Category: Weather (Page 3 of 3)

Weekend Science Fun: Dust Storms

This week let’s take a look at a weather phenomena that has been in the news in the Southwest:  dust storms.

On July 5, 2011 a huge dust storm hit Phoenix. It was a wall of rapidly blowing dust 5,000 feet high in some places.

This time-lapse video shows how it looked as the curtain of dust approached.

(In inside look at how the video was made.)

Dust storms occur most frequently in arid regions, such as the southwestern United States, the dry areas of Australia, the Middle East (see a similar dust storm that happened in April in Kuwait), China and the Sahara Desert. Here in Arizona we have them most frequently in the summer, typically in late June and July, although sometimes into September if the summer rains fail to materialize.

Why summer? The dust storms are fueled by the intense heat that causes air to rise, just like happens with thunderstorms. The rising updrafts eventually begin to cool when the air gets high enough and a rush of air starts down. Under certain conditions, the thunderstorms collapse and the down rushing air can be intense. Huge gusts of wind pick up any loose soil particles as they flow by. Where there are large areas of exposed soil -such as in deserts- the amounts of dust picked up can be extremely high.

Plants the day after the dust storm in Phoenix

To give you an idea what dust in the air was like during the recent storm, let’s take a look at the records from the weather stations that record the amount of particulates in the air. On a normal day, the average amount of particulates is 38 micrograms per cubic meter of air. On July 5th the readings ranged from 2,576 to 5,190 micrograms of particulate per cubic meter. (Source:  The Arizona Republic, July 24, 2011). That’s a lot of dust!

For some related hands-on activities, try the Wind Power post.

Weekend Science Fun: Phenology

Today let’s look at an opportunity to carry out a citizen science project, and look at some free science education resources from the Internet.

USA National Phenology Network is looking for citizen scientists to help them collect data.

What is phenology? It is the study of the timing of certain measurable events in the life cycles of living creatures. Examples might be time of migration or nesting in particular species of birds, date of flowering in certain plants, or mushroom formation in a certain type of fungus. The occurrence of these events is often related to climate. Spring is a great time to study phenology (in places with distinct seasons), because it is relatively easy to recognize key events, like when lilacs are flowering around your neighborhood.

Why is studying phenology important? Some events, such the the running of sugar maple sap, are significant for people who use it as a source of food. In one study from 1963 to 2003, researchers found the maple trees started running sap on average eight days earlier, which isn’t too much of a problem. The problem was that the trees started to bud (and stopped running the proper quality of sap) 11 days earlier, shortening the season by 10 percent. Other events may impact human health, such as when pollen sheds from certain allergenic plants. Interestingly, not all living things react in the same way to changes in temperature. Some events, particularly those later in the year, may actually be slowed.

In this somewhat long video, some of the members of the network explain what phenology is and how the network came about. Try watching the first part at least. It shows David Bertelsen climbing the same mountain in Arizona that he has climbed for the past 30 years. He diligently records information on some 600 species of plants that he encounters!

Look under “Participate” on the USA National Phenology Network website to learn how you can get involved through Nature’s Notebook.

Even if you aren’t interested in participating, go check out the Educator’s Clearinghouse! They have four pages of website links to free educational materials, lesson plans and activities to explore.

A sure sign of spring!

Inside Hurricanes

Our Weekend Science Fun is inspired by the book Inside Hurricanes by Mary Kay Carson. The book is reviewed is at Wrapped in Foil.

We were excited by the story of a unique dome-shaped beach home that survived when Hurricane Ivan hit Pensacola Beach, Florida in 2004. The owner had designed it so that winds blew around it and that storm surges could pass under. It turned out that the home with an interesting design passed the hurricane test. We decided to try out some of these ideas on our own.

Activity:  Does building shape influence level of damage by hurricane-force winds?

Gather:

  • computer paper
  • access to a computer and printer
  • tape or glue
  • scissors
  • hairdryer, to supply “hurricane winds”

First we will make structures of three different shapes:  rectangular, circular and a pyramid. (See photograph below.)

Pyramid

Go to PaperToys.com and print out the Great Pyramid pattern. Cut it out and assemble. Tape or glue tab.

Paper House – Rectangular

Start with a piece of computer paper.


(If you have difficulty seeing these instructions, let me know.)

Circular

Cut another sheet of computer paper roughly in half lengthwise. Lay both layers on top of one another (we’re trying to keep the weight of each house roughly the same). Bring the ends together to form a cylinder and tape or glue to hold.

Predict which of these shapes can withstand wind the best.

Find a flat surface that is near an electrical outlet, so you can plug in the hairdryer. Now place a penny or other marker on the flat surface. Rest one of the buildings on it. Plug in the hairdryer. If possible record how fast and/or how far the building travels when you blow the hairdryer on it. Try to stand a consistent distance from the building with the hairdryer. Repeat with the other buildings, making sure to place them on the same mark each time.

If you aren’t seeing any differences between the buildings, try lowering the setting on the hairdryer and/or standing farther away.

Extensions:  Try modifying the shape of the building, changing the weight of the paper you use to construct the buildings, or changing the speed of the hairdryer.

Photograph from NASA Images

Isn’t it fun when reading a book makes you want to try out something yourself?

More about Inside Hurricanes:

It is part of the Inside Series
Publisher: Sterling
Published: October 2010
Age range: from 8 to 12
48 pages (has 10 fold-out pages)
ISBN: 1-4027-7780-9
ISBN13: 9781402777806

This book was provided for review.

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