Rain Shadow of the Himalayas

The picture above is a satellite view of the Tibetan plateau, found north of the Himalayas. The green land to the south of the Himalayan mountains is India, which receives enough precipitation to support a tropical rainforest. North of the mountain range you can see a great plains region and the Gobi Desert; areas that receive very little rainfall. How can we account for such a change in the amount of precipitation each place receives? The short answer is "rain shadow", and it happens in the United States as well. It is largely the reason that Western South Dakota receives approximately 5 less inches of rain per year than we do here in Sioux Falls.
In your response on Classmarker (it will be on the Fronts and Air Masses Standard Check), explain what happens to the air mass that initially forms over the Indian Ocean as it travels north. Why does this process leave so much precipitation on the south (windward) side of the Himalayas, and hardly any to the north of them?
Note: You should answer this question on Classmarker. It will be worth 4 points.

Relative Humidity Data Results

View Relative Humidity Lab - Spring 2012 in a larger map Click on each placemark to find the average relative humidities from all of the data samples taken on Monday. Are there any patterns? Compare the inside locations to the outside locations -- that's one pattern I saw. In fact, the four highest relative humidity values were from inside the school. What might have caused this? There could be many factors that would influence our numbers. Please explain. Don't run away from the struggle.

Humidity Questions

Here are the essay questions about humidity that you can complete when you're ready on Classmarker.

1. Suppose it is summer (YES!!) and you plan to have a glass of iced lemonade outside. You notice that water drops begin form on outside of the glass. Why does this happen? Where does this water come from? (2 points)
2. A person's body tends to sweat more on a humid day than it does on a dry one, even if the outdoor temperature is exactly the same. Why does it happen this way? (Hint: Your answer should include how evaporation changes the temperature of the air.) How does this relate to how we measure relative humidity? (Hint #2: Would a large difference between dry-bulb and wet-bulb temperatures signify dry weather or humid weather?) (4 points)

Relative Humidity Lab Form

Pressure in a Bottle

Crushing Cans with Air

This is what I do. Here's the procedure:

• Place 8-10 ml of water in an empty pop can.


• Place the pop can onto the heat source and wait for the water to boil. After you see steam escape, continue to boil for one minute.


• Use the tongs to remove the can from the heat. Quickly turn it upside-down and place it into a saucer with water (which was close-by).

In your blog response, explain what happened in this experiment step-by-step. Justify the result that you saw? What happened inside the can as it was being heated up? What does the air do? How about when it was placed in the water? Why was it crushed? Did a ghost do it?

After completing these questions in your comment, check out some "Pressure" flash cards on Ediscio, or look at the following pressure websites. Otto von Guericke makes a vacuum Toricelli's Barometer video Air Pressure Balloon Animation Storm System Animation

Power of Air Pressure

Air Pressure is the Best Around from Owen Hoegh on Vimeo.
Air pressure on top of a newspaper provides enough leverage to sever a piece of wood. Who would've thought that? Not me!