The impressive height of the cells is indicated by the length of their shadows cast on the earth's surface to the east of the line in northeastern Nebraska and northwestern Iowa.
Science 123 |
Spring 2020 |
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Page One |
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The satellite image to the left was taken about 4:30 PM on Saturday, July 26, 2007. A very impressive line of supercellular thunderstorms developed along an advancing cold front.
The impressive height of the cells is indicated by the length of their shadows cast on the earth's surface to the east of the line in northeastern Nebraska and northwestern Iowa. |
As a reminder, the schedule for the second seven week is suggestive and made to give someone target dates to help keep on track to finish all requirements without have too much to do near the end of the term. However, I will accept any new assignment (made in the second seven weeks) up to the last day of the semester, May 21. Reading quizzes from the second seven weeks will remain open until the midnight of May 21 as well.
The Minneapolis sounding shown above exhibits what is known as an "inverted V" pattern. The temperature plot (in red) and the dew point plot (in green) form an upside down V in the near-surface layer. Notice that the environmental lapse rate follows the dry adiabatic rate. This will result in a rather windy day as parcels warming at the surface will rise relatively easy and be replaced with cooler parcels from above. Even though the atmosphere is not very stable, there will be a limited chance of precipitation of the convective variety because the lower atmosphere is extremely dry. So dry (low relative humidities), that the gusty winds and dryness will create a fire hazard possibility.
The outline for the chapter on thunderstorms (Chapter 13) has been updated to include video segments covering the main topics. The last reading quiz, covering lightning, thunder and tornadoes, will be opened Tuesday, May 5 at 12:00 noon.
The outline for the chapter on atmospheric stability (Chapter 12) has been updated to include the links to videos. There are two example exercise videos, one for Exercise 1(a) and 2(a), and the other for Exercise 3 from the exercise set for the chapter. NOTE: Exercise 5 and 6 from the problem set involve plotting and analyzing sounding data. They will be treated as extra credit.
I have re-worked the weighting scheme for determining your semester average score. There are four items (the Katie Gradebook Designator is shown in parentheses): Reading Quizzes (RQx), Homework Exercises (HE), an Exam (EX) and the Semester Paper (SP). Each would carry a weight of 0.25 if weighted equally. However, the following adjusted weight scheme will be used. The exam score will carry a weight of 0.25. The weight assigned to the other three items will be 0.40 for the highest, 0.25 for the next highest and 0.10 for the lowest.
As an example, consider the table shown below:
| Item | Ave. Score (%) | Equal Weight | Adjusted Weight |
|---|---|---|---|
| Reading Quizzes | 75 | 0.25 | 0.25 |
| Homework Exercises | 35 | 0.25 | 0.10 |
| Exam | 80 | 0.25 | 0.25 |
| Semester Paper | 92 | 0.25 | 0.40 |
| Semester Average (%) | 70.5 | 79.05 |
I have adjusted the Katie gradebook using the Equal Weight scheme shown in the table. This will provide you with a "lower limit" of your semester average percentage and what your semester letter grade (see the next paragraph) would be based on the equal weight scheme.
The next step is to determine the semester letter grade based on the semester average score. Whatever scale I use, the class GPA for this term will be at least as high as the course historical average of 3.15. The letter grade scale used for the January Term 2018 offer is shown in the table below. If need be, I will lower the cutoffs by one point until the class GPA reaches the 3.15 target. I will NOT raise the letter grade cutoffs under any circumstance.
| Grade | Min % |
|---|---|
| A | 92 |
| A- | 88 |
| B+ | 84 |
| B | 80 |
| B- | 75 |
| C+ | 70 |
| C | 65 |
| C- | 60 |
| D+ | 55 |
| D | 50 |
| D- | 45 |
Your responsibilities for the second seven weeks are as follows:
Assignment Hand-in. Please submit homework solutions in using your Science 123 Google folder I created for you. You should have received an email about two weeks ago informing you of the Google folder. If you log into your Google drive, you can also access the folder by clicking the "Shared with me" link.
There are several options for uploading a pdf document.
We had our first virtual office hour yesterday. A good number of people showed up. For many, it served as a confirmation that we are still "connected." For me, I learned more about how to set up and manage a virtual office hour. I have invited each of you to the scheduled office hour for the remaining portion of this semester through your Norse Apps Google calendar. If you did not join in yesterday, I encourage you to try to make the next "meeting" on Google Hangouts Meet. Here is what you will see by clicking the item on your calendar:
Then, click on the "Join Hangouts Meet." Note that the time is scheduled for 4:00 PM CST on April 2. One of the primary objectives on Thursday will be answering questions about Chapter 9 homework exercises. On that matter, I will be posting answers to the even-numbered exercises I assigned from the exercise sheet on the Homework Help page for unit 2.
There is a link on the web page to the schedule for the second seven weeks of the term. The schedule is tentative. I am including suggested due date for items such as reading quizzes and the few remaining assignments. These dates are not hard and fast. I will accept any new assignment (made in the second seven weeks) up to the last day of the semester, May 21.
Virtual office hours have been set and I have invited all of you to attend through your Norse Apps Google calendar, but attendance is not mandatory. If you want to attend, click on the event in your calendar, and then click on the "Join Hangouts Meet" option. My "office door" will be open for the hour, so feel free to drop in and listen if a conversation is on-going, or start a new conversation if one is not in process.
If you are unable to attend a scheduled drop in office hour and want to talk about course material, please send me an email and we will work to find a virtual meeting time, or I will answer your question directly in an email response.
The Chapter 9 outline and material has been updated. I have included links to video snippets for the various main chapter topics as well as guidance on some of the odd-numbered exercises of the Chapter 9 Exercise Set. The Chapter 9 Katie reading quiz (RQ9) will open March 24 at noon. It will close Thursday, May 21 (the last day of final exam week). The remaining reading quizzes will be made available once I have made some slight changes. Each of the remaining Katie reading quizzes will remain open until May 21.
I hope you are well and have made it to your destination since leaving the Luther College campus (if you have left). I want to communicate some information to those of you who were not able to attend our last face-to-face meeting as well as expand the "moving forward" information provided in class on Tuesday, March 17.
It is fortunate that we have covered roughly 2/3 of the semester material in the first half of the course. Even so, our abrupt change in format prompts me to realize what may be accomplished in the second seven weeks will need some "scaling back" as well. Even though I hope we have only "manageable" challenges ahead, if any, I have to realisticly expect that you may encounter unique and difficult situations over the balance of our spring term. Consequently, I intend to be flexible in the amount of material we will cover and due dates for quizzes, assignments and other issues.