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研究地球冰冻层的炫酷方法

NASA ScienceCasts: Cool Ways of Studying the Cryosphere

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研究冰冻层的炫酷方式
Cool Ways of Studying the Cryosphere
——NASA出品
– presented by Science@NASA.
地球气候系统的一个关键因素就是冰冻层
One of the key elements of Earth’s climate system is the cryosphere
地球上各种形态的冰雪在此呈现
– the many forms of ice found on Earth.
NASA的两个新任务是
Two new NASA missions use different
使用不同的技术来帮助科学家
technologies to help scientists better understand
更好地了解这些冰层对地球的影响
how frozen water is affecting our planet.
这两种技术都会使用到卫星数据记录
Both will continue satellite data records
该记录很大程度上提高了我们对地球冰冻区的理解
that have greatly improved our understanding of Earth’s frozen regions.
这两种技术分别是GRACE Follow-On和ICESat-2
Meet GRACE Follow-On (GRACE-FO), and ICESat-2.
GRACE-FO任务启动于2018年5月22日
The GRACE-FO mission, which launched on May 22, 2018
加载了一只太空x猎鹰九号火箭
aboard a SpaceX Falcon 9 rocket,
该技术的合作伙伴是德国地球科学研究中心
is a partnership with the German Research Centre for Geosciences.
和2002-2017年的GRACE任务
Like the preceding GRACE mission,
相类似的是
which operated from 2002-2017,
这对GRACE FO卫星测量的是
the pair of GRACE-FO satellites measure minute variations
地球引力场的分钟变化
in Earth’s gravitational field
来决定随时间流逝 质量是如何在我们的星球上运动的
to determine how mass is moving around our planet over time.
弗兰克•韦伯博士 NASA JPL的GRACE-FO项目科学家解释到
Dr. Frank Webb, GRACE-FO project scientist at NASA’s Jet Propulsion Laboratory (JPL) explains,
“GRACE-FO的测量展示了
“GRACE-FO’s measurements show the migration
质量从地球的一处移动到另一处的轨迹
of mass from one place on Earth to another,
地球上哪些区域质量在增加 哪些在减少
which regions of Earth are gaining mass and which are losing.
这些细微变化是能通过
It is sensitive enough to see small changes
冰和水的分布观察到的
in the distribution of ice and water,
这让我们了解到
which allows us to understand the
水循环的趋势和驱动因素
trends and drivers of the water cycle,
包括了冰盖对海平面上升的影响
including the contributions of the ice sheets to sea level rise.”
冰川消融 质量减小
As ice sheets melt, they lose mass,
会悄然改变地心引力
which slightly alters Earth’s gravity,
改变控制卫星轨道的力量
changing the forces controlling the orbits of the satellites.
GRACE-FO彼此轨道为135英里(220千米)
The two GRACE-FO satellites orbit ~135 miles (220 km) from one another,
相互牵引
with one satellite leading the other.
如果牵引卫星遇到重力变化
If the lead satellite encounters a change in gravity,
它的速度也会变化 并影响尾随卫星
its speed changes as does its relative distance to the trailing satellite.
微波和激光常用来
Microwaves and lasers are used to measure the tiny changes
在猫和老鼠的游戏中测量
in distance between the two satellites
两颗卫星之间的微小距离变化
in a constant game of cat and mouse.
通过对同一地点的多道次挤压
By taking measurements of multiple passes over the same location,
科学家能绘出此处重力场的大致图像
scientists can create maps of that location’s gravitational field.
在地球上寒冷的地方
Over Earth’s frozen regions,
这些信息表明了冰雪覆盖 冰川覆盖和削减的区域
this information shows where ice sheets and glaciers are gaining or losing mass.
GRACE-FO 全面地展现了
While GRACE-FO gives a global view of changes
地球质量分布的变化
in the distribution of mass on Earth,
ICESat-2会提供关于冰层高度的补充措施
ICESat-2 will provide complementary measurements of ice sheet height.
ICESat-2计划在2018年秋发射
ICESat-2, which is scheduled to launch in the fall of 2018,
是一颗在NASA戈达德太空飞行中心外运行的卫星
is a single satellite operated out of NASA’s Goddard Space Flight Center
会向地球发射激光信号
that uses its laser to shoot beams of light to Earth.
通过计算这些激光的传播时间
Scientists can determine a location’s elevation
科学家可以确定相应位置的高程
by measuring the travel time of these laser pulses.
在2003年到2010年实施的原ICEsat任务
The original ICESat mission, which operated from 2003-2010,
利用的是单束极光测量
used a single laser beam.
而ICESat-2 使用6束极光来提高测量精确度和分辨率
ICESat-2 uses 6 beams to improve accuracy and resolution.
使用6束激光 在激光的轨迹中
Using 6 beams gives scientists multiple points of data
科学家能获得多角度的数据
within the laser’s footprint,
科学家能够测量相应区域的斜率
allowing them to measure the slope
并在高程时时有变动的区域
of an area and then separate static slope data
分离静态的斜率数据
from the area’s changes in elevation over time.
那么为什么高程信息如此重要呢
Why is this elevation information important?
Thorsten Markus博士
Dr. Thorsten Markus,
是冰冻层研究的首席 他表示
chief of the Cryospheric Sciences Lab at Goddard explains,
ICEsat-2的轨道每90天会发送回测量数据
“ICESat-2’s orbit repeats measurements every 90 days,
让我们能够观察到相应变化
which allows us to see change
同时帮助我们确定变化的诱因
while also helping to determine the drivers of that change.
比如 一个地区的雪融能平衡另一地区的降雪吗
For example, is melting in one region balanced by snowfall in another?”
Grace-FO和ICEsat-2
Grace-FO and ICESat-2 will be the
将是NASA最新的研究冰冻层
newest NASA missions being used to study the cryosphere
及其在地球系统中作用的任务
and its role in the Earth system.
不仅是为完成研究冰冻层的目的
In addition to their cryospheric objectives,
这些卫星也为地球系统其他组成的运作
these satellites provide important insight into the behavior
提供了重要的信息
of other Earth system components,
比如GRACE-FO也与地下水的储存变化有关
like changes in underground stored water for GRACE-FO
ICEsat-2也与生态系统结构有关
and ecosystem structure for ICESat-2.
这些设备研究地球系统众多组成的能力
The ability of these sensors to address multiple Earth system components
有力地证明了NASA将地球看作一个
is a good example of how NASA treats the Earth
复杂且相互作用的系统
as a complex, interacting system.
欲了解更多关于冰冻层和其它炫酷的科学知识
To learn more about the cryosphere and other cool science topics,
请访问 science nasa gov
visit science.nasa.gov.

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NASA研究冰雪圈的方法

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