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





Week 16: 7 December

Great Semester!

Final exam at normal class time on Monday, 7 December.
May bring note sheets, two 8.5" x 11" sheets, with equations and other notes on them.

Class evaluation link is here (please do so :)

Practice Final Exam here.

Useful and Related Information

Compared with the beginning of the semester, it looks like the warm water anomaly at the equator has strengthened,
while the blob is diminished greatly. Stay tuned for an interesting winter.

Week 15: 30 November

Class evaluation link is here (please do so :)

Practice Final Exam here.

Friday:
Ice cloud nucleation. Discussion of final exam. Presentation.

Wednesday:
Extensive discussion of Köhler curves and formation of cloud droplets form dissolved salts.
Also discussed the aerosol indirect effect, and general processes for precipitation formation in warm and cold clouds.

Monday:
Dissolvable aerosol as cloud condensation nuclei. Warm cloud microphysics. Presentation.

UNR weather station data for the last 7 days.

Useful and Related Information

Be present in your surroundings: Atmospheric Physics is everywhere! Go out and enjoy! Click images for larger version.

 


Presentation on surface tension and pressure inside a droplet.

Kohler curve presentations that may be helpful:
Presentation 1
Presentation 2
Presentation 3
Presentation 4
Presentation 5

Warm and cold cloud precipitation mechanisms. From here.

Ice multiplication in mixed phased clouds. Enormous numbers of ice crystals are observed
even though only small numbers of ice nuclei are present.
Hobbs 1969 paper; a 2014 paper on lab experiments with high numbers of ice crystals for scant reasons.

Recent paper on ice nuclei behavior of volcanic ash and the connection to mineral crystal lattice.

Week 14: 23 November

Wednesday: Demonstrations, measured the pressure as a balloon is blown up to illustrate the effect of
surface tension energy; used adiabatic expansion to create a cloud in a bottle, calculated the final temperature
from the pressure change, added smoke the second time to act as cloud condensation nuclei, and then added
rubbing alcohol to produce a much more optically thick cloud due ot the higher vapor pressure. The final demonstration
was made with a freezer, created a super cooled water droplet cloud inside of it first and then nucleated it for ice crystal
formation by adiabatic expansion from a toy pop gun. Afterwards talked about several homework problems.

Monday and Wednesday: Read chapter 6. Our topic of cloud and aerosol physics continues. Presentation.

Some of the Monday subjects: (click image for larger version)

 

Final exam will be Monday 7 December 2015.

Useful and Related Information

Salty solutions (from http://www.chem.wisc.edu/deptfiles/genchem/sstutorial/Text7/Tx75/tx75.html)

Research experience for undergrads: (Don't be shy, apply!)

Here's the general list: REU opportunities are at https://www.nsf.gov/crssprgm/reu/list_result.jsp?unitid=10020

Week 13: 16 November

Wednesday and Friday: Read chapter 6. Next topic is cloud and aerosol physics. Presentation.

Homework 7 due on Monday.
We will discuss radiation on Monday, likely wrapping up chapter 4. Presentation.

Some of the aerosol topics on Wednesday:

 

Useful and Related Information

Seminar On GPS and Applications, including Atmospheric Science
Friday, November 20th, from 4:00pm - 5:00pm in the Department of Physics Goudsmit conference room, LP 208.  
“The Revolution in Geodesy and Applications in Science using GPS.”

Nice presentations on cloud physics: first, second, third (backup of first).

UNR Weather Station: Graph of the last 7 days. Check out the solar radiation amount.

My research.

Solar noon view during the equinox. Sun angle and seasons.

Week 12: 9 November

Everyone, work on the homework. Bring questions to class on Friday. It's a way to get help on the HW, and
if you have questions, I'm sure others have questions too. Due date has been moved to Monday.
Our goal is to get it, and to get a lot out of it.

Monday Class: Review of Earth/Sun properties and solar zenith angle;
Discussion of radiance and irradiance; formal derivation of atmosphere heating rate and how radiation couples into atmospheric thermodynamics;
started the problem of calculating the direct and diffuse radiation coming through a cloud.

