### ATMS 411 Atmospheric Physics [main page] [homework] [2015 notes][2010 notes].

Week 16: 11 December

Read chapter 5 section 5.4, pg 169-176 on atmospheric aerosols.

Read chapter 6, concentrating on the ideas of cloud physics.

We will discuss in class the main ideas of cloud physics, and the essential role played by atmospheric aerosol.

Chapter 5 and 6 presentation. Start reading on chapter 6. We will discuss parts of chapter 5 to help with chapter 6. Cloud microphysics

Final Exam Wednesday December 20th from 7:30 am to 9:30 am.
You can bring an equation sheet, 8.5" x 11" with notes on front and back. Bring your calculator.

IN CLASS PORTION ON THE 20th: Comprehensive, chapters 1, 3, and 4. Review homework and mid term exam, and topics of these chapters. (75%)

TAKE HOME PORTION DUE THROUGH WEB CAMPUS ON 20 DECEMBER 2017: (25%)
Ideas in the reading for chapter 5 and chapter 6. Questions for review from chapter 6.
Problems 6.8 a, c, e, f, j, o, u, bb, ee, and gg. These are short answer questions as we've been doing all semester.

Practice final exam.

More Skew T practice: Problems 3.37, 3.45, 3.47, 3.48, 3.53, Solutions to check your work are here. The skew T as a gif file is here.
More practice problems with solutions are here. Skew T tutorial is here.

Week 15: 4 December

Read chapter 5 section 5.4, pg 169-176 on atmospheric aerosols.

Read chapter 6, concentrating on the ideas of cloud physics.

We will discuss in class the main ideas of cloud physics, and the essential role played by atmospheric aerosol.

Chapter 5 and 6 presentation. Start reading on chapter 6. We will discuss parts of chapter 5 to help with chapter 6. Cloud microphysics

Monday: Marcela Loria discussed homogeneous nucleation of cloud droplets during my absence.

Wednesday: Discussion of surface tension and surface tension energy. Demonstrations of cloud droplet growth analogy using bubbles and balloons.

Friday: Demonstration of cloud formation by adiabatic expansion: Aiken counter basics.

Related Information

Now that we are in winter, review the reason for the season.

Clouds observed near Dallas (left) and New Orleans (right) on 6 December 2017. Click images for larger versions.

Week 14: 27 November

Bring questions to class about the homework - we'll discuss homework problem hints, Monday and Wednesday. We will look at more topics in Radiation Transfer.

Earth's orbit -- in relation to problems 4.21 and 4.29.

Chapter 4 presentation. Will discuss radiation topics on Monday.

Chapter 5 and 6 presentation. Start reading on chapter 6. We will discuss parts of chapter 5 to help with chapter 6. Cloud microphysics.

Wednesday's class notes. Further discussion of problems 4.21 and 4.29. Click images for larger version.

Monday's class notes. Discussion of the homework problems. Click images for larger version.

Week 13: 20 November

Monday and Wednesday: Finish theory for transmission of sunlight through clouds, and cloud albedo. This is the set up for the next homework assignment. We will use the Mie Theory calculator.
An excellent paper on multiple scattering, Craig F. Bohren.
Multiple scattering of light and some of its observable consequences.
American Journal of Physics, 55(6):524--533, June 1987.

Homework 5 was posted: begin working on it.

Images from Monday's class. Click images for larger versions.

Images from Wednesday's class. Albedo of clouds above the ground having albedo A. (Effect of ground on cloud albedo).
Click images for larger versions.

Week 12: 13 November

Friday: Theory for transmission of sunlight through clouds, and cloud albedo. This is the set up for the next homework assignment. We will use the Mie Theory calculator.

Note that there is a climate talk at 4 pm on Friday. Climate Variability and The Global Hydrologic Cycle: Efforts in Monitoring, Modeling and Challenges in Forecast Changes

We took a field trip outside to look at the sky (why is it blue, and polarized for visible wavelengths? And why are clouds white/grey?), and looked also at the IR.
Then we started the theory of multiple scattering for short wave spectra.

Wednesday: Finished presentations on homework assignment 4.

Discussed size parameter and radiation penetration depth.

Notes: Click images for larger version.

Monday: Presentations by students/groups on homework assignment 4.

Chapter 4 presentation. We will return to the discussion of interaction of light with atmospheric objects.

Notes on particle optics from Wednesday, 8 November 2017 class. Click images for larger versions.

Related Information

Paper on the history of blue sky theories.

An excellent paper on multiple scattering, Craig F. Bohren.
Multiple scattering of light and some of its observable consequences.
American Journal of Physics, 55(6):524--533, June 1987.

 Field work and forward scattering by aerosol, Tecamac University near Mexico City, 2006. Click image for larger version.

 Cloud optical depth from this reference. Click image for larger version. Related paper on cloud radiative properties. Complex refractive index of ice as a function of wavelength from this reference. Click image for larger version.

