What is Seasons?

Winter, spring, summer, fall--most students can name the seasons, but few can correctly explain why there are seasons.  Static diagrams in textbooks, classroom demonstrations (such as shining flashlights on globes) and videos can do only so much.  What if the student could actually create seasons by manipulating the Earth itself?  What if they could learn by doing rather than watching?  Seasons is designed with just these capabilities in mind; Seasons is an easy-to-use "what if" program for learning about...seasons!

Using Seasons, you and your students will be able to:

	View yearly cycles of temperature, daily solar energy, hours of daylight, and Sun elevation.  Students can watch vivid graphical depictions showing the progression of the seasons in terms of these important factors.
	Change the seasons by changing the Earth's axis tilt and the shape of its orbit. The tilt of the Earth's axis is responsible for seasons on Earth; changing the tilt leads directly to changes in the amplitude of the seasonal changes in temperature. Orbits that are far from round have effects that only somewhat resemble the seasons on Earth.  Your students will quickly learn that eccentric orbits cause seasons that differ from their knowledge of what seasons should be like, helping to dispel the common misconception that the Sun's varying distance causes seasons.
	Make use of interactive explanation screens to explore the concepts underlying what they see happening on the Model Display screen.  Version 2 of Seasons greatly enhances these, making use of 3D graphics to help convey the many concepts that provide the foundation of understanding how seasons work.
	Save their Earth configurations and comments about them in files you can assess.  The Seasons Logbook allows students to reuse saved configurations, print out tables and charts summarizing their seasons, and even export the season model's data to spreadsheets.

Sample Screens

Click on the pictures for enlarged views of the screens and use your browser's Back button to return.  Note that the enlarged views are smaller than the screens would appear in reality, and that the image quality is therefore a bit degraded.

	This is Seasons' Main Screen, on which you can see the Earth moving around the Sun.  The Earth's colors are used to indicate the current temperature at different latitudes.  You can also show how daily solar energy, hours of daylight, and noon Sun elevation depend on latitude and season.  The smaller charts show the Earth's orbit, different views of the Earth, and a graph of the selected variable at one or two latitudes.  You can even compare the graphs of consecutive runs to show the changes from one configuration to another.
	Changing the Earth's tilt is as easy as clicking and dragging the Earth's North Pole.  For finer precision, use the slider or type in the exact tilt you'd like to use.  The bottom left button conveniently sets the tilt to the "Earth Normal" value of 23.5°.  The buttons at right take you to related interactive dialogs, examples of which are shown below.
	If you've done the classic flashlight-on-the-globe demonstration, you'll appreciate this interactive.  In it, a sunbeam of fixed cross-section strikes the Earth, illuminating an oval with area that depends on latitude.  Sliding the beam north and south in latitude really shows clearly how sunlight is concentrated differently.  You can also change the season to see how that affects the sunlight.  And of course, since this is in 3D, you can tilt and rotate the Earth to get just the right view of what's happening.
	If you want to see how the Sun's elevation changes during the year, use this interactive.  The view can be tilted and rotated easily to show what's happening from any perspective.  You can also change the Earth's tilt and the latitude to see how some places get a great amount of nearly overhead sunlight, while other places never see the Sun much above the horizon.
	Learning why some days are short and others are long is crystal clear with this interactive.  Look at the winter solstice Earth on the left, and observe how little of the latitude band is in sunlight.  As the Earth spins, any point on that band isn't going to be in sunlight for long.  Compare that to the summer solstice case at right, where most of the band is in the sunlight; the day's going to be much longer in this case.  And to help make this more interesting, of course you can change the Earth's tilt and the latitude to see what that might do!
	The Logbook lets you see all four graphs at once, and more.  Your students can write comments about their model results and save them to files for you to assess.  The Logbook also provides printouts of monthly values, and you can export a year's worth of daily data in either text or CSV format for use in spreadsheets.

If you'd like to see more sample screens, write us at support@riversci.com or download the demo program.

System Requirements

Seasons has the following minimum requirements:

• Windows 95/98/ME/2000/XP or Mac OS 10.3+.  Windows 95 must be Service Release 2 or later.
  Seasons runs on both PowerPC and Intel Macs.
• A processor speed of 500MHz or faster; 1 GHz or faster is preferred
• Approximately 12 MBytes of free hard disk space
• A screen resolution of at least 800x600 pixels with 16-bit color (SVGA mode); 1024x768 pixels with 24- or 32-bit color (XGA mode) is preferred
• Graphics adapter that supports 3D graphics hardware acceleration.  This is standard on most computers
• A CD-ROM drive (required for installation)
• Mouse or other compatible pointing device
• Printer capability is required if you wish to print out logbook entries

Almost all PCs sold during the past several years meet these requirements. We suggest that you download the trial version if you would like to verify your system's ability to run Seasons.

Teacher's Guide

The Teacher's Guide for Seasons is a PDF file than can be read with Adobe Acrobat.  The version available here omits the answers to the questions posed within it; the Teacher's Guide you receive with the software will contain the answers.

Clicking on the link below will open the Teacher's Guide for viewing (if your browser is so configured).  To save the file, right click on the link and choose the Save Target As... option.

Seasons Teacher's Guide