READ CHAPTER 4, Atmospheric radiation. Presentation. Homework 7 problems are given here.

Useful and Related Information

UNDERGRAD OPPORTUNITIES IN ATMOSPHERIC SCIENCES
NSF Sponsored Research Experiences for Undergraduate Students (great program!)
American Meteorological Society Undergraduate Scholarship Program (for Underrepresented groups)

Multiple scattering of light described in a very conceptual way with minimal mathematics by Craig Bohren [one of the best papers ever written].

Properties of the Earth.

From here.


 

Sun angle at different times of the year for 40 degrees north latitude, similiar to Reno at 39.5 degrees. From here.

Infrared radiation calculator.

Solar and infrared radiation at the UNR weather station.

Radiation calculator/simulator from Spectralcalc.

Mie theory calculator (scattering and absorption by spherical particles.)

Venus Fact Sheet

SOLAR PHYSICS Live data on the sun at a multitude of wavelengths.

Problem 4.42, can use to simulate retrieval of aerosol optical depth from satellite.
Analysis, calculations.

Week 11: 2 November

Monday Class: Radar, back scattering by hydrometeors, precipitation rate.

 

Midterm Exam Corrections

READ CHAPTER 4, Atmospheric radiation is next. Presentation.
Bring your questions for homework 6 to class on Monday. Here are the questions.

Discussion for Monday:
A) How many 20 micron cloud droplets are needed to have the same radar cross section
as a single 200 micron drizzle drop? [heavy tail size distribution problem]
B) What is the ratio of visible wavelength range scattering optical depth of the cloud droplets
compared to the drizzle drop?

Reminder: Groups should send me their presentations from the last homework assignment.

Useful and Related Information

Fortran code for light scattering calculations. Calculations below made with S7.for (Mie theory for spheres), images with gnuplot.

Internal Fields for spheres with radiation incident from the left. lossless, nr=1.5

size parameter 0.885

size parameter 8.85

E field parallel to plane
E field perpendicular to plane

 

Infrared radiation calculator.

Solar and infrared radiation at the UNR weather station.

Radiation calculator/simulator from Spectralcalc.

Mie theory calculator (scattering and absorption by spherical particles.)

Venus Fact Sheet

SOLAR PHYSICS Live data on the sun at a multitude of wavelengths.

Problem 4.42, can use to simulate retrieval of aerosol optical depth from satellite.
Analysis, calculations.

From the US National Weather Service Hanford California.

Week 10: 26 October

READ CHAPTER 4, Atmospheric radiation is next. Presentation.

Reminder: Groups should send me their presentations from the last homework assignment.

We will discuss the homework some on Wednesday.

Useful and Related Information

Demonstration and discussion of infrared radiation.

Infrared radiation calculator.

Solar and infrared radiation at the UNR weather station.

Radiation calculator/simulator from Spectralcalc.

Mie theory calculator (scattering and absorption by spherical particles.)

Venus Fact Sheet

SOLAR PHYSICS Live data on the sun at a multitude of wavelengths.

Problem 4.42, can use to simulate retrieval of aerosol optical depth from satellite.
Analysis, calculations.

Week 9: 19 October

Friday:

READ CHAPTER 4, Atmospheric radiation is next. Presentation.

Demonstration and discussion of infrared radiation.

Infrared radiation calculator.

Solar and infrared radiation at the UNR weather station.

Radiation calculator/simulator from Spectralcalc.

Mie theory calculator (scattering and absorption by spherical particles.)

Venus Fact Sheet

We are continuing with Atmospheric Thermodynamics, Chapter 3.
Presentation.

Groups have been assigned homework (mini projects) and we will present them (final presentation on Monday).

Let me know if we need to meet, or send me email if your group has questions.

Midterm exam on Wednesday. You may use an 8 1/2" x 11" paper with equations and notes (one side only) for the exam.

Practice midterm exam.

Start chapter 4, atmospheric radiation, on Friday.

