- 2014.06.17
괜찮은 독해하나 올려드립니당..
Ponds 'predict Arctic sea-ice melt'
A UK team believes it can now make skilful predictions of how much sea ice will melt during Arctic summers.
The scientists say the amount of water ponding on top of the floes as they warm in the spring has been shown to be an excellent indicator.
Using their technique, the Reading University researchers reckon the minimum ice extent this September will be about 5.4 million square km.
It is about the same as at the end of the melt season last year.
The floes in the far north are the subject of intense study currently because of their rapid summer decline.
Their extent has diminished from about 7 million square km in the 1990s to less than 5 million square km in five of the past seven years, with a record minimum of 3.6 million square km being set in 2012.
But the year-to-year variation is large and the computer models in general have failed to capture the behaviour.
Dark cover"The sort of three-month prediction we're making would be useful for people who need to do operations in the Arctic, such as shipping companies for navigation purposes," explained Prof Daniel Feltham, who leads the NERC Centre for Polar Observation and Modellingteam at Reading.
"But the physics we're introducing will also, hopefully, help improve the climate models that look longer term," he told BBC News.
Prof Feltham and colleagues have found a strong correlation between the fraction of the floes covered by pond water in May and the eventual sea-ice extent seen in September.
The physical link is the change in reflectiveness, or albedo, brought about by the standing water.
The ponds are darker than bare ice and therefore absorb more of the Sun's energy, promoting further melting.
Prof Feltham's team has developed a model to forecast the evolution of melt ponds in the Arctic and has incorporated this into more general climate sea-ice models.
Satellite records show that the year with smallest pond fraction in late spring (11% in 1996) had the biggest sea ice extent in September; and the year with the largest pond fraction (34% in 2012) featured the all-time low extent come the autumn.
The team published its ideas in a recent edition of the journal Nature Climate Change.
Southern differencesNow, it has put out its first open forecast for this September of 5.4 million square km, give or take half a million.
It compares with 5.35 million square km averaged across September last year.
"What could knock our prediction off course? Weather conditions, certainly. If we have anomalously cold conditions, we would expect the ice extent to be higher; or if we had very stormy conditions, like they did in August 2012 - that could diverge the ice and encourage more melting," he said.
In contrast to the Arctic, the Antarctic is currently showing an alternative trend, with the winter maximum extent growing to record levels.
How useful the Reading technique would be in predicting the region's summer minimums is uncertain.
The factors that control the floes in the south are different to those in the north, and already they diminish to very low extents by autumn as a matter of course anyway.
A New Zealand-led team recently demonstrated that the choppiness of Southern Ocean water could have a moderating impact on the growth of sea ice around Antarctica.
The Reading number has been submitted to Arctic Research Consortium of the United States (ARCUS) Sea Ice Prediction Network. This has become a kind of annual academic "competition" run between scientists who study the Arctic to see whose forecast most closely matches the eventual outcome.
번호 | 제목 | 글쓴이 | 조회수 | 날짜 |
---|---|---|---|---|
27339 | 연결사 [4] | 두둠칫 | 997 | |
27338 | 문법문제 _새로나온 영화 봤어?-응 even ? Such ? 실망스러웠어... [7] | ㅇㅇ | 1009 | |
27337 | 코렉트 문제중에 법 제정 관련문제 답 뭐인가요? [10] | 제바알 | 1066 | |
27336 | 독해, 답지 a에 맨 끝에 ex 들어갔던 문제 [3] | 오잉 | 881 | |
27335 | 독해 32 33번 답 아시는분? [5] | ㅇㅇ | 893 | |
27334 | 독해 타코집 문제 [2] | 힝규 | 935 | |
27333 | 청해 시간에 쉰 목소리로 기침 들이마시는 끄응 이거 하신 아저씨 [2] | 청해 | 877 | |
27332 | 독해 빈칸 [2] | ㅇ | 908 | |
27331 | 다 읽었는데도 [2] | 밍 | 986 | |
27330 | 디스카운트 gather receive 중 후자 맞죠?? [2] | 디스카운트 | 941 | |
27329 | 전에 일한적 있지? ㅇㅇ 나 두번째 삐리리야 단어 문제 [6] | ㅁㅁㅁ | 1060 | |
27328 | 문법 scheme 문제 in to by of 답뭐에용?? [3] | 문법호규 | 1023 | |
27327 | 독해 인퍼 c 있나요? [1] | ㅇㅇ | 818 | |
27326 | 양화중 민증안가져오신분 [3] | ㅇㅇ | 1062 | |
27325 | 오늘 청해 파트 5 마지막 두 문제요 [4] | 씁쓸한이물질 | 1000 | |
27324 | 독해 그 이집트? 반달리즘? 지문 뭘로 하셨나요..? [4] | 텝스 | 1119 | |
27323 | 텝관위 장사 잘하네 [4] | ㅇㅇ | 1134 | |
27322 | 500 어떻게 넘기죠ㅠㅠㅠㅠ [4] | 텝스졸업제발 | 972 | |
27321 | 청해는 어떠셨나요..? [8] | ㅁ | 1125 | |
27320 | 바로 5월 텝스 결제요 [3] | ㅇㅇ | 893 | |
27319 | 문제 뭐같이 나왔네 [4] | ㅇㅇ | 1070 | |
27318 | 뉴텝스 431점이면 구텝스 750은 된다고 봐야되나요? [4] | ㅇㅇ | 943 | |
27317 | 청해 정규교재에 나온 표현 다 와우면 몇점 정도 나오나용 [3] | 청해 | 817 | |
27316 | 텝스 셤볼 때 [5] | 다람 | 873 | |
27315 | 안녕하세요 5/8에 텝스 시험 있는데 어떤식으로 벼락치기 하면 될까요 조... [6] | 부산나얼 | 812 | |
27314 | [설문조사] 4월 24일 텝스시험 난이도 투표! | 해토지기 | 779 | |
27313 | 텝스 잘보고 싶어요 [2] | 신박한여행지 | 807 | |
27312 | 4/24 텝스정답만 맞혀야 하는데...ㅠㅠㅠㅠ 꼭 졸업해야 하는데 [5] | 123 | 1126 | |
27311 | 문법cccc [6] | 문법cccc | 896 | |
27310 | 문법 보기중에 had had [6] | had had | 915 | |
27309 | 텝스 왕초보 공부법 부탁드립니다. [3] | 텝린이 | 845 | |
27308 | 독해 18 미술관 친구 [5] | 으헝 | 1005 | |
27307 | 4.18 LC 40번 복기 [6] | 엣ㅈ | 957 | |
27306 | 텝스토익 둘 중에 뭐가 더 어렵나? [4] | 123 | 939 |
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