Week 11: 6 November

Wednesday:
Structure of water vapor, liquid water, and water ice.
Second water vapor discussion, with animation of normal modes.

"Mie theory" calculator for homogeneous spherical particles described by a complex refractive index.

Monday: Turn in revised mid term exam at beginning of class.
We will:
Review Venus temperature structure from the Chapter 4 presentation.
View water vapor and visible wavelength satellite imagery.

Work from absorption of radiation by a single molecule to the planetary radiation budget for gaseous atmospheres.
Here's the absorption spectra of the Earth's main infrared active (green house) gases, H20, CO2, CH4, and O3.
1 layer atmosphere model summary.
Spreadsheet to work with the 1 layer model.
Notes for the 1 layer model set up.
Monday's notes: Click image for larger version.

Related Information

College of Science talk on the International Space Station

An excellent paper on multiple scattering, Craig F. Bohren.
Multiple scattering of light and some of its observable consequences.
American Journal of Physics, 55(6):524--533, June 1987.

Week 10: 30 October

Be sure your presentation for homework 3 has been turned in through web campus.

The midterm exam is on Monday October 30th.
Here are two previous exams to use for study. Exam 1. Exam 2.
You can use an equation/note sheet, one side, 8 1/2" by 11", for the exam.

Take home part of the exam for those that want to improve their grade:
The exam will be handed back on Wednesday, November 1st.
Take the exam home. Treat the exam as a new homework assignment.
Solve all problems on a separate sheet of paper (or papers).
Up to 50% credit can be regained by redoing the exam.
For example, if you got 60%, you can move your grade up to 80% by turning in a 100% correct revision.
Revisions are due in class on Monday before class, November 6th.
For those who have a grade in excess of 90%, no need to do a revision.
I'm available during office hours from 1 to 3 on Wednesday to discuss problems.

Wednesday and Friday Class
Presentation for chapter 4.
Homework 4 has been posted. It is a group effort, conceptual problems from chapter 4.
Presentations on Homework 4 will begin on Friday November 8th.
Online homework 4 has been posted, and is due Sunday November 5th.

Week 9: 23 October

The midterm exam is coming up on Monday October 30th.
Here are two previous exams to use for study. Exam 1. Exam 2.
You can use an equation/note sheet, one side, 8 1/2" by 11", for the exam.

Wednesday Class
Develop stability point by point for the dry atmosphere.
Look at conditional instability.
Look at convective instabilty.
Look again at air motion over a mountain range.
Discuss sound propagation in the atmosphere and the influence of temperature structure on it.

Monday Class

First, let's look for clouds and gravity waves using NASA Worldview satellite imagery.
Look at the month of April 2017.
Look also at the fluid motions near Guadalupe Island off the coast of Baja CA, example May 18th 2008. (ship tracks and atmospheric glory also are visible).
Also look at the month of October 2017, including N. CA, transition from the 8th to the 9th.

Then let's look at the theory for gravity waves.
Monday: Gravity waves, Brunt Vaisalla frequency, see Presentation for chapter 3 near the end.
The frequency of gravity waves in the atmosphere is determined by atmospheric stability.

Related Information

Gravity waves in mountain areas.

Discussion of difference between gravity waves in geophysics and gravitional waves due to distortion of space/time.

Week 8: 16 October

Homework 3 presentations begin on Monday.

Presentation for chapter 3.

Related Information

Discussion of atmospheric stability in general, to supplement the textbook discussion.

Another discussion of stability, and another.

The midterm exam is coming up. Here are two previous exams to use for study. Exam 1. Exam 2.

Here is the example sounding Excel spreadsheet we've been working on.
Here are calculations of the lapse rate, and graph of the potential and equivalent potential temperature for comparison. Click images for larger versions.
You have to do the graph on the right for your presentation, but not the one on the left.

Week 7: 9 October

Here is the spreadsheet we worked on during Monday's class.

Continue with Chapter 3, working with homework 3.
We will continue working with the this example spread sheet for calculating CAPE and precipitable water for your sounding.
Work very hard with your group to get this assignment done this week.
Presentations on this assignment start on Monday the 16th of October.
Reports are due after the presentations.

Presentation for chapter 3.

Related Information

The midterm exam is coming up. Here are two previous exams to use for study. Exam 1. Exam 2.

Week 6: 2 October

Continue with Chapter 3, especially skewT logP diagrams, water vapor, and begin homework assignment 3.
Be sure to come to class. Use of the skewT diagrams for the atmosphere is much easier to understand that way.
Example: Measure the temperature and wet bulb temperature in the classroom. Then obtain the following:
1. Lifting condensation level.
2. Dew point temperature.
3. Relative humidity.
4. Potential temperature θ.
5. Wet bulb potential temperature θw.
6. Equivalent potential temperature θE.