Useful and Related Information

Student position in climate research open at UNR, click here for details.

Grad student talk on Thursday afternoon. Click on image for more details.

Upcoming seminar on El Niño. Click on image for details.

Week 8: 12 October

We are continuing with Atmospheric Thermodynamics, Chapter 3.
Presentation.

Groups have been assigned homework (mini projects) and we will present them.

Let me know if we need to meet, or send me email if your group has questions.

Useful and Related Information

Upcoming seminar on El Niño. Click on image for details.

CAPE calculation (note: must derive Eq. 1. See how it is exactly the hot air balloon problem).
Equation 3.71 of W&H can be used to calculate moist adiabats needed for CAPE.

ThetaE approximation and calculation.

Online book about meteorology.

 

Upcoming weather from the Hanford CA NWS office.

 

Week 7: 5 October

We are continuing with Atmospheric Thermodynamics, Chapter 3.
Presentation.

Groups have been assigned homework (mini projects) and we will work some on them.

Bring questions about your mini project to class.

If you have a laptop, you can bring it to go through how to get your data if it's not clear.

Practice midterm exam.

Useful and Related Information

Recycling of ice nuclei in the Arctic, relevant to our discussion on Monday.
Click on image, or here, for the full manuscript.

 

Figure 1, Remotely sensed cloud microphysics in the Arctic, and sounding, Figure 2, from this article.
Click on images for larger versions.

Related Barrow Alaska soundings for interpretation and thought.


 

Week 6: 28 September

We are continuing with Atmospheric Thermodynamics, Chapter 3.
Presentation.

Monday
We will discuss and use the skew T Log P thermodynamic charts of the atmosphere .
Water vapor notes from Friday. Click on image for larger version.

To do in class: attendance mandatory, in class homework.
Grades on webcampus for this assignment will change as you finish problems.

0. This problem was given in class. See the first board (click on it for larger version).
The second board describes how to work with the equivalent potential temperature.

1. Winter time dryness inside when it's cold outside.
Let Toutside=Tdew=-10 C, and Tinside=25 C.

a. Find the mixing ratio. (dashed line through Tdew)

b. Find the relative humidity inside. RH=100 * mixing ratio / saturation mixing ratio at inside temperature.

2. Measure the temperature and wet bulb temperature (Twb) in the classroom.
Find:
a. Lifting condensation level.
b. Tdew.
c. Theta. (dry adiabat through T to 1000 mb, and read temperature).
d. ThetaE (moist adiabat through LCL to TOA and back to 1000 mb along dry adiabat, read temperature).
click image for larger image.

3. Chinook winds, ascend Sierras from the west; precipitation; descend eastern side; find temperature.
SHOW THE TRAJECTORY ON THE PAPER VERSION OF THE SKEW T AVAILABLE IN CLASS. (This is what you'll turn in.)
FIRST WORK IT OUT USING THE LAMINATED SHEETS.

Taken from example 3.10.
Start at 950 mb, 14 C, 8 g/kg.
Ascend to 700 hPA. Let 70% of precip fall out, 30% remain with air parcel.
Descend to 950 mb and find the temperature and wet bulb potential temperature; compare with initial values.

Should find:
Initially wsat(T)=10.6 g/kg; Show that LCL=890 mb; ThetaW=14 C. Continue to 700 mb and should find Wsat=4.7 g/kg.
Amount of condensed water at 700 mb = 8 g/kg - 4.7 g/kg = 3.3 g/kg.
30% of 3.3 g/kg = 1 g/kg.
Parcel descends on moist adiabat until reaching a mixing ratio of 5.7 g/kg (at 760 mb), and then dry adiabat to 950 mb.
Final temperature is 20 C, mixing ratio is 5.7 g/kg.
Final wet bulb potential temperature is 14 C.

Note: 'Chinook wind' in this example results in T = 20 C, 6 C warmer than the beginning temperature,
with the extra heat due to the latent heat release during ascent, and that most of the condensation falls out.

Click on image for larger version.

