ATMS 411 Homework [Main Page] [Daily Notes] [Final Project]
Homework style example.
ONLINE ASSIGNMENTS ARE GIVEN IN WEBCAMPUS.
ASSIGNMENT DUE DATES ARE GIVEN IN WEBCAMPUS.
Emphasize understanding of the physical quantities used to describe atmospheric thermodynamics.
Relate atmospheric thermodynamics to hurricane dynamics as a real world application.
Practice using the skewT graph and Python programming for atmospheric thermodynamics.
Make one MSword document that has solutions for problems 1 through 4.
Read chapter 3.
1. Define and discuss the following quantities (in your own words. Read about them from various sources and then from memory/understanding, discuss them).
a. Tv virtual temperature
b. Tdew dew point temperature
c. Tw wet bulb temperature
d. θ potential temperature
e. θw wetbulb potential temperature
f. θE equivalent potential temperature
2. Explain in words (no diagram needed) how to use Normand's rule to obtain the following:
a. Dewpoint temperature from the temperature, pressure, and wetbulb temperature.
b. Wetbulb temperature the temperature, pressure, and dewpoint temperature.
3. Create a program using Python for obtaining Tdew given values typical for the class room air To=21.3 C, wet bulb temperature Tw=12 C and Po=871 mb.
We will develop the theory for this problem in class, the pertinent notes are here.
Also report ws(Tdew), ws(Tw), ws(T), RH, θ, θw, θE, and the LCL temperature and pressure.
The LCL calculation requires inputs of Tdew, To, and Po
This program is a starting point, and it has the LCL calculation in it.
Add your code for obtainining the dewpoint, or write a separate program.
Compare the Python results with values from a skewT diagram.
You can check your dew point calculation with the National Weather Service water vapor calculator.
a. Skew T diagram showing how Normand's rule, etc, to obtain the quantities listed below, and values entered into the table.
You can copy and paste this table into Microsoft Word and fill it in. You can delete the "Procedure using skewT" column.
|Quantity||Units||Value from skewT||Value from Python||Comment||Procedure using skewT|
|Tdew||C||dewpoint temperature||Use Normand's rule|
|ws(Tdew)||g/kg||water vapor mixing ratio at saturation at the dewpoint temperature||Read from the skewT|
|ws(Tw)||g/kg||water vapor mixing ratio at saturation at the wetbulb temperature||Read from the skewT|
|ws(T)||g/kg||water vapor mixing ratio at saturation at the air temperature||Read from the skewT|
|θ||K||Potential Temperature||Follow the dry adiabat through T down to P=1000 mb and read the temperature.|
|θw||K||Wetbulb Potential Temperature||Follow the moist adiabat throughTw down to 1000 mb and read the temperature.|
|θE||K||Equivalent Potential Temperature||Use Normand's rule to get to the LCL. Then follow the moist adiabat to the top of the atmosphere. Return to 1000 mb along a dry adiabat and read the temperature.|
|LCL Temperature||C||Temperature at the lifting condensation level (LCL)||Use Normand's rule|
|LCL Pressure||mb||Pressure at the LCL||Use Normand's rule|
b. Screen shot of Python program and output, and values entered into the table.
4. This problem explores hurricane dynamics and thermodynamics.
It will be in short report format as discussed in Homework 2, this time with references.
At the center of a hurricane is a warm core low pressure region, the eye of the hurricane.
This table gives a categorization of hurricanes by maximum wind speed range. (local backup).
a. Discuss the life cycle of hurricanes: formation, energy source, and dissipation (be sure to cite your references, see Resources.) (one paragraph for each, with inline references to the literature you cite/use).
b. Create a 'hurricane' table with headings Category, Sustained Wind Range (m/s), Eye Pressure Range (mb), Average Eye Temperature Difference (C).
We will use cyclostrophic flow theory in class to show that the pressure difference between the eye and the surroundings is ΔP=1.81ρv2 where ρ is surface density and v is maximum hurricane wind speed.
Use the eye and surrounding pressure to assumed to be 1010 mb to obtain the average temperature difference between the atmospheric column above the eye and surroundings (see prob 3.26).
[We showed that ΔT=Toln(Po/Peye)/ln(Peye/200mb) where To=-3 C = 270 K, and Po=1010 mb.]
This paper discusses hurricane properties.
