Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

AT623 - Atmospheric Boundary Layer - Fall 2001

Fall 2001 Class enjoying the midterm!


Final: 11:20am-1:20pm on Friday. Dec 14th. We can delay
the exam time by a half hour or so if there is a conflict in traveling to
the Foothills after the Dynamics exam (and if you want to have lunch!).

Midterm was on: October 23rd

* I want, however, to alert you that a B or better is required to avoid completing all of the homework assignments and turning them in. If you do not achieve a B or better, your course grade will require the correct completion of the homework, as well as a B or better on the final and on your class project.


Class Assignment - Date: November 16, 2001

As we discussed in class, two problems are assigned for the Final as take-home:

  1. Use surface similarity theory to define deposition velocity as a
    function of Z/L, Z naught, and a mean pollution concentration at height z.
    Discuss what a deposition velocity is intended to represent, When would a
    deposition velocity approach fail? ( 2 pages or so)
  2. Discuss in two pages or so the controversy that Zhong and Doran, and
    Weaver and Avissar have on the importance of landscape heteorogeneities.
    What is your view on this issue?

These two problems are due at the Final Exam (although, of course, you can turn in earlier!).

The Final Exam is scheduled for 11:20am-1:20pm on Friday Dec 14th. We can delay the exam time by a half hour or so if there is a conflict in traveling to the Foothills after the Dynamics exam (and if you want to have lunch!).

Our next class is Tuesday Nov 27th. The 15 minute presentations will be given by Liz, Gustavo and Tim. Please turn in copies of your slides/transparencies as you complete your talks. The following presentations are Tuesday, Dec 4th by John, Russ C. and
Russ S. The final talks are on Friday Dec 6th by Chris and Jesse.

Class FYI - Date: November 13, 2001

We will finish the class lectures today. We do not need to meet on Thursday of this week. The class presentations begin on Nov 27th, where you show us what you have learned in terms of dissecting the PBL parameterizations, and highlighting their strengths and weaknesses. See you at 9am today.

Class Assignment - Date: November 6, 2001

I incorrectly selected the wrong paper by Chris Doran. The correct one is Zong and Doran, 1998: J of Climate. It is cited in the Weaver and Avissar BAMS paper. The Zhong and Weaver paper (and the earlier 1997 J of Climate one), will provide the framework which the BAMS paper discusses. Since we will not have class til Tuesday, I suggest you directly obtain the paper.

Class Assignment - Date: November 6, 2001

Just to remind you, there is no class on Thursday of this week. On Tuesday the 13th, we will discuss how to represent dispersion using the concepts we have introduced.


Below is are dates for your presentations:

Nov 27: Liz Z; Gustavo P; Tim N.

Dec 4: John S; Russ C.; Russ S.

Dec 6: Chris C.; Jesse R.

Anyone whose is taking the class for credit that I left off?


We have the following reserved presentations on the specified dates:

  1. Nov 27: Liz Zarovy; Gustavo Pereira
  2. Dec 4: John Strack; Russ Chibe: Russ Schmacher
  3. Dec 6: Chris Castro; Jesse Ryan


So far, we have the following reserved presentations on the specified dates:

  1. Nov 27: Liz Zarovy; Gustavo Pereira
  2. Dec 4: John Strack
  3. Dec 6: Chris Castro

(note there will be no class Nov 29th). With respect to what to hand in, I just need a copy of your viewgraphs and/or powerpoint slides. This is due the day of your presentation.

CLASS INFO- Date: October 16, 2001

Following is a summary of what was discussed today:

  1. The Midterm will be October 30th (details to be presented this Thursday).
  2. The Final Exam will be Finals week.
  3. The class presentations start on Nov 27th and continue on Dec 4 and 6.
  4. There is no class on Tuesday October 23rd.
  5. We do not need to meet anymore on Wednesdays. Thanks for being flexible in doing this!

See you Thursday; remember to bring your Rev in Geophys. paper that was handed out several weeks ago.

MIDTERM - Date Assigned: October 11, 2001

Let me have your votes for the date of the midterm. Keep asking questions regarding the text and the problems. For Tuesday's class, I want to have an open forum for questions on any topic we have covered.

Assignment 14 - Date Assigned: October 9, 2001

The problems assigned for Chapter 7 are 2-6, and 10 (for Fort Collins on Dec 21 and June 21), 14, 17, 18, and 21.

Assignment 13 - Date Assigned: October 3, 2001

Please read Chapter 7. The problems for Chapter 6 are 1, 2, 4-8, 11, 16-17, 22, 24, 28, and 31.

Remember, no class tomorrow.

MIDTERM PROBLEM - Date Assigned: October 3, 2001

I am formally assigning the following problem as part of your AT 623 Midterm. It is due at the beginning of class on the day of the Midterm.

Assume a lapse rate of 10 degree C per 10 meters and an ambient wind speed of zero, calculate the time required to obtain an adiabatic lapse rate across this depth using various estimates of mixing within a stable surface layer. The idea is that a wind turbine would perform this mixing, so, for example, if you apply K-theory, the turbulent exchange by the turbines would be represented by K. Repeat for a depth of 20 meters with this lapse rate.

Assume there is no lateral movement of the air, so the turbulent exchange only has an effect in the vertical. Access the literature to obtain actual estimates of the exchange rate associated with wind turbines as used for frost/freeze protection.

State your assumptions when you summarize your results. We can discuss in class if clarification is needed.

