首页
登录
职称英语
The mystery of the expansion of sea ice around Antarctica, at the same time
The mystery of the expansion of sea ice around Antarctica, at the same time
游客
2023-11-06
63
管理
问题
The mystery of the expansion of sea ice around Antarctica, at the same time as global warming is melting swaths of Arctic sea ice, has been solved using data from US military satellites.
Two decades of measurements show that changing wind patterns around Antarctica have caused a small increase in sea ice, the result of cold winds off the continent blowing ice away from the coastline.
" Until now these changes in ice drift were only speculated upon using computer models, " said Paul Holland at the British Antarctic Survey. "Our study of direct satellite observations shows the complexity of climate change.
" The Arctic is losing sea ice five times faster than the Antarctic is gaining it, so, on average, the Earth is losing sea ice very quickly. There is no inconsistency between our results and global warming. "
The extent of sea ice is of global importance because the bright ice reflects sunlight far more than the ocean, meaning temperature rises still further.
This summer saw a record low in Arctic sea ice since satellite measurements began 30 years ago. Holland said the changing pattern of sea ice at both poles would also affect global ocean circulation, with unknown effects. He noted that while Antarctic sea ice was growing, the Antarctic ice cap—the glacier and snow pack on the continent—was losing mass, with the fresh water flowing into the ocean.
The research on Antarctic sea ice, published in Nature Geoscience, revealed large regional variations. In places where warm winds blowing from the tropics towards Antarctica had become stronger, sea ice was being lost rapidly. "In some areas, such as the Bellingshausen Sea, the sea ice is being lost as fast as in the Arctic, " said Holland.
But in other areas, sea ice was being added as sea water left behind ice being blown away from the coast froze. The net effect is that there has been an extra 17, 000 sq km of sea ice each year since 1978—about a tenth of a percent of the maximum sea ice cover.
Antarctica is a continent surrounded by an ocean, whereas the Arctic is an ocean surrounded by a continent. For that reason, said Holland, sea ice was not able to expand by the same mechanism in the Arctic as at the southern pole, because if winds pushed the ice away from the pole it quickly hit land.
Holland did the research with Ron Kwok at Nasa’s jet propulsion laboratory in California, where maps of sea ice movements were created from more than 5 m individual daily measurements collected over 19 years. The maps showed, for the first time, the long-term changes in sea ice drift around Antarctica.
Kwok said; "The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent. " [br] The maximum sea ice cover is about______.
选项
A、17, 000 sq km
B、170, 000 sq km
C、1, 700, 000 sq km
D、17, 000, 000 sq km
答案
D
解析
推理题。文章第八段最后一句提到从1978年开始,每年都额外增加1.7万平方公里的海冰——这大约是海冰覆盖最大面积的千分之一,由此推出海冰覆盖最大面积是1700万平方公里,所以[D]为正确答案。
转载请注明原文地址:http://tihaiku.com/zcyy/3162840.html
相关试题推荐
WhileAustraliansareawareoftheexpansionofconventionalgasoutputint
WhileAustraliansareawareoftheexpansionofconventionalgasoutputint
WhileAustraliansareawareoftheexpansionofconventionalgasoutputint
ThemysteryoftheexpansionofseaicearoundAntarctica,atthesametime
ThemysteryoftheexpansionofseaicearoundAntarctica,atthesametime
ThemysteryoftheexpansionofseaicearoundAntarctica,atthesametime
Whatcanweinferaboutthecompany?[br][originaltext]W:Aftertheexpansion
Whatisthenewitemmainlyabout?[br][originaltext]Authoritiesaroundth
Whatisthenewitemmainlyabout?[originaltext]AuthoritiesaroundtheGulf
Whatisthenewitemmainlyabout?[originaltext]Well,movingaroundtothe
随机试题
[originaltext]Whattypeofmusicisthis?(A)Ididn’tfindanymistakes.(B)
Youshouldspendabout20minutesonthistask.Thetwomapsbelowshowroadacc
期货合约中的唯一变量是()。A、数量B、价格C、质量D、交割月份B在合约中,标的物的数量、规格、交割时间和地点等都是既定的。期货价格在交易所以
报警隔离球阀未打开也会造成预作用自动喷水灭火系统压力表读数不在正常范围。
有关高血压病人术前评估和准备哪项正确A.术前一天应停用所有抗高血压药 B.麻醉
患者男,1周前行左上牙槽神经阻滞麻醉下拔除,4天前出现左侧面部深处疼痛,张口困难
若以p表示价格,q表示数量,则派氏物量指数的计算公式为( )。
反映体内贮存铁量的指标()A.血清铁饱和度 B.总铁结合力 C.血清铁
根据《生活垃圾卫生填埋处理技术规范》(GB50869—2013),下列关于生活
甲状腺功能亢进症最常见于A.碘甲亢 B.毒性弥漫性甲状腺肿 C.甲状腺炎伴甲
最新回复
(
0
)