You can reference it in your report, comparing your values with those in the paper, and find other references for hurricanes using the Web of Science.
We will discuss in class how to use cloud applications for EndNote and WebOfScience to manage references within Microsoft Word (download and install the Endnote plugin for Word).
We did problem 3.26 in class to develop theory for the average column temperature difference and the hurricane eye pressure given the wind speed.
National Hurricane Center site and data.
Study the introductory chapter for an overview of the field.
Access and interpret sounding and reanalysis meteorological data from around the world.
Calculate and graph meteorological variables to investigate their vertical distribution in the atmosphere.
Learn how to make and interpret publication quality graphs for meteorology.
Advance science writing skills.
Make one MSword document that has solutions for problems 1 through 4.
Read chapter 1.
1. Do problem 1.6 parts a, c, d, and i. Write your answers into the first part of the MSword document you will be turning in for this assignment.
2. Do problem 1.12, being sure to express your answer in degree C per kilometer.
Then go to the South Pole and find a sounding that best resembles the features of this problem.
Soundings from the South Pole are at Amundsen-Scott station 89009 in Antarctica.
Look at data from perhaps June through August and find a day with cold surface conditions and a strong inversion calculated from the first two points.
You can put the station number 89009 in the website and press enter to access this data.
3. Prepare a short report that describes the atmosphere for 00Z, 5 January 2021 for these two locations, Rochambeau French Guiana (SOCA, Station 81405) and Barrow Alaska USA (PABR, Station 70026)
a. Use Google Earth to view these two locations, Rochambeau French Guiana (coordinates 4.8222, -52.3653) and Barrow Alaska USA (coordinates 71.2889, -156.7833). Save images of each location and use as figures 1 and 2 in your report.
Include grid lines in these images so you can see the Tropic of Cancer and the Arctic Circle, respectively, and discuss the significance of these geographical demarcations,
both in of themselves and with respect to the amount of solar radiation expected to be seen seasonally in their vicinity.
b. Acquire the png format skew T soundings for PABR and SOCA for this day and time. Make these soundings figures 3 and 4 in your report.
Discuss these soundings. What is the local standard time at each site for the soundings?
Observe the lapse rate Γ=-dT/dz from the slope of the temperature versus height graph and interpret.
c. Near equator: Rochambeau French Guiana (get sounding text for SOCA from the Wyoming site.
Plot pressure and temperature vs height as figure 5 in your report.
Calculate density and plot versus height in a separate graph as figure 6).
d. Near north pole: Barrow Alaska (PABR).
Get the sounding data for PABR from the Wyoming site.
Overlay pressure and temperature vs height with the SOCA pressure and temperature in figure 5.
Calculate density and overlay with the SOCA density in figure 6.
e. Calculate and graph the water vapor density in grams/m3 for Barrow and overlay with the SOCA water vapor density, as figure 7.
Note that water vapor density is the product of density * w. Discuss.
f. Then make a graph and fit a trendline for the natural logarithm of pressure, ln(Pressure) vs height
to obtain the scale height of the atmosphere at these two locations,
considering data to a height of 2 km.
Include this graph as figure 8.
Here's an example of scale height.
In your report, compare and contrast the difference in the meteorology between these two sites
as a function of height in the atmosphere, both near the surface and throughout the atmosphere.
NOTE: A short report should be written like a short section in a text book.
A. Title for the report. Your name.
B. The first paragraph(s) describes what's in the report, describes what is to be accomplished. References to other literature should be in the name year format, e.g. Smith et. al. 2020.
C. Each figure must have a number and a caption. Figures must be in publication format -- high quality figures with 18 point (or greater) bold black font; tick marks inside. All axes 1 point thick and black.
D. Each figure must be discussed in the text by number, describing the significance of the figure and its relationship to other figures as needed.
E. Any equations should be offset, as in a textbook, and each equation should have a number. Refer to equations by number. Use the equation editor in microsoft word to prepare your equations.
F. The last paragraph should summarize the overall outcome of the report, and possibly discuss your results in comparison with literature results as in part B.
Get started early.
G. List of cited references.
Take advantage of the UNR writing center to have them read your report draft to give you feedback on writing quality.
A. Meteorological data can be obtained from the University of Wyoming web site. Backup of data in case the website is down.