See you today at 12:10pm.

Assignment 12 - Date Assigned: October 2, 2001

For tomorrow's class at 12:10pm, please read Chapter 6. Problems will be assigned. There will be no class on Thursday. Today we will overview where we are in the description of the stable and unstable PBL.

Assignment 11 - Date Assigned: September 26, 2001

The readings assigned today were:

  1. Sharan et al 1996: Bhopal gas leak: A numerical investigation of the
    prevailing meteorological conditions. JAM
  2. Gopalakrishnan et al 1998: Study of radiative and turbulent processes
    in the stabel boundary layer under weak wind conditions. JAS
  3. Chapter 8 selected pages in Pielke Nesoscale Meteorogical Modeling.

Assigned Readings - September 26, 2001

  • McNider et al, 1988: Influence of diurnal and inertial boundary-layer
    oscillations on Long Range Dispersion. Atmos Envir.

    This paper illustrates the complicated interaction between PBL shear,
    synoptic wind shear, and diurnally varying turbulence even over flat
    homogeneous terrain.

  • McNider and Pielke, 1981: Diurnal boundary layer development over
    sloping terrain. JAS

This paper illustrates how the nocturnal low level jet can be amplified
in response to thermally forced mesoscale systems.

  • Pielke et al, 1885: Derivation of slope flow equations using two
    different coordinate representations. JAS

This paper describes an application of tensor transformations for a
simple 2-D slope flow model. It also illustrates the turbulence that is
produced as the sfc friction and the entrainment of air at the top of the
slope flow result in a low level jet.

  • Sellers et al, 1997: BOREAS in 1997: Experiment overview, scientific
    results, and future directions, JGR
  • Sellers et al, 1992: An Overview of the Firt International Satellite
    Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE). JGR
  • Pielke, 2001: Influence of the spatial distribution of vegetation and
    soils on the prediction of cumulus convective rainfall. Rev of Geophysics..

Assignment 10 - Date Assigned: September 25, 2001

  • For class tomorrow morning, please make sure to bring the papers that were handed out. I will give out again the one paper that needed to b recopied. Also, this is a good time to ask questions about the problems that have been assigned, On Wed for our 12:10-1pm class, I plan to discuss radiative flux divergence. I will be using parts of Chapter 8 from my modeling book.

Assignment 9 - Date Assigned: September 20, 2001

  • On Tuesday, we will continue with Chapter 12 and the handouts I provided in class. If you would like, you can pick up the other paper from Dallas and/or Tara before class; otherwise, I will bring to class.

Assignment 8 - Date Assigned: September 19, 2001

  • Read Chapter 12 and Reviews of Geophysics paper handed out in class. Problems 2-3, 4, and 6-10 are assigned.

Assignment 7 - Date Assigned: September 18, 2001

  • For Chapter 11, problems 1, 5-6, 8-9, 14-15 and 19 are assigned.

Assignment 6 - Date Assigned: September 13, 2001

  • For problems in Chapter 10, focus on 1-3, 5, 8, 10-11 and 14-17.
  • Two articles on reserve in the library by Sellers et al.
  • Please read Chapter 11

Assignment 5 - Date Assigned: September 11, 2001

  • In Chapter 9, problems 1-2, 4, 10-16, 21, 23-24, 28-29 and 31.

Assignment 4 - Date Assigned: September 6th, 2001

  • Read Chapter 9
  • For Chapter 5 focus on problems 1-2, 4-6, 9, 11-13, 19-22, 24-25, and 28-32.
  • Rosenberg et al. is on reserve on the ATS library. It is recommended you review the text in that book on the different types of instruments.
  • Announcement of midterm exam which will be Tuesday, October 23rd

Assignment 3 - Date Assigned: September 5th, 2001

  • In Chapter 4 problems 2-4, and 9-10 in Chpater 4
  • Read Chapter 5.

Assignment 2 - Date Assigned: August 30th, 2001

  • Read Chapter 4
  • In Chapter 3, problems 3, 5, 8, 13, 14, 17, 21, 23, 26, 27, 29 and 30 are assigned.

Assignment 1 - Date Assigned: August 28, 2001

  • Read Chapters 1 and 2
  • Complete problems 6c and 11 in Chapter 1
  • Complete problems 1-9, 11, 12, 14-17, 22, 23, 24, 26-28 in Chapter 2. For problem 12, make this part of your class term paper.
  • Select a model for which you will diagnose their turbulent parameterization. In your analysis (which will be presented in a 15 minute talk at the end of the semester) derive the parameterization and state its assumptions. Include what conditions for which it is likely to fail to be accurate. Include in your discussion, the basic input variables it uses, and its adjustable and "universal" functions and parameters.
  • Read Chapter 5

Your talks should be ~15minutes in length, and presented the week of
November 12th.

The following are the class presentations.

1. Russ Chibe: the RAMS Mellor-Yamada and Deardorf turbulent

2. Liz Zarvoy: An air chemistry model approaved by EPA; its PBL
formulation (RADM's PBL)

3. Jesse Ryan: the Goddard Cloud Ensemble PBL scheme

4. John Strack: the CCM3 PBL

5. Chris Castro: Holtslag PBL scheme

6. Tim Nobis: The MM5 PBL

7. Russ Schumacher: ETA PBL

8. Justin Shaw: the PBL of the MRF model

9. Gustavo Pereira: INPE PBL if different than USA version of ETA

Research Group: