atmosphere
美音:[&aetm?s&f??
英音:[&aetm?s&f??
n.大气,空气,气氛
atmosphere为短语/超纲词汇
&&词频:1889
spers＝to scatter（撒,散播）
近义词, 同义词
atmosphere
/'aetm?sf??(r); `aetm?s,f?r/n 1 (a) the atmosphere [sing] the mixture of gases that surrounds the earth 大气, 大气层（包围地球的气体）.(b) [C] mixture of gases that surrounds any planet or star 包围任何星球的气体*the moon's atmosphere 月球周围的气体* an atmosphere that supports life 可以维持生命的气体. 2 [sing] air in or around a place 某一地方的空气*The atmosphere is very stuffy in here
can we open a window? 这
的空气很闷--咱们能把窗户打开吗? 3 [sing] feeling in the mind that is created by a group
mood 气氛; 情绪*An atmosphere of tension filled the room. 屋子
笼罩着紧张的气氛.* The atmosphere changed as soon as she walked in. 她一进来气氛就变了.* The atmosphere over dinner was warm and friendly. 用餐时洋溢着热情友好的气氛.
atmosphere
n [Date: ; Language: Modern L Origin: atmosphaera, from Greek
atmos 'liquid in the air, vapor' + Latin
sphaera 'sphere'] [U and C] the feeling that an event or place gives you　The hotel had a lovely relaxed atmosphere .　The atmosphere at home was rather tense.atmosphere of　An atmosphere of optimism dominated the conference.[U] if a place or event has atmosphere, it is interesting　The castle was centuries old and full of atmosphere.　The match was lacking in atmosphere. the atmospherethe mixture of gases that surrounds the Earth [C] the mixture of gases that surround a
[C usually singular] the air inside a room　a smoky atmosphere
atmosphere
农林渔/水利/环境词典:
大气 工程建筑业词典:
大气 其他:
　　大气 生产制造业词典:
1. But suppose the earth could be covered with sensors spaced one foot apart, rising at one-foot intervals all the way to the top of the atmosphere.
&&&&假设地球上可以布满传感器，每个相隔1英尺，并按1英尺的间隔从地面一直排列到大气层的顶端。
2. Waves are the children of the struggle between ocean and atmosphere, the ongoing signatures of infinity.
&&&&海浪是大海和空气相斗的产物，无限的一种不间断的标志。
3. There is too much moisture in the atmosphere today.
&&&&今天空气很潮湿。
4. This air we call the atmosphere.
&&&&我们称之为大气层。
5. The atmosphere was 30 degrees below zero centigrade and too thin to breathe.
&&&&大气温度为零下30摄氏度，空气稀薄得无法呼吸。
6. Nitrogen forms four-fifths of the atmosphere.
&&&&氮气占空气的五分之四。
7. He is forever talking about the friendly people, the clean atmosphere, the closeness to nature and the gentle pace of living.
&&&&他滔滔不绝地大谈友好的农民，洁净的空气，贴近大自然的环境和悠闲的生活节奏。
8. Yet to both classes, the need of an alternative outlook, of a change of atmosphere, of a diversion of effort, is essential.
&&&&然而对这两种人来说，都需要换一换脑子，改变一下气氛，转移一下注意力，这是不可缺少的。
9. So that we would be able to &see& the planet properly and analyse its atmosphere.
&&&&这样我们就能彻底"看见"这颗行星，并分析它的大气层。
10. Rays from the sun excite and energize the atmosphere of the earth, awakening it to flow, to movement, to rhythm, to life.
&&&&太阳光刺激了地球的大气层，并给予它能量；阳光使空气开始流动，产生节奏，获得生命。
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（atmosphere），地质学专业术语，地球就被这一层很厚的大气层包围着。大气层的成分主要有，占78.1%；氧气占20.9%；占0.93%；还有少量的、（、、、、、）和。大气层的随高度而减小，越高空气越稀薄。大气层的厚度大约在1000千米以上，但没有明显的界限。整个大气层随高度不同表现出不同的特点，分为、、、和，再上面就是了。外文名atmosphere类&&&&别地球构造分&&&&层对流层、平流层、中间层、暖层等成&&&&分氮气、氧气、氩气等
大气层对流层在大气层的最低层，紧靠表面，其厚度大约为10至20千米。对流层的大气受影响较大，、、等现象都发生在这一层内，也几乎都在这一层内存在，还存在大部分的固体杂质。这一层的气温随高度的增加而降低，大约每升高1000米，温度下降5～6℃；动、植物的生存，人类的绝大部分活动，也在这一层内，因为这一层的很明显，故称对流层。对流层以上是平流层，大约距地球表面20至50千米。平流层的空气比较稳定，大气是平稳流动的，故称为平流层。在平流层内水蒸气和尘埃很少，并且在30千米以下是，其温度在－55℃左右，温度基本不变，在30千米至50千米内温度随高度增加而略微升高。平流层以上是中间层，大约距地球表面50至85千米，这里的空气已经很稀薄，突出的特征是气温随高度增加而迅速降低，空气的垂直对流强烈。中间层以上是暖层，大约距地球表面100至800千米，最突出的特征是当照射时，太阳光中的被该层中的大量吸收，因此温度升高，故称暖层。散逸层在暖层之上，为所组成。
大气层又称大气圈，是因关系而围绕着的一层，是地球最外部的气体圈层，包围着和，大气圈没有确切的上界，在离地表公里高空仍有稀薄的和，在地下，土壤和某些岩石中也会有少量气体，它们也可认为是大气圈的一个组成部分，地球大气的主要成分为氮、氧、氩、二氧化碳和不到0.04%比例的微量气体，这些混合气体被称为，地球大气圈气体的总质量约为5.136×10^21克，相当于地球总质量的0.86%，由于作用，几乎全部的气体集中在离地面100公里的高度范围内，其中75%的大气又集中在地面至10公里高度的范围内，根据大气温度垂直分布和运动特征，在之上还可分为、中气层、等。大气层保护地表避免直接照射，尤其是；也可以减少一天当中极端温差的出现。
大气层除此之外，还有两个特殊的层，即和。层距地面20至30千米，实际介于对流层和平流层之间。这一层主要是由于氧分子受太阳光的紫外线的造成的，使氧分子变成了臭氧。很厚，大约距地球表面80千米以上。电离层是高空中的气体，被太阳光的紫外线照射，电离层由带电荷的和及部分形成的。电离层对影响很大，我们可以利用电磁短波能被电离层反射回地面的特点，来实现电磁波的远距离通讯。
在作用下，大量气体聚集在地球周围，形成数千公里的大气层。气体随离地面高度的增加而变得愈来愈稀薄。在3000公里高空仍发现有稀薄大气，有人认为，大气层的上界可能延伸到离地面6400公里左右。据科学家估算，大气质量约6000万亿吨，差不多占地球总质量的百万分之一。大气体积成分：氮78%、氧21%、氩0.93%、二氧化碳0.03%、氖0.0018%，此外还有、、及大粒度悬浮颗粒。由于的保护作用，使得大气层在及宇宙高能流的刮蚀作用下得以保存。
根据各层大气的不同特点（如温度、成分及电离程度等），从地面开始依次分为、、、、（）和。
自然状态下，大气是由混合气体、水汽和杂质组成。除去水汽和杂质的空气称为。 干洁空气的主要成分为78.09%的氮，20.94%的氧，0.93%的氩。这三种气体占总量的99.96%，其它各项气体含量计不到0.1%，这些微量气体包括、、、等稀有气体 。在大气中上述气体的含量几乎可认为是不变化的，称为恒定。
