东非将持续干旱
文章来源:未知 文章作者:enread 发布时间:2011-01-30 02:11 字体: [ ]  进入论坛
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The increased frequency of drought observed in Eastern Africa over the last 20 years is likely to continue as long as global temperatures continue to rise, according to UC Santa Barbara scientist Park Williams. The new research, published in Climate Dynamics1, indicates that more drought poses increased risk to millions of people in Kenya, Ethiopia, and Somalia, who currently face potential food shortages.

"Forecasting precipitation(沉淀,冰雹) variability from year to year is difficult, and research on the links between global change and precipitation in specific regions is ongoing2 so that more accurate projections3 of future precipitation can be developed," said Williams, first author and postdoctoral fellow in the Department of Geography.

Warming of the Indian Ocean, which causes decreased rainfall in eastern Africa, is linked to global warming. These new projections of continued drought contradict(反驳,否定) scenarios4 previously5 projected by the Intergovernmental Panel on Climate Change which predict increased rainfall in Eastern Africa.

This new research supports efforts by the USGS and the U.S. Agency for International Development to identify areas of potential drought and famine(饥荒) in order to target food aid and help inform agricultural development, environmental conservation, and water resources planning.

"Global temperatures are predicted to continue increasing, and we anticipate that average precipitation totals in Kenya and Ethiopia will continue decreasing or remain below the historical average," said co-author Chris Funk, USGS scientist. "The decreased rainfall in Eastern Africa is most pronounced(显著的,断然的) in the March to June season, when substantial rainfall usually occurs. Although drought is one reason for food shortages, it is exacerbated6(加重,恶化) by stagnating7 agricultural development and continued population growth."

As the globe has warmed over the last century, the Indian Ocean has warmed especially fast. The resulting warmer air and increased humidity over the Indian Ocean produce more frequent rainfall in that region. The air then rises, loses its moisture(水分,湿度) during rainfall, flows westward8, and descends9 over Africa, causing drought conditions in Ethiopia and Kenya.

Williams explained that it is also important to note that while sea-surface temperatures are expected to continue to increase in the Indian Ocean, causing an average decrease in rainfall in Eastern Africa, there will still be very wet years due to the many factors that influence precipitation.

The scientists compiled existing datasets on temperature, wind speed, and precipitation to see what was driving climate variations in the tropical Indian and Pacific Ocean region. Most of the Indian Ocean warming is linked to human activities, particularly greenhouse gas and aerosol10 emissions11. The Indian Ocean has warmed especially fast because it is quickly being encroached(侵占) upon by the Tropical Warm Pool, an area with the warmest ocean surface temperatures anywhere.

This research supports efforts by the USGS and the U.S. Agency for International Development, through the Famine Early Warning Systems Network. FEWS NET is a decision support system that helps target more than $2 billion of food aid to more than 40 countries each year. Through this system, scientists are helping12 with early identification of agricultural drought that might trigger food insecurity.



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1 dynamics NuSzQq     
n.力学,动力学,动力,原动力;动态
参考例句:
  • In order to succeed,you must master complicated knowledge of dynamics.要取得胜利,你必须掌握很复杂的动力学知识。
  • Dynamics is a discipline that cannot be mastered without extensive practice.动力学是一门不做大量习题就不能掌握的学科。
2 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。
3 projections 7275a1e8ba6325ecfc03ebb61a4b9192     
预测( projection的名词复数 ); 投影; 投掷; 突起物
参考例句:
  • Their sales projections are a total thumbsuck. 他们的销售量预测纯属估计。
  • The council has revised its projections of funding requirements upwards. 地方议会调高了对资金需求的预测。
4 scenarios f7c7eeee199dc0ef47fe322cc223be88     
n.[意]情节;剧本;事态;脚本
参考例句:
  • Further, graphite cores may be safer than non-graphite cores under some accident scenarios. 再者,根据一些事故解说,石墨堆芯可比非石墨堆芯更安全一些。 来自英汉非文学 - 环境法 - 环境法
  • Again, scenarios should make it clear which modes are acceptable to users in various contexts. 同样,我们可以运用场景剧本来搞清楚在不同情境下哪些模式可被用户接受。 来自About Face 3交互设计精髓
5 previously bkzzzC     
adv.以前,先前(地)
参考例句:
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
6 exacerbated 93c37be5dc6e60a8bbd0f2eab618d2eb     
v.使恶化,使加重( exacerbate的过去式和过去分词 )
参考例句:
  • The symptoms may be exacerbated by certain drugs. 这些症状可能会因为某些药物而加重。
  • The drugs they gave her only exacerbated the pain. 他们给她吃的药只是加重了她的痛楚。 来自《简明英汉词典》
7 stagnating 46c4025763e21f3b32abe0666497a0da     
v.停滞,不流动,不发展( stagnate的现在分词 )
参考例句:
  • I feel I'm stagnating in this job. 我觉得,干这份工作我没有长进。
  • ITT was stagnating when Geneen became the chief executive officer in 1959. 1959年吉宁出任行政总负责人时,国际电话电报公司正处于不景气时期。 来自辞典例句
8 westward XIvyz     
n.西方,西部;adj.西方的,向西的;adv.向西
参考例句:
  • We live on the westward slope of the hill.我们住在这座山的西山坡。
  • Explore westward or wherever.向西或到什么别的地方去勘探。
9 descends e9fd61c3161a390a0db3b45b3a992bee     
v.下来( descend的第三人称单数 );下去;下降;下斜
参考例句:
  • This festival descends from a religious rite. 这个节日起源于宗教仪式。 来自《简明英汉词典》
  • The path descends steeply to the village. 小路陡直而下直到村子。 来自《简明英汉词典》
10 aerosol WfAyF     
n.悬浮尘粒,气溶胶,烟雾剂,喷雾器
参考例句:
  • They sprayed aerosol insect repellent into the faces of police.他们将喷雾驱虫剂喷在了警察的脸上。
  • Aerosol particles affect visibility,climate,and our health and quality of life.气溶胶对大气能见度、气候变化以及人类健康等有重要影响。
11 emissions 1a87f8769eb755734e056efecb5e2da9     
排放物( emission的名词复数 ); 散发物(尤指气体)
参考例句:
  • Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
  • Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。
12 helping 2rGzDc     
n.食物的一份&adj.帮助人的,辅助的
参考例句:
  • The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
  • By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。
TAG标签: global drought Africa
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