Presentation for chapter 3.

Related Information

Skew T log P diagram as a gif file. Right click on the image and copy it. Paste it into 'Paint' to work with it.
Skew T presentation for in class discussions

Week 5: 25 September

Continue with Chapter 3, especially skewT logP diagrams, water vapor, and begin homework assignment 3.
Homework presentations for the assignment 2 will finish on Monday.

Presentation for chapter 3.

Related Information

Temperature and pressure in Barrow and Rochambeau for winter and summer. Click image for larger version.

Lenticular cloud and waves in clouds: applications of stability and atmospheric gravity waves. Click on image for larger version.

September 2017 temperature in Reno (from the NWS). Reno soundings for 2017.

Week 4: 18 September

Continue with Chapter 3. Homework presentations for the assignment 2 begin on Friday. Work with your group to prepare for this assignment.

Related Information

Hurricane tracks and sea surface temperatures. Click for larger image.

Week 3: 11 September

Homework 1 due on Monday.
Online homework assignment 2 has been posted.

Read chapter 3, Atmospheric Thermodynamics. We will have several homework assignments from this especially important chapter.
Presentation for chapter 3.

The goals (learning and review objectives)

a. Ideal gas equation applied to dry and moist air.
b. Virtual temperature.
c. Potential temperature.
d. Hydrostatic equation.
e. Increasingly detailed description of the temperature and pressure distribution in the atmosphere.
f. SkewT logP diagrams.
f-g. Relative humidity, absolute humidity.
g. Dew point temperature.
h. Wet bulb temperature.
i. Equivalent potential temperature.
j. Latent heat release and absorption in condensation and evaporation of water.
k. Stability of air parcels.
l. Indices on soundings.

Related Information

Geostrophic wind -- relation to constant pressure surfaces

Cumulative hurricane tracks from 1985-2005 from NASA.
Ocean surface temperature.

Week 2: 4 September

Additional office hours (RM 213 of Leifson Physics) are available from 1 pm to 3 pm Tuesday September 5th.

You are encouraged to work with others on the homework, reach out to fellow students if you are interested in doing so.

Homework 1 (meteorology case study) is due 11 Sept 2017. See http://www.patarnott.com/atms411/homework2017.htm.
Turn it in through web campus.

Here's our case study from week 1.

Meteorology of the world: Use Google Earth to view locations and clouds
Look at data for 12Z, 24 August 2017
Near equator: Rochambeau French Guiana (get sounding for SOCA from the Wyoming site, plot pressure vs height, calculate density and plot versus height)
Near north pole: Barrow Alaska (get sounding for PABR from the Wyoming site, plot pressure vs height, calculate density and plot versus height)
Then we will fit a trendline for ln(Pressure) vs height to obtain the scale height of the atmosphere at these two locations, considering data to a height of 10 km.
Then we will observe and discuss the lapse rate Γ=-dT/dz from the slope of the temperature versus height graph.

Related Information:

We are looking at two sites representative of Earth locations spanning the extremes from the equator to the poles.

Here's a look at the 500 nm height of the atmosphere for August 2017, slow animation, faster animation, to appreciate the dynamical nature of the atmosphere.
We will return to this topic in our study of chapter 3.

Hurricane scale.
Hurricane description part 1, part 2.
Tropical cyclone structure.

Week 1: 28 August

Online Homework 1 is due 3 Sept 2017. See webcampus.
Homework 1 (meteorology case study) is due 11 Sept 2017. See http://www.patarnott.com/atms411/homework2017.htm.
Both will be turned in through web campus.

Homework for Monday and Tuesday: Read chapter 1.
This class will be one part lecture;
one part active class participation/activity involving atmospheric data from around the world;
and one part study using online modules for atmospheric science education.

Introductions -- each student introduce themselves and give their major.
Homework. Homework style guide.
Weather and geophysical data and models.

Free online Introductory Textbook for Atmospheric Science and local backup.

Overview Presentation: Atmospheric Science relies heavily on measurements and models!
Origin of Atmosphere and Composition presentation chapter 2.
Vertical structure of the atmosphere.

Meteorology of the world: Use Google Earth to view locations and clouds
Look at data for 12Z, 24 August 2017
Near equator: Rochambeau French Guiana (get sounding for SOCA from the Wyoming site, plot pressure vs height, calculate density and plot versus height)
Near north pole: Barrow Alaska (get sounding for PABR from the Wyoming site, plot pressure vs height, calculate density and plot versus height)
Then we will fit a trendline for ln(Pressure) vs height to obtain the scale height of the atmosphere at these two locations, considering data to a height of 10 km.
Then we will observe and discuss the lapse rate Γ=-dT/dz from the slope of the temperature versus height graph.

Notes from class on Wednesday. Click on images for larger version.

Related Information:

Weather

The Earth's atmosphere is very dynamic (movie 5 fps).

.