在干洁空气中，易变的成分是二氧化碳(CO2)、臭氧(O3)等，这些气体受地区、季节、 气象以及人类生活和生产活动的影响。正常情况下，二氧化碳含量在20km以上明显减少。近地层干洁空气组成如表1-1-1所示。
表1-1-1 干洁空气的气体成分
体积分数？
1.5二氧化碳
　　大气中组分是不稳定的，无论是，还是人为影响，会使大气中出现新的物质，或某种成分的含量过多地超出了自然状态下的平均值，或某种成分含量减少，都会影响生物的正常发育和生长，给人类造成危害，这是环境保护工作者应研究的主要对象。（troposphere；convection zone）。定义1：大气最下层，厚度（8～17公里）随季节和纬度而变化，随高度的增加平均温度递减率为6.5℃/公里，有和。天气现象和天气过程主要发生在这一层。应用学科：（一级学科）；（二级学科）。定义2：恒星内部冷热气体不断升降对流的区域。应用学科：（一级学科）；天体物理（二级学科）　地球对流层（troposphere）。
位于的最低层，集中了约75%的和90%以上的质量。其下界与地面相接，高度随地理纬度和季节而变化。在地区平均高度为17～18公里，在地区平均为10～12公里，极地平均为8～9公里，并且夏季高于冬季。
对流层从地球表面开始向高空伸展，直至顶，即的起点为止。它的高度因而不同，在低纬度地区大约17至18公里，在中纬度的地区高10至12公里，在高纬度地区只有8至9公里。在高纬度的地区，因为地表的会影响气流，形成了一个平均厚2公里的行星边界层。这一层的形成主要依靠而有所不同，而且亦会被逆流层的分隔而与对流层的其他部份分开。
英语里的对流层一字“Troposphere”的字首，是由的“Tropos”（意即“旋转”或“混合”）引伸而来。正因对流层是大气层中湍流最多的一层，喷射客机大多会飞越此层顶部（即对流层顶）用以避开影响飞行安全的气流。
在宇宙中恒星也有对流层， 太阳内部能量向外传播除辐射，还有对流过程。即从太阳0.71个太阳半径向外到达太阳大气层的底部，这一区间叫对流层。这一层气体性质变化很大，很不稳定，形成明显的上下对流运动。这是太阳内部结构的最外层。
接近地球表面的一层大气层，空气的移动是以上升气流和下降气流为主的对流运动，叫做“对流层”。平均厚度约为12公里，它的厚度不一， 其厚度在地球上空为8公里，在上空为17公里，是大气中最稠密的一层，总质量占大气层的四分之三还要多。大气中的水汽几乎都集中于此，是展示风云变幻的“大舞台”：、、等天气现象都是发生在对流层内。对流层最显著的特点是有强烈的对流运动。
该层有如下特点：
（1）温度随高度的增加而降低：这是因为该层不能直接吸收太阳的短波辐射，但能吸收地面反射的长波辐射而从下垫面加热大气。因而靠近地面的空气受热多，远离地面的空气受热少。每升高1公里，气温约下降6.5度。
（2）空气对流：因为岩石圈与水圈的表面被太阳晒热，而热辐射将下层空气烤热，冷热空气发生垂直对流，又由于地面有海陆之分、昼夜之别以及纬度高低之差，因而不同地区温度也有差别，这就形成了空气的。
（3）温度、湿度等各要素水平分布不均匀：大气与地表接触，水蒸气、尘埃、微生物以及人类活动产生的有毒物质进入空气层，故该层中除气流做垂直和水平运动外，化学过程十分活跃，并伴随气团变冷或变热，水汽形成、、、、、、雾等一系列天气现象。（stratosphere），又称同温层。定义1：从对流层顶到约50公里高度的大气层。层内温度通常随高度的增加而递增。底部温度随高度变化不大。应用学科：（一级学科）；（二级学科）。定义2：距地表约10～50公里处的大气层。位于对流层之上，逸散层之下。应用学科：（一级学科）；（二级学科）；流层（stratosphere），亦称同温层，是地球里上热下冷的一层，此层被分成不同的温度层，当中高温层置于顶部，而低温层置于低部。它与位于其下贴近地表的刚好相反，对流层是上冷下热的。在地区，平流层位于离地表10~50公里的高度，而在极地，此层则始于离地表8公里左右。
