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Meteorology and the Triple Jump

If you've ever looked at the results of Olympic Triple Jump, you've probably noticed that right beside the athlete's "mark" (jump distance) is the wind as measured at the time of the jump:

The natural assumption to make is that, of course, wind must affect how far the athlete's are able to jump.  In track lingo jumps with a tailwind are referred to as "wind-assisted" and most track records set limits on how much tailwind can be present in order for the record to be official.  But how much does the wind matter?

To investigate, I looked up this morning's Women's Triple Jump qualifiers and did some quick analysis that modeled the athlete and the wind:

That's a pretty good model - most jumps are around 13-14 meters so a standard error of 0.2 meters is fairly small.  The coefficient on wind is 0.07570, so for every 1 meter/second increase in tailwind, you can expect a jump to be about .0757 meters further than the athlete would normally have jumped with no wind.  But what is the practical significance of that?

To see, I plotted the additional distance the silver and bronze medal winners from past Olympics would have needed to gain from the wind in order to match the gold medalist's distance, and included reference lines for wind speeds that would have been sufficient:

So from this we can see that having the wind 1 meter/second more advantageous would have put the last two silver medal winners into gold, and just over 2 meters/second would have moved the bronze medal winners into gold.  But how common are those wind speeds?  Here is a histogram of wind speeds from this morning's qualifiers:

So 1-2 meter/second shifts in wind speed are not unusual at all!  Here are the qualifying jumps from this year's competition, with gridlines representing the shift in any point for a 1 meter/second change in wind speed:

The finals of the competition will be Sunday at 2:35 pm Eastern US time or 7:35 pm local time in London.  When you watch, be sure to not just admire the incredible jumping ability these athletes possess but also keep an eye on the wind!

Comments

Name: Alex • Monday, August 6, 2012

Fascinating!


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