There Goes Your Roof
Whether it’s called a hurricane, a typhoon, or a tropical cyclone, this is one dangerous but awesome kamikaze (Japanese for “divine wind“). While tornadoes have stronger winds than a hurricane, they are relatively small and don’t last long. Hurricanes can be up to half the size of the contiguous United States, and they maintain their peak intensity for days at a time. Besides flooding rains, they also bring the sea ashore with them, battering the land with a surge of up to 6 meters (20 ft) high, topped with waves of up to 15 meters (50 ft) tall.
Everybody in the path of these storms should know and follow hurricane safety tips. Then, after you’ve taken the right steps to protect your property and life, and while you’re waiting out the storm, you can check out some of the many fascinating facts about hurricanes.
For instance, did you know that . . .
10 Hurricanes Contain Lots Of Snow And Ice
Hurricanes run on heat, but hurricane clouds tower many kilometers into the sky, up through the troposphere (where most of Earth’s weather happens). Major hurricanes have “hot towers” that can reach the stratosphere. It’s cold up there, around –51 degrees Celsius (–60 °F), so all that upper hurricane moisture turns to ice and snow. If you have ever been in a hurricane, you know that the sky gets hazy about a day before the stormy weather sets in. That haziness is due to cirrus clouds that are part of the hurricane’s outflow, and they are made of ice crystals. These cirrus clouds also show up beautifully in satellite pictures.
Eventually, most of that frozen stuff plummets out of the high clouds and melts again. However, some of it continues upward. Recent research shows that this ice ejected into the stratosphere from hurricanes may contribute to global warming. “Cirrus outflow” is just a technical way of saying the hurricane is exhaling, because . . .
9 Hurricanes Breathe, And Their Eyes ‘Blink’
A hurricane breathes in at the ocean surface. This air would flow straight in if it weren’t for the Coriolis effect, which deflects the air counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. The Coriolis effect also prevents the inflow from reaching the center of low pressure. Instead, all that violent wind is forced to circle the center and rise, forming the eyewall.
The inflow rushes up tens of thousands of meters and then spirals outward from the center as cirrus outflow. This icy exhalation moves in the opposite direction to the one at the surface. Meanwhile, some of the rising air doesn’t make it out of the hurricane. Instead, it slows down and sinks back toward the surface, drying out and losing its clouds in the process. This clear central eye region is the calmest place in the storm. However, things can change quickly. Major hurricanes tend to have eyewall replacement cycles, during which the eye shrinks in size. It “blinks” (fills in with clouds) and then opens up again as a new eyewall forms.
8 Hurricanes Register On Seismographs
Water is heavy. An ordinary ocean wave contains many liters of water, and the giant waves of a hurricane surpass all others in terms of size and weight. In a hurricane, waves are moving fast, with a lot of momentum. As a result of this, they pound land with incredible power, making the Earth shake. The giant waves can also collide far from shore, like Jaegers and Kaiju in Pacific Rim, causing low-frequency sound waves.
When scientists first noticed these seismic waves in the 1900s, they thought it was just background noise. It wasn’t until the middle of the 20th century that they realized hurricanes were causing these seismic and infrasound signals. Back in 1938, signals from a category five hurricane that struck the East Coast showed up on seismographs in Sitka, Alaska. Modern seismometers are extremely sensitive, so it’s not surprising that Superstorm Sandy, for example, set off seismic arrays across the United States. Scientists have also used seismometers to track air pressure changes in a hurricane.
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