B1 中級 英國腔 108 分類 收藏
開始影片後,點擊或框選字幕可以立即查詢單字
字庫載入中…
回報字幕錯誤
NASA scientists have performed the first multi-year study
using satellite data to measure the 3-D distribution of dust
that travels from the Sahara Desert to the Amazon rainforest.
The Sahara is the world's largest desert.
At more than 3 million square miles,
it's almost the size of the continental United States.
Each year, Saharan dust is lifted from the ground,
and transported by winds on a 3000-mile journey
across the Atlantic Ocean.
A portion of the dust collects in the Amazon basin
—the largest rainforest on the planet.
Although dust particles are small,
no larger than around a tenth of the width of a human hair,
they form massive plumes that can be seen from space.
NASA's CALIPSO satellite was launched in 2006
to study the vertical structure of clouds and particles
in Earth's atmosphere.
CALIPSO observations from 2007 through 2013
show that on average,
182 million tons of dust leaves Africa each year.
Of this amount, about 27 million tons
is deposited in the Amazon basin.
Sahara dust contains phosphorus,
which is an important nutrient for plants.
In the tropic region, the phosphorus is quite limited.
So it's important to estimate how much dust
from the desert is transported to the Amazon.
The study shows Saharan dust adds phosphorous to the soils
that help compensate for losses
due to surface runoff and floods.
However, the amount of dust transported to the Amazon
changes from year to year.
According to the study, this variation is closely associated
with changes in rainfall in the Sahel,
a belt of semi-arid land just south of the Sahara.
When the Sahel was dry, the dust transport to the Amazon
in the next year would increase.
When it was wet,
dust transport would decrease.
Using satellites to get a clear picture of dust is important
for understanding, and eventually using computers to model
where that dust will go,
now and in future climate scenarios.
提示:點選文章或是影片下面的字幕單字,可以直接快速翻譯喔!

載入中…

以3D顯像衛星數據 從撒哈拉沙漠到亞馬遜沙塵之旅 (NASA | Satellite Tracks Saharan Dust to Amazon in 3-D)

108 分類 收藏
serena 發佈於 2018 年 11 月 20 日
看更多推薦影片
  1. 1. 單字查詢

    在字幕上選取單字即可即時查詢單字喔!

  2. 2. 單句重複播放

    可重複聽取一句單句,加強聽力!

  3. 3. 使用快速鍵

    使用影片快速鍵,讓學習更有效率!

  4. 4. 關閉語言字幕

    進階版練習可關閉字幕純聽英文哦!

  5. 5. 內嵌播放器

    可以將英文字幕學習播放器內嵌到部落格等地方喔

  6. 6. 展開播放器

    可隱藏右方全文及字典欄位,觀看影片更舒適!

  1. 英文聽力測驗

    挑戰字幕英文聽力測驗!

  1. 點擊展開筆記本讓你看的更舒服

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