whether they are well enough to attend class or not; the University Health Center will not provide medical verification for minor illnesses or injuries. Other 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. Whenever possible, students participating in University-approved activities should submit to the instructors a Class Absence Form at least one week prior to the activity.

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In addition, one of the instructors for this course is "Safer People/Safer Places" certified