No horses were harmed writing this blog.... Among old salty men of the sea there is a tale about the "horse latitudes". Legend says that in the days of old sailing ships, horses were transported across the oceans. About 30 degrees north and south of the equator is a ridge of high pressure that comes vertically down upon the area causing the winds to stop blowing and the sea is like glass. Ships would get stuck in this place that is without wind and drift in the ocean currents until they were out of this high pressure area. This could take days or months! Water would run out, the live cargo (the horses!) needed water and so did the salty old sea men, so they would throw the horses overboard to conserve water. Whether this legend is true or not is questionable, but the name stuck and on almost every map ever made is the label "horse latitudes" at 30 degrees north and south of the equator. So I get how sad it is that these crusty crabs had to throw horses over board to save their lives, but what is up with the part, "the winds flow vertically downward creating high pressure"... Using this diagram helps a little. At the equator the air is warm and lifts or rises upwards creating a low pressure zone (heated, excited and expanded air particles). As the air mass cools over the 30 degree north latitude the gases sink creating a high pressure zone (cold, closely packed gases) that is made of dry, cold air. To understand this model we have to understand that air masses convect in the atmosphere. The heat source of course is our Sun. What if we want to see what it looks like at the horse latitudes? Oh look! Here's a picture! That is a calm ocean...compared to the normal seas... What about a satellite image? Could we see what cloud formation looks like on Earth from space? Well, there we go. Cloud formations at the equator. Just like they said...and then what happens? Because the Earth isn't heated equally everywhere on its surface, warm air masses (high pressure) mixes with cold air masses (low pressure). This mixing of air pressure creates winds that blow certain directions depending on latitude. The trade winds are found between 0 and 30 degrees north and south of equator. Scientists have shown that these winds are very predictable all year long. Between 30 to 60 degrees latitude both north and south latitudes have winds called "westerlies". These winds are not as predictable but continue to drive ocean currents toward the poles. What if there wasn't any wind on the planet? Could we survive? To get rid of wind we would need to heat the planet equally on every square foot land and sea. To do that the Earth can't be round, it would have to be hammered perfectly flat..no mountains, no hills, all flat. So the answer to that question would we survive? No. Get used to the wind! Wind is good! Alrighty! Keep the wind!
13 Comments
|
Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |