Sunday, April 6, 2014

For my G109 students: air pressure experiment

I had a water bottle open on my flight today, and closed it while we were at cruising altitude (so the pressure inside the plane was about 850 millibars).

Once we were almost on the ground in Atlanta, I pulled it back out.  With the air inside the bottle sealed at 850 millibars, but the cabin now back to around 1000 millibars, I opened the bottle and...

https://www.dropbox.com/s/yqivni0ces4so63/20140406_125554.mp4

Thursday, March 20, 2014

Spring tornado drills

Here's the timeline of how I received the evening's Test Tornado Warning from various sources, including the National Weather Service, through my cable television provider, and other channels related to the largest employer in my hometown.


7:36 p.m. All three of my NOAA weather radios went off.

7:37 The TV is on pretty loud...  "Did you just hear sirens?"  "I'm not sure."  (Yes, they were going off.)

7:38 Tweet from @IUEMC.

7:39 EAS activiation on all cable TV channels.

7:40 Email from "IU Notify" system arrives.  It was time-stamped at 7:37, but took 3 minutes to get through the getrave.com servers to my inbox.  (I verified this by looking at the email headers.  I'll be happy to provide a screen capture of them.)

7:42 Tweet from @IUBloomington.

7:49 The average "lead time" for a tornado warning is 13 minutes -- meaning a tornado could have just hit your home.  How much lead time would each system have given you?  Backtrack from here.

Friday, March 14, 2014

The sling psychrometer

Want to learn a few German words? Just check out the psychrometer from our cabinet at work... a.k.a. das Schleuderpsychrometer.

(If it's der or die instead of das, let me know.)

Sunday, February 16, 2014

Mine, all mine

One of the best, straight-talk summaries of the role of Twitter profile disclaimers in this day and age:
http://www.cyberbuzz.com/2011/08/22/the-views-are-mine-and-not-my-employer/
"You see Twitter disclaimers more and more these days. It’s a variation on the “the views are mine and not my employer”, or “opinions expressed here are mine and mine alone” theme.
Guess what?

Those opinions may be yours and they may not reflect the opinions of your employer, but they reflect you."
For the record, I do endorse this view.  :-)

Your boss isn't going to go look for a disclaimer before he fires you for publicly being an idiot and dragging down the company's brand.  If you put your affiliation directly on your profile, then you are acting as a very public, full-time ambassador for that group -- whether it be your government employer, your university, or your burger joint.  And everything you post could get associated with that group, no matter whether you "disclaim" it or not.  That's all the motivation some employers will need to give you the axe, or maybe even not hire you if they trawl your past posts.

A while back, after someone I know got in a little row with some folks over a couple insensitive posts, they retorted "I don't know what the big deal is, it's just Twitter."  Tell that to its billionaire owners, countless news media outlets, or to the Library of Congress

Sunday, January 19, 2014

Spring 2013 and Fall 2013 semesters of teaching

(As I said in the intro to my first semester summary, I want to keep some notes here on the successes and failures from my teaching exploits.  It's mainly for my reference, but there's no reason not to share my successes and failures with everyone else.)  Here's a wrap-up of...

Semester #3 - Spring 2013 - 3 classes
* Lower division intro to weather & climate, 100 students
* Lower division earth system science, 50 students
* Upper division synoptic meteorology, 15 students

I learned a lot about myself this semester.  The weather and climate course began to click, with the just-in-time methods and classroom activities and other assessments.  Now I just need to make some changes to the lab manual, which I inherited from a previous instructor and which doesn't match my style (or content) as well as it should.  Since I didn't draw this course again in the fall, I didn't work on it over the summer.  Maybe I should have.

Our weather analysis-synoptic sequence is taught without the prerequisites of physics and calculus, and it's incredibly difficult--more than I thought--to teach synoptic concepts without it.  How many of you have ever tried to teach QG theory in words?  :-)  It can be done, but it's a slow process.  I really like the Lackmann book, but it's not the best fit for a conceptual synoptic course in my opinion.  I resorted to a lot of Vasquez's material, as well as Chaston's old book.  He has probably the best descriptive QG section out there, that I've seen.

My first foray into my new departmental home was ESS, with a few majors but mostly as a service course as are many 100-level courses.  I struggled with what kind of theme I wanted the course to take--again, given that I inherited a lab manual that in no way reflected my pedagogy--and eventually decided on a tour of the earth system: a few weeks of each of the four (five?) spheres.  And my goodness, if you want to know where your knowledge of a topic is weak, don't do your homework and then go to class in an activity-based course design!  I did learn that students are okay with you saying "I don't know," to a point.  It shows that we're human, that we don't have all the answers either.  I think many of them resonate with that.
 
Semester #4 - Fall 2013 - 3 classes
* Lower division intro to atmospheric science, 10 students
* Upper division climatology, 25 students
* Upper division mesoscale meteorology, 20 student

I moved the "weather and climate" course across campus to a new department and gave it a new name, with lab exercises of my own, and it felt really nice.  One problem: just as small-classroom exercises definitely do not scale up to lecture halls, large-classroom activities don't scale down to a room of 10 students, either.  More than once, an activity that would take 2-3 minutes in a room of 100+ students would be over in 30 seconds.  "Well, that usually takes a little longer."  It didn't hurt that I had an incredibly bright group.  So we improvised with more data, or went to the web for more photos, etc.

This may disappoint a few folks but I'm not going to say much about the mesoscale course, because most of the previous struggles (mixed grad/undergrad, no math and physics prerequisites, etc.) and successes (use of case studies and real events, individual vs. group presentations, etc.) came up again.  It was fun to take the course as I'd taken it--all lecture by powerpoint--and tweak the topics and change the presentation.  Much fun.

Climatology was a new prep for me but also a fun one; I'd taken a couple of graduate courses in it and it's a hot topic in mainstream science, so I felt ready.  Key takeaways:

* Flexibility in the entire course plan.  I hadn't wanted to talk about the Milankovitch cycles until we introduced past climates & Earth's climate history, but students wanted it during the radiation physics section.  So I had to shift everything.

* Don't hesitate to abandon ship.  On "what causes the jet stream" day, I tried to leap too far too quickly (it's temperature gradients ultimately, btw).  The handouts I distributed weren't matched up with what I wanted to say, the way I said it didn't match up with what they had read, and about 30 minutes into the (75-minute) period I realized this boat was a goner.  "Okay, class is over.  That's it.  Come back Thursday."  We did, I revised and resubmitted, and it went much better the second time.

* Students love real life.  As we got to a section on ice ages and glacier formation, a winter precipitation event presented itself.  So we spent a day on precipitation types and vertical temperature profiles, looking at observations and making forecasts, and so on.  They seemed to really enjoy that.
 
What will Spring 2014 hold?  Enrollments of 100 and 30, I know that much.......
 

Friday, November 1, 2013

Ginkgo biloba phenology

I've been taking photos of one of the ginkgo biloba trees on campus as it changes colors this season -- I'll post the set some time next week once the color really pops.  (The leaves are about half green, half yellow right now.)

Saturday, October 19, 2013

NCAA FBS "Points Per Yard Allowed"

Maybe Wayne Winston should add this to his second edition of "Mathletics."

This is the number of yards a team must gain for every 7 points they put on the scoreboard.  (That's the inverse of "points per yard allowed," which is in the title.)  The formula:  7 / (total defense/scoring defense).

In other words, teams that score 14 points against Alabama will have an average of 343 yards.  It takes only 280 yards to amass 14 points against BYU.  By the way, #123 in this list is Southern Miss, with 71.5 yards. That 343 yards you manage against Alabama would get you 33-34 points against USM.