Earth has storms. Some to us, appear massive and can cause millions of dollars’ worth
of damage. In the grand scheme of things though, they’re not that big. Compared to the biggest
storm we know about, that of the Red Spot on Jupiter, they’re pretty tiny. But for
us mere mortals we need to understand these storms in order to protect people and property
as best as we can. Right now we’re going to look a notorious hotspot for cyclones,
the Bay of Bengal near India, and at cyclone Phailin that ran its course from the 8th-14th
of October 2013. The cyclone started off as a depression, but
very rapidly intensified over the course of two days. By the tenth of October it had properly
become a very severe cyclonic storm, equal to a category 1 hurriance. The next day, it
became a category 5 hurricane, and the second strongest system to ever make landfall in
India. But because of frictional forces over land, by the 12th it started to weaken, and
the 13th and 14th shows it returning again to an area of low pressure.
If we zoom out a bit, I find it very interesting that while this is going on, there seem to
be other cyclonic systems going on over the pacific. This typhoon season was the most
active and most destructive for many years, as you can see by the amount that’s happening
over such a short period of time. The first typhoon you can see is the category 3 Typhoon
Nari (Santi). It began over the Philippines and made its way over to Vietnam before fizzling
out. The next typhoon you see is Typhoon Wipha (Tino). It got a strong as a category 4 typhoon.
And lastly, I thought you might find it interesting to see what the whole Earth looks like during
this time. It is a beautiful planet, and visually it is my favourite.
You might also be wondering what the difference is between typhoons, cyclones and hurricanes
and also how they are formed. The short version is that tropical cyclones in the west Pacific
and are called Typhoons, those in the Indian Ocean are cyclones and those in the Atlantic
and east Pacific Ocean are called Hurricanes. It's the longitude that makes the difference.
When in the northern hemisphere they will all spin anti or counter clockwise, and in
the southern hemisphere they will spin clockwise. And how they form? Tropical cyclones are like
giant engines that use warm, moist air as fuel. That is why they form only over warm
ocean waters near the equator. The warm, moist air over the ocean rises upward from near
the surface. Because this air moves up and away from the surface, there is less air left
near the surface. Air from surrounding areas with higher air
pressure pushes in to the low pressure area. Then that "new" air becomes warm and moist
and rises, too. As the warm air continues to rise, the surrounding air swirls in to
take its place. As the warmed, moist air rises and cools off, the water in the air forms
clouds. The whole system of clouds and wind spins and grows, fed by the ocean's heat and
water evaporating from the surface. Because the Pacific is so warm, it’s this ocean
that will see the most tropical cyclones.