流入海洋的淡水在逐年增加
文章来源:未知 文章作者:meng 发布时间:2010-10-06 03:26 字体: [ ]  进入论坛
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Freshwater is flowing into Earth's oceans in greater amounts every year, a team of researchers has found, thanks to more frequent and extreme storms linked to global warming. All told, 18 percent more water fed into the world's oceans from rivers and melting polar ice sheets in 2006 than in 1994, with an average annual rise of 1.5 percent. "That might not sound like much – 1.5 percent a year – but after a few decades, it's huge," said Jay Famiglietti, UC Irvine Earth system science professor and principal investigator1 on the study, which will be published this week in Proceedings2 of the National Academy of Sciences. He noted3 that while freshwater is essential to humans and ecosystems4, the rain is falling in all the wrong places, for all the wrong reasons.

"In general, more water is good," Famiglietti said. "But here's the problem: Not everybody is getting more rainfall, and those who are may not need it. What we're seeing is exactly what the Intergovernmental Panel on Climate Change predicted – that precipitation is increasing in the tropics and the Arctic Circle with heavier, more punishing storms. Meanwhile, hundreds of millions of people live in semiarid5(半干旱的) regions, and those are drying up."

In essence, he said, the evaporation6(蒸发,消失) and precipitation(沉淀,坠落) cycle taught in grade school is accelerating dangerously because of greenhouse gas-fueled higher temperatures, triggering monsoons7(季风,雨季) and hurricanes. Hotter weather above the oceans causes freshwater to evaporate faster, which leads to thicker clouds unleashing8(发动,解除) more powerful storms over land. The rainfall then travels via rivers to the sea in ever-larger amounts, and the cycle begins again.

The pioneering study, which is ongoing9, employs NASA and other world-scale satellite observations rather than computer models to track total water volume each month flowing from the continents into the oceans.

"Many scientists and models have suggested that if the water cycle is intensifying10 because of climate change, then we should be seeing increasing river flow. Unfortunately, there is no global discharge measurement network, so we have not been able to tell," wrote Famiglietti and lead author Tajdarul Syed of the Indian School of Mines, formerly11 of UCI.

"This paper uses satellite records of sea level rise, precipitation and evaporation to put together a unique 13-year record – the longest and first of its kind. The trends were all the same: increased evaporation from the ocean that led to increased precipitation on land and more flow back into the ocean."

The researchers cautioned that although they had analyzed12 more than a decade of data, it was still a relatively13 short time frame. Natural ups and downs that appear in climate data make detecting long-term trends challenging. Further study is needed, they said, and is under way.



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1 investigator zRQzo     
n.研究者,调查者,审查者
参考例句:
  • He was a special investigator for the FBI.他是联邦调查局的特别调查员。
  • The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。
2 proceedings Wk2zvX     
n.进程,过程,议程;诉讼(程序);公报
参考例句:
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
3 noted 5n4zXc     
adj.著名的,知名的
参考例句:
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
4 ecosystems 94cb0e40a815bea1157ac8aab9a5380d     
n.生态系统( ecosystem的名词复数 )
参考例句:
  • There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
  • Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样,从雨林到半荒漠等不一而足。 来自辞典例句
5 semiarid oiozuX     
adj.雨量非常少的,半干旱的
参考例句:
  • The region is semiarid to arid in overall climate.这个地区总体上是半干旱至干旱气候。
  • In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge,usually because of a lack of moisture.在很多半干旱地带也有下层的树带界限,在这种环境中,由于缺乏水分,森林下缘逐渐变成干草原或者是沙漠。
6 evaporation Pnoxc     
n.蒸发,消失
参考例句:
  • Be careful not to lose too much liquid by evaporation.小心不要因蒸发失去太多水分。
  • Our bodies can sweat,thereby losing heat by evaporation.我们的身体能出汗,由此可以蒸发散热。
7 monsoons 49fbaf0154b5cc6509d1ad6ed488f7d5     
n.(南亚、尤指印度洋的)季风( monsoon的名词复数 );(与季风相伴的)雨季;(南亚地区的)雨季
参考例句:
  • In Ban-gladesh, the monsoons have started. 在孟加拉,雨季已经开始了。 来自辞典例句
  • The coastline significantly influences the monsoons in two other respects. 海岸线在另外两个方面大大地影响季风。 来自辞典例句
8 unleashing 8742c1b567c83ec8d9e14c8aeacbc729     
v.把(感情、力量等)释放出来,发泄( unleash的现在分词 )
参考例句:
  • Company logos: making people's life better by unleashing Cummins power. 公司理念:以康明斯动力建设更美好的生活! 来自互联网
  • Sooner or later the dam will burst, unleashing catastrophic destruction. 否则堤坝将崩溃,酿成灾难。 来自互联网
9 ongoing 6RvzT     
adj.进行中的,前进的
参考例句:
  • The problem is ongoing.这个问题尚未解决。
  • The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。
10 intensifying 6af105724a108def30288b810d78b276     
v.(使)增强, (使)加剧( intensify的现在分词 );增辉
参考例句:
  • The allies are intensifying their air campaign. 联军部队正加大他们的空战强度。 来自辞典例句
  • The rest of the European powers were in a state of intensifying congestion. 其余的欧洲强国则处于越来越拥挤的状态。 来自英汉非文学 - 历史
11 formerly ni3x9     
adv.从前,以前
参考例句:
  • We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
  • This boat was formerly used on the rivers of China.这船从前航行在中国内河里。
12 analyzed 483f1acae53789fbee273a644fdcda80     
v.分析( analyze的过去式和过去分词 );分解;解释;对…进行心理分析
参考例句:
  • The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
  • The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程,因为对他来说,爱是个不可分析的迷。 来自《简明英汉词典》
13 relatively bkqzS3     
adv.比较...地,相对地
参考例句:
  • The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
  • The operation was relatively painless.手术相对来说不痛。
TAG标签: water global oceans
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