2012年10月31日 星期三

Did global warming cause Hurricane Sandy?

Naturally, a warmer climate would affect how weather systems behave. The tricky question is how? Generally, a warmer climate would probably make storms more frequent and powerful and wetter than they’ve been in the past. But which storms would get worse, and when? Scientists are struggling to answer that question.

Andy Nash, the head meteorologist at the National Weather Service in South Burlington, suggests thinking about how climate change affects weather by imagining an unethical Major League Baseball home run slugger.

Bill already hits a ton of home runs each season, but he wants to hit even more. So he takes steroids and the number of home runs he hits increases as a result. Once Bill is on steroids, it’s impossible to tell how many of the home runs are because of the steroids, and how many would have happened anyway.

Nash said global warming is essentially weather on steroids. There’s more of it, and more extremes due to climate change, but it’s hard to tell which storms were made possible through global warming, and which storms would have happened regardless.

A lot of factors went into creating the monster that was Hurricane Sandy. Most of those factors are routine occurences that happen with weather systems all the time. It started with a hurricane forming south of Jamaica and moving north. The area south of Jamaica is a prime breeding ground for hurricanes in late October, so it wasn’t odd that one would form there.

Meanwhile,Directory ofchina glass mosaic Tile Manufacturers, a winter like storm crossed from the Pacific and started heading eastward across the United States. Again, that’s not unusual. We often start getting that type of storm system this time of year.

Thirdly, a topsy-turvy weather pattern called a block in the Atlantic Ocean was preventing weather systems from moving generally east to west across the ocean like they usually do. The blocking weather pattern is somewhat unusual, but definitely not unheard of.

Hurricane Sandy, heading north from Jamaica, would have normally been steered northeastward, out to sea off the East Coast by the winter like storm coming in from the west. But Sandy couldn’t do that, thanks to the blocking weather pattern gumming up the works over the Atlantic.

The storm from the west was also pretty much stopped in its eastward march by the North Atlantic block. So it stalled, sort of tilted backwards, and drew Sandy northwestward into the East Coast.

So what does all that have to do with global warming? Well, we’re now back to Slugger Bill and his steroid addiction. Like Bill’s extra home runs, it’s hard to tell if Sandy would have happened anyway, or if global warming made the monster storm possible.

There are intriguing pieces of evidence and theory – call them steroid injections – that global climate change might have made Sandy more of a powerhouse than she otherwise might have been.

For one, let’s talk about that block over the Atlantic. The block is a natural occurence that would happen with or without climate change. However, as some climate scientists like Jennifer Francis of Rutgers University point out, Arctic sea ice due to global warming slows the jet stream, making Atlantic blocks more frequent and stronger.

The extent of Arctic sea ice near the North Pole hit a record low in September.

“While it’s impossible to say how this scenario might have unfolded if sea-ice had been as extensive as it was in the 1980s, the situation at hand is completely consistent with what I’d expect to see happen more often as a result of unabated warming and especially the amplification of that warming in the Arctic,” Francis wrote, as reported by Justin Gillis in the New York Times.

So it’s possible global warming might have influenced the formation of the block and steered Sandy. We’ll probably never know for sure.

Water temperatures off the U.S. East Coast were warmer than normal when Sandy entered the picture. The warmer the water, the more energy and strength a hurricane can draw from the ocean.

Water temperatures have been generally increasing off the East Coast over the years, many believe because of global warming.Posts with indoor tracking system on TRX Systems develops systems that locate and track personnel indoors. So did the warm water strengthen Sandy beyond what it otherwise would have achieved? Again, possibly, but nobody can be sure.A stone mosaic stands at the spot of assasination of the late Indian prime minister.

Sea levels have risen a bit as ice from glaciers melted. That might have helped make the storm surges a little higher along the coast than they otherwise would have, but it probably only would have made a slight difference.

Some climate scientists are becoming more direct at linking storms like Sandy to climate change. Most of them agree storms and other extreme weather events like droughts and heat waves are becoming more frequent due to climate change. A lot of these scientists regard Sandy as a symptom.

For instance, Scientific American on Tuesday quoted this representative Tweet from Jonathan Foley, director of the Institute on the Environment at the University of Minnesota: “Would this kind of storm happen without climate change? Yes. Fueled by many factors. Is [the] storm stronger because of climate change? Yes.”

The bottom line is global climate change might have been a factor in helping create Hurricane Sandy,We are pleased to offer the following list of professional mold maker and casters. and that we should generally expect more storms, and more weather extremes in the coming years.

Every time I mention climate change in this blog, I get a mini-storm of anger from some people saying that I’m lying, that global climate change does not exist,If you want to read about buy mosaic in a non superficial way that's the perfect book. and I’m alarmist.

All I can do as a journalist who does not have a PhD in climatology is find the best information from the best sources, and pass it along.

What I’ve found so far is a remarkable consensus among climatologists that the world is warming, that there are compelling but not always proven theories as to the practical effects of this warming, and a strong desire among those scientists to better understand how climate change will affect us here in the real world.

No doubt some of these scientists will look at Hurricane Sandy and try to figure out whether tragedies such as this are part of our future with climate change, or just a terribly sad fluke that might never happen again.

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