Monday May 2, 2011

Several songs (composed by Yann Tiersen) from the movie Amelie ("Comptine d'Un Autre Ete", "Les Jours Tristes", "La Valse d'Amelie", "A Quai", and "La Valse des Monstres")

The Teacher Course Evaluation was conducted today.

Grade summaries were handed out in class today.  They will tell you whether you DO  or  DO NOT  have to take the Final Exam.  Please check over all the scores carefully and let me know if you find any errors or omissions.

There were a couple of brief points to mention about hurricanes before wrapping things up this semester. 

First the Saffir Simpson Scale is used to rate hurricane intensity (just as the Fujita Scale is used for tornadoes).  Here's a relatively easy to remember version.


All you really need to remember is that the scale runs from 1 to 5 and that winds in a hurricane must be 75 MPH or above.

In this easy to remember version, pressure decreases by 20 mb, wind speeds increase by 20 MPH, and the storm surge increases by 5 feet with every change in level on the scale.  Category 3 hurricanes and above are considered major hurricanes.

The storm surge is a rise in ocean level when a hurricane make landfall.



Winds sweep surface water in toward the center of a hurricane and cause it to pile up.  The water sinks and, in deeper water, returns to where it came from.  This gets harder and harder to do as the hurricane approaches shore and the ocean gets shallower.    So the piled up water gets deeper and the return flow current gets stronger.

Here is a link to the storm surge website (from the Hurricane Research Division of the Atlantic Oceanographic and Meteorological Labororatory).  It has an interesting animation showing output from the SLOSH model used to predict hurricane storm surges and the flooding they can cause.


A hurricane is approaching the coast from the east.  Where will the fastest winds be, on the north, east, south, or west side of the hurricane?

The fastest winds will be on the north side

On the north side of the hurricane the direction of motion and the direction of the winds are both in the same direction.  They add.  The winds are effectively 115 MPH on the north side.  On the south side the winds are pointing opposite the direction of motion.  Now you subtract the speed of motion from the wind speed.  The winds are 85 MPH on the south side of the hurricane.  The greatest storm surge and greatest damage often occurs a little to the north of the point at which the hurricane make landfall.

Here are details of the two calculations that I did in class showing you what score you will need on the Final Exam to either preserve your current grade or raise your grade.

We used a current grade of 85.4% as an example.

In the first case the question becomes how badly can you do on the Final Exam and keep a B.  In this kind of a situation the Final Exam score is 20% of your overall grade. 


With a current grade of 85.4% you'd only need to score 58.5% on the Final Exam to keep a grade of B.

If your Final Exam score is high enough to raise your overall average then I will count it as 40% of your grade.  Here's the calculation you need to do to determine the grade on the exam needed to raise your current grade to an A.


You'd need to score 97% or above on the final to raise your grade to an A.  That won't be easy but it is possible.  There will be several extra credit questions on the Final Exam and I am pretty sure there will be some students that do this well on the exam.

And with that we came to
THE END
of what we will be able to cover in NATS 101 this semester.  In class on Wednesday we will begin the  review for Friday's Final Exam.
also I have promised several people one more opportunity to earn some extra credit, so there will probably be some kind of optional in-class assignment on Wednesday