EPS 290, Cloud Microphysics, Fall 2011

Overview

This course covers the processes that lead to the formation of cloud drops, ice particles, and rain. This "microphysics" influences the effect of clouds on Earth's radiation budget, determines whether or not a cloud precipitates, affects how strong a downpour can be, figures into our interpretation of radar maps, helps us interpret isotopic records of paleoclimate, and has been suggested as a lever with which to geoengineer our climate.

Time

Tuesdays at 2:00

Location

401 McCone Hall

Text

Rogers and Yau (a good purchase, but assigned excerpts will be distributed)

Seminar format

We will use Rogers and Yau (A Short Course in Cloud Physics) as the main text. There will be a weekly reading assignment (usually just one of the chapters, which are short) and we will discuss the chapter at the weekly meeting. The discussion will be led by a volunteer who will walk us through the chapter. This will be our opportunity to solidify what we read, put it in context, and ask questions (of each other, not necessarily of the volunteer). The volunteer will have one more duty, and that will be to briefly describe a supplemental reading, which will inject some relevant current research into the discussion. To keep the workload manageable, only that week's volunteer must read the supplemental paper . Finally, the syllabus below is tentative: feedback is encouraged, and adjustments can be made to suit participants' interests.

Syllabus

8/30, Organizational meeting

• Confirm meeting place and time
• Overview of seminar format
• Pick next week's discussion leader

9/6, Refresher on moist thermodynamics -- led by Nadir Jeevanjee

• Reading: Rogers and Yau, Chapters 1 and 2
• Supplement: Zipser (2003) -- What about the latent heat of fusion?

9/13, Parcel model of convection -- led by Kyle Pressel

• Reading: Rogers and Yau, Chapter 3 (pages 28-35) and chapter 4
• Supplement: Paluch (1979) -- What is the evidence for cloud-top mixing?

9/20, In-situ observations -- led by Edwin Kite

• Reading: Rogers and Yau, Chapter 5
• Supplement: Gerber (2008) -- New insights from 1000-Hz measurements
• Supplement: Section 3.1-3.3 of Baumgardner (2011) -- Overview of in situ cloud measurements

9/27, Liquid drop nucleation -- led by Daniele Rosa

• Reading: Rogers and Yau, Chapter 6
• Supplement: Grabowski, Andrejczuk, and Wang (2011) -- How is activation treated in research models?

10/4, Condensational growth -- led by Jesse Day

• Reading: Rogers and Yau, Chapter 7 (pages 99-112)
• Supplement: Rogers and Yau, Chapter 7 (pages 112-119) -- What is missing from that simple theory?

10/11, Collision-coalescence: continuum theory -- led by Kyongmin Yeo

• Reading: Rogers and Yau, Chapter 8 (pages 121-134)
• Supplement: Andrejczuk (2009) -- What controls homogeneous versus inhomogeneous mixing?

10/18, Collision-coalescence: statistical theory -- led by Lindsey Nolan

• Reading: Rogers and Yau, Chapter 8 (pages 134-148)
• Supplement: Shaw et al (1998) -- How does turbulence enhance spectral broadening?

10/25, Ice crystals -- led by David Romps

• Reading: Rogers and Yau, Chapter 9
• Supplement: Cantrell (2005) -- 20 years later, what questions remain?

11/1, Lightning -- led by Jennifer Frederick

• Reading: MacGorman and Rust, Chapters 1 and 3
• Supplement: None; this is a long reading.

11/8, Rain and snow -- led by Percy Link

• Reading: Rogers and Yau, Chapter 10
• Reading: Montero et al (2009) -- How fast do raindrops fall, really?

11/15, Radar -- led by Daniel Feldman

• Reading: Rogers and Yau, Chapter 11
• Supplement: Vivekanandan (1999) -- What can dual polarization tell us?

11/22, Microphysics of isotopologues

• Reading: Clark and Fritz, Chapter 2 (http://www.science.uottawa.ca/eih/ch2/ch2.htm)
• Supplement: Bradley, section 5.2 (tentative)

11/29, Geongineering through microphysics -- led by Lara Gunn

• Reading: Heymsfield (2011) -- inadvertent
• Supplement: Rasch (2009) -- intentional

12/6, No class -- AGU