Wednesday
We will work on the skew T assignment from Monday.
New homework assignment will be given.

Friday
Groups to discuss homework, in addition to thermo discussion in class.

Useful and Related Information

Skew T log P diagram from textbook, and as a gif file. Skew T presentation for in class discussions.
Interpretation of skew T indices.
Black and white version
of the Skew T graph.
Comet Program Meteorological Education on Skew T log P.

Potential temperature and equivalent potential temperature discussion.
Equivalent potential temperature map.

Cellular and wave structure in clouds on Monday afternoon at about 5:15 pm.

Week 5: 21 September

We are continuing with Atmospheric Thermodynamics, Chapter 3.
Presentation.

Monday
Discuss the chapter further. Groups prepare for presentations on Wednesday.

Wednesday
Discuss chapter; groups present homework problems.

Friday
Homework 3 due, and continue to discuss atmospheric thermodynamics.

Useful and Related Information

El Niño discussion.

Three month outlook for US weather.

And now ... the cold blob!


Week 4: 14 September

We are continuing with Atmospheric Thermodynamics, Chapter 3.
Presentation.

Monday
The remaining four groups will present their problems.
Problems 3.18 and 3.19.
Brief quiz.

Wednesday
Homework 2 due. Homework.
Continue with atmospheric thermodynamics.

Friday
Continue with atmospheric thermodynamics.

Useful and Related Information

Fine particle mass concentration in Reno, from fires in Northern California.
Click on images for larger version.
You can view the current conditions here.

Upper air charts discussion

Another discussion of upper air charts

5 uses of layer thickness

Undergraduate research scholarship program available: Deadline Oct 9th.

El Niño discussion.

Three month outlook for US weather.

Week 3: 7 September

Wednesday and Friday
Read chapter 3. We will have some discussion of concepts, and time for groups to work on homework problems.
Presentation.
Problems 3.18 and 3.19.

Homework.


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.

Useful and Related Information

Atmospheric thermodynamics from another perspective.

Ideal gas law demonstration tool.

Career Day Preparation: Click on image for larger version.

Summary of water vapor in the atmosphere.

Week 2: 31 August

Monday
We will discuss some of the homework problems (pg1, pg2) in class.
Problem 1.18 introduces water vapor path and precipitable water ideas.
Look at soundings from the Univ. of Wyoming site; look at indices.
Look for places and times in the world for low and high precip water to gain familiarity with the ideas.

Homework. Homework style guide.

Where we are headed:
We will go to Chapter 3 next, Atmospheric Thermodynamics.
Presentation.

Begin reading chapter 3, Atmospheric Thermodynamics.
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.

Useful and Related Information

Atmospheric thermodynamics from another perspective.

Ideal gas law demonstration tool.

Week 1: 24 August

Dr. Chris Moore of the Desert Research Institute will teach week 1 as I am visiting UNAM.

Introductions -- each student introduce themselves and give their major.

Syllabus.

Homework. Homework style guide.

Overview Presentation: Atmospheric Science relies heavily on measurements and models!

Origin of Atmosphere and Composition presentation, Wednesday's class.

Friday's class.
Arctic atmospheric chemistry science:
1. Research paper on atmospheric chemistry and sea ice relationship.
2. Presentation on research in the arctic.

Useful and Related Information:

World record hail stone in Vivian South Dakota. See more on hail.

The Earth's atmosphere is very dynamic (movie 5 fps and 30 fps).

Vertical structure of the atmosphere.

Wave cloud on the windy day, Friday August 14th. Click on image for larger version.

.

Godzilla meets the Blob! Sea surface temperature anomaly.

It will be interesting to see what happens this fall, winter, and spring season.
Godzilla - El Niņo - the relatively hot water near the equator off the coast of Peru
that is associated with extreme precipitation in the southwest US.
(Godzilla is a movie creation from 60's horror films). Source ABC news.

The Blob! The relatively warm water off the coast of CA, OR, and WA,
associated with the extremely persistent high pressure region
that brought extremely dry and warm conditions to these states in the last few winters.