海洋中有多少水?
文章來源:未知 文章作者:meng 發布時間:2009-11-13 03:22 字體: [ ]  進入論壇
(單詞翻譯:雙擊或拖選)

The calculation of variations(變更) in the sea level is relatively1 simple. It is by far more complicated to then determine the change in the water mass. A team of geodesists(測地學) and oceanographers(海洋學家) from the University of Bonn, as well as from the GFZ German Research Centre for Geosciences and the Alfred-Wegener Institute for Polar and Marine2 Sciences, two centres of the Helmholtz Association, have now, for the first time succeeded in doing this. The researchers were able to observe short-term fluctuations3(起伏現象) in the spatial4 distribution(空間分布) of the ocean water masses. Their results are, amongst others, important for improved climate models. In order to determine the ocean volume in a certain region, one only needs to know, in addition to the topography(地形,地勢) of the seabed, the height of the sea level. For this purpose, researchers have long been resorting to gauging5 stations(水位站) and satellite altimetric(高度計) procedures. The ocean mass depends, however, not only on the volume, but also on the temperature and on the salt content. Water expands when heated. Warm water, thus, weighs less than the same quantity of cold water.

For the calculation of the ocean mass it is, therefore, necessary to know the temperature and salt content profiles. However, this is not easy to quantify(定量,量化). "For our study we, therefore, combined different procedures so as to be able to judge changes in mass", explains Professor Dr. Juergen Kusche. The geodesist from Bonn is co-author of a scientific paper, which has just been published in the Journal of Geophysical Research.

On the one hand the researchers used data from the German-American satellite mission GRACE where the distance between two satellites (popularly known as Tom and Jerry as one chases the other in the same orbit ) are measured exactly to thousandths of millimetres. The larger the ocean mass at a certain point of the Earth, the stronger the gravitational strength. This influences the flight altitude of the satellites and thus the distance from each other. The gravitation(引力) and, hence(今后,從此), the mass distribution can be calculated from the change in distance between the two satellites.



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1 relatively bkqzS3     
adv.比較...地,相對地
參考例句:
  • The rabbit is a relatively recent introduction in Australia.兔子是相對較新引入澳大利亞的物種。
  • The operation was relatively painless.手術相對來說不痛。
2 marine 77Izo     
adj.海的;海生的;航海的;海事的;n.水兵
參考例句:
  • Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
  • When the war broke out,he volunteered for the Marine Corps.戰爭爆發時,他自愿參加了海軍陸戰隊。
3 fluctuations 5ffd9bfff797526ec241b97cfb872d61     
波動,漲落,起伏( fluctuation的名詞復數 )
參考例句:
  • He showed the price fluctuations in a statistical table. 他用統計表顯示價格的波動。
  • There were so many unpredictable fluctuations on the Stock Exchange. 股票市場瞬息萬變。
4 spatial gvcww     
adj.空間的,占據空間的
參考例句:
  • This part of brain judges the spatial relationship between objects.大腦的這部分判斷物體間的空間關系。
  • They said that time is the feeling of spatial displacement.他們說時間是空間位移的感覺。
5 gauging 43b7cd74ff2d7de0267e44c307ca3757     
n.測量[試],測定,計量v.(用儀器)測量( gauge的現在分詞 );估計;計量;劃分
參考例句:
  • The method is especially attractive for gauging natural streams. 該方法對于測量天然的流注具有特殊的吸引力。 來自辭典例句
  • Incommunicative as he was, some time elapsed before I had an opportunity of gauging his mind. 由于他不愛說話,我過了一些時候才有機會探測他的心靈。 來自辭典例句
TAG標簽: water ocean sea
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