Ever wonder how much a cloud weighs? What about a hurricane? A meteorologist(气象学者) has done some estimates and the results might surprise you. Let's start with a very simple white puffy cloud — a cumulus cloud（积云）. How much does the water in a cumulus cloud weigh? Peggy LeMone, senior scientist at the National Center for Atmospheric Research in Boulder, Colorado, did the numbers. "The water in the little cloud weighs about 550 tons," she calculates. "Or if you want to convert it to something that might be a little more meaningful … think of elephants." The thought of a hundred elephants-worth of water suspended(悬浮的) in the sky begs another question — what keeps it up there? "First of all, the water isn't in elephant-sized particles（微粒）, it's in tiny tiny tiny particles," explains LeMone. And those particles float on the warmer air that's rising below. But still, the concept of so much water floating in the sky was surprising even to a meteorologist like LeMone. "I had no idea how much a cloud would weigh, actually, when I started the calculations," she says. So how many elephant units of water are inside a big storm cloud—10 times bigger all the way around than the "puffy" cumulus cloud? Again, LeMone did the numbers: About 200,000 elephants. Now, ratchet up(略微调高) the calculations for a hurricane about the size of Missouri and the figures get really massive(巨大的). "What we're doing is weighing the water in one cubic meter theoretically pulled from a cloud and then multiplying by(乘上) the number of meters in a whole hurricane," she explains. The result? Forty million elephants. That means the water in one hurricane weighs more than all the elephants on the planet. Perhaps even more than all the elephants that have ever lived on the planet. 小题1:The weight of is NOT mentioned in the passage.
|