Homework # 2 Solutions

 

1.) Over the past three hours, a tipping bucket with a .01 inch cup tipped 260 times.  What is the average hourly rainfall rate in inches per hour?

 

First, you need to find how much total rain has fallen.  To do this, just multiply the volume of the bucket times the number of tips.

 

.01” x 260 = 2.6 inches of rain within the past 3 hours. (If you got to this, I gave 1 point.)

 

The last part of the question asks for the hourly, average rainfall.  The problem stated that the rainfall amount occurred over three hours.  Therefore the hourly rate is:

 

(2.6 inches) / (3 hours) = .8667 inches of rain per hour (As long as you were close to .86, I gave you full credit.)

 

2.) If the Sears Tower (which stands 1,353 feet tall) was the only building in Chicago, what’s the minimum distance (in feet) from the Tower that an anemometer can be placed in order to get an accurate measurement of the wind?

 

This is simply 10 times the height of the Tower.

 

10 x 1,353 feet = 13,530 feet

 

3.) What is the most common type of anemometer in use, according to the notes?

 

            Cup anemometer

 

4.) What are 4 of the 5 advantages that make the thermoelectric thermometer (and other instruments) good to use in automated stations? (Each answer was worth ˝ a point, up to two points.)

 

-         Rugged

-         Reliable

-         Wide temperature range

-         Inexpensive

-         Fast response time

 

5.) What are the four major air masses that control the USA’s weather?  (Each answer was worth ˝ a point.)

 

-         Continental Polar

-         Continental Tropical

-         Maritime Polar

-         Maritime Tropical

 

6.) List the locations where the four major air masses originate.  (Each answer was worth ˝ a point).

 

-         Alaska and Northwest Canada

-         Deserts of the Southwest and Mexico

-         Northern oceans

-         Gulf of Mexico and the Caribbean

 

(Some people in question 5 listed four types of winds.  If you did that and gave the proper location for where those winds occurred in question 6, I gave you full credit for question 6.)

 

7.) What makes the cup anemometer inaccurate in gusty wind conditions?

 

            For this, I was looking for something about momentum.  A gust of wind will accelerate the spinning of the anemometer, but when it dies out, the momentum of the anemometer will keep it spinning for a few more moments, registering a higher average wind speed.

 

8.) At a weather station, to ensure that a shadow from the tower never falls on a solar panel (which measures the Sun’s energy that hits the ground), the solar panel must be located on which side of the tower (north, south, east, or west) as long as you are at a latitude above 23.5 degrees N?  (Hint: Look over the information concerning the equinox and solstice in the reading.)

 

            This answer came from page 16 of the reading.  The illustration at the top of the page shows how the Sun never goes above 23.5 degrees North during the summer solstice.  Therefore, the Sun will always be “south” of any locations on the Earth above that latitude year round.  That makes the south side of the tower the place to put your solar panel.

 

9.)  What does ASOS stand for?

 

            Straight from the notes, this means Automated Surface Observation System.

 

10.) In class, we briefly mentioned the Oklahoma Mesonet.  For the next question (and for some interesting reading on the Mesonet) use the following website.  http://okmesonet.ocs.ou.edu/overview/

 

What is a brief definition of “Mesonet”?

 

I was simply looking for the fact that “Mesonet” is a combination of the words “mesoscale” and “network”. 

 

However, many of you managed to out-smart me.  You put down a much more complete meaning of what the Mesonet is and I gave you full credit for the question, as you answered what I asked.