Weather class visit

The reason for seasons


ORANGE PARK, Fla. – Our atmosphere hides the fact that we are rotating around the Earth's axis at 1000 mph. School children are always curious about the weather. One of the questions they ask is why don't we feel the spin.

Meteorologist Mark Collins started with the basics for Pre-K students at St. Johns Country Day School. The reason for seasons made a perfect introduction to weather.

Collins, speaking to the Clay county school said, "If the Earth stopped rotating the atmosphere would stay in motion blasting us with nearly 1000 mph winds. We don't feel the rush of wind because our atmosphere travels at the same rate."

Everyone is surprised to discover Earth days lasted less than 4 hours. This was before a Mars sized proto-planet crashed into Earth producing the moon.  Since then the planet continues to spin slower making our days longer. Ocean tides slosh across the basins with the friction acting like a break on rotation. 

This isn't anything to lose sleep over. The slowdown is less than a blink of the eye or about 1.7 milliseconds every century. 

Floridians may not notice a change in season but they would never occur if the the axis of rotation wasn't tilted. Earth's spinning axis is tilted 23.5° providing moderate seasons and preventing temperature extremes anywhere on the planet.

In contrast, Mercury is not tilted and produces drastic temperature differences across the planet. Life is impossible with drastic heat at the equator to ice at the poles. 

As our planet travels around the sun the north pole is tilted toward it and the day lasts longer in the summer north of the equator. This results in warmer average temperatures. By wintertime the north pole is tilted away from the Sun, the reverse is true and the weather is generally cooler. 

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