B. Most (or all) computers readily accessible to all students, using their netID, have Google Earth, MSword, and Excel.
C. Students can download office for their home computer. Excel and Word are available for students and faculty here. Sign in with your UNR netID and download Office to your computer. We will import data using the text wizard: Excel:File:Options, then check this box.
D. Description of balloon soundings of the atmosphere.
E. References to published papers and websites can be easily managed with EndNote. Scroll down to "Manage your references" for instructions.
4. a. Do problem 1.21 in the textbook. This is similar to problem 1.20. The answer is around 2.5 mm⁄sec. Show that the air speed is v=(dp⁄dt) RE ⁄ Ps where RE is Earth's radius and Ps is the average surface pressure and evaluate using Python (include in your report).
b. Here are graphs of the surface pressure averaged from 1950 - 2019 for Dec/Jan/Feb and for June/July/August.
[This data is from NCEP/NCAR. One objective of this problem is to become aware of this data].
[Data from NOAA, Physical Science Laboratory, Monthly/Seasonal Climate Composites]. Historical data is available in another form here.
c. Does the pressure distribution support the premise of part a?
d. Discuss the seasonal variation of surface pressure in the Northern hemisphere in summer and winter, locations of highs and lows, and meteorological consequences. (open ended question).
This topic is discussed in this online dynamics textbook near Figure 2.3, the pertinent section is here.
e. Extra credit: Here are data and graphs for 2020. The data is in netCDF format, and it could be averaged to look at this problem analytically.
Skew T lnP Practice homework based on the atmosphere of 17 August 2021:
Reno sounding location is 72489 REV. Slidell Louisiana sounding location is 72233 LIX.
Instructions: Place your results from parts 2, 3, 4, 5 , 7 and 8 into a Microsoft Word Document and submit it to Webcampus.
1. Download the blank skewT graph to Microsoft Paint, or your favorite image program.
2. From the Reno morning sounding, write down the temperature and dewpoint temperature for pressures of mb of 845, 700, 500, 400, and 250 mb. (Local backup).
3. Put these points on the blank skewT graph using Paint and save your skewT image file.
4. Download the actual sounding for the morning and circle the temperature and dewpoint temperature values at the pressures given in part 2. (Local backup).
5. Compare with your skewT from part 3 with the actual sounding in part 4 to make sure you are understanding these charts.
6. Bring questions to class.
7. Download the Slidell Louisiana 12Z sounding and compare with the Reno sounding. (Local backup).
8. What are the local times in Reno and Slidell at the time these soundings?
Some skewT lnP applications and measurements.
Skew T lnP MetEd Module that covers nearly everything, starting with the basics.
ATMS 411 in class presentation and turn in presentation here.
ATMS 611 in class presentation, report, and turn in presentation here.
Presentations are 5 to 20 minutes long depending on the number of observations and types of data used.
Atmospheric Physics students take photographs or other data of the atmosphere or environment, and explain the Atmospheric Physics connection.
You can use more than one photograph, and can look at a variety of phenomena.
For example, blue sky, sky polarization, coronas, halos, rainbows, lenticular clouds, gravity waves, lightning, water phase clouds, ice phase clouds,
inferring air motions and winds from cloud structures, contrails, vortices in contrails, sky color during pollution events, sky color near the horizon, sky color at sunset looking to the east.
Photographs of the dendritic nature of ice growing on windshields on cold days, the shape and nature of icicles, dew on a moist mornings are also possible topics.
Photographs of snow flakes and snow crystals, here's a discussion.
If you have special hobbies or work, like paragliding, Atmospheric Physics related aspects can be included in your project.
You can use soundings, satellite images, weather station data, etc, to also help tell the story.
ATMS 411 students will do a presentation. Presentation hints. 7 secrets of great speakers. Teachable moments.
ATMS 611 students will do a presentation and a report. Report format.
Presentations: December 1st by 8 am. Presentations start that day. Turn in your presentation through webCampus.
Reports: December 7th by the end of the day. They can be submitted as a second file through webCampus.
Resources that may help
Gravity wave discussion.
Snow crystal/flake observations.
NASA WorldView for satellite imagery. You can add layers for additional information.
National Weather Service balloon soundings, served by the Univ of Wyoming.
Weather station data from the Western Regional Climate Center at DRI. In particular, the UNR weather station.
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