对流层上面，直到高于50公里这一层，气流主要表现为水平方向运动，对流现象减弱，这一大气层叫做“平流层”，又称“同温层”。这里基本上没有水汽，晴朗无云，很少发生天气变化，适于飞机航行。在20~30公里高处，氧分子在作用下，形成臭氧层，像一道屏障保护着地球上的生物免受太阳及的袭击。大气层中的人类活动示意图（Mesosphere），又称中层。自顶到85公里之间的。
该层内因含量低，同时，能被、等直接吸收的太阳已经大部分被上层所吸收，所以温度垂直递减率很大，运动强盛。附近的约为190K；空气分子吸收太阳后可发生电离，习惯上称为的D层；有时在高纬度地区夏季黄昏时有出现。
物质组成：和为主，几乎没有臭氧。该层的60-90公里高度上，有一个只有在白天出现的电离层，叫做D层。（Ionosphere）/暖（热）层（Thermosphere）。
电离层是的一个电离区域。60公里以上的整个地球大气层都处于部分电离或完全电离的状态，电离层是部分电离的大气区域，完全电离的大气区域称。也有人把整个电离的大气称为电离层，这样就把磁层看作电离层的一部分。大约距地球表面10~80公里。散逸层在暖层之上，为带电粒子所组成。
该层特点是：
除地球外，、和都有电离层。电离层从离地面约50公里开始一直伸展到约1000公里高度的地球空域，其中存在相当多的自由电子和离子，能使无线电波改变传播速极光度，发生折射、反射和散射，产生极化面的旋转并受到不同程度的吸收。
在电离作用产生自由电子的同时，电子和之间碰撞复合，以及电子附着在中性分子和原子上，会引起自由电子的消失。大气各风系的运动、极化的存在、外来带电粒子不时入侵，以及气体本身的扩散等因素，引起自由电子的迁移。在55公里高度以下的区域中，大气相对稠密，碰撞频繁，自由电子消失很快，气体保持不导电性质。在电离层顶部，稀薄，电离的迁移运动主要受的控制，称为磁层。
电离层的主要特性由、、碰撞频率、、离子温度和离子成分等的基本参数来表示。但电离层的研究对象主要是电子密度随高度的分布。电子密度（或称电子浓度）是指单位体积的自由电子数，随高度的变化与各高度上、以及太阳等因素有关。电离层内任一点上的电子密度，决定于上述自由电子的产生、消失和迁移三种效应。在不同区域，三者的相对作用和各自的具体作用方式也大有差异。
中间层以上，到离地球表面500公里，叫做“热层”。在这两层内，经常会出现许多有趣的天文现象，如、等。太阳风与地磁场（Exosphere），又名散逸层，热层顶以上是外大气层，延伸至距地球表面1000公里处。这里的温度很高，可达数千度；大气已极其稀薄，其密度为海平面处的一亿亿分之一。外大气层也叫磁力层，它是大气层的最外层，是大气层向过渡的区域，外面没有什么明显的边界。在通常情况下，上部界限在地磁极附近较低，近上空在向太阳一侧，约有9~10个高，换句话说，大约有65000千米高。在这里空气极其稀薄。
通常把1000公里之内，即电离层之内作为大气的高度，即大气层厚1000公里。的成分和各组分的分压有着极其复杂的演化过程。地球不同于金星和火星。金星的质量近于地球，由于距太阳较近，高，内部除气所产生的水蒸气不能在表面凝结成,CO2、SO2、H2S、NO、NO2等积累滞留在大气圈内形成稠密的CO2大气圈。火星距太阳较地球远，表面温度低，加之质量较小，气体易于逃逸，火星内部除气过程释出的气体，不能凝结成水体,只能形成极稀薄的CO2大气圈。地球的大气圈、水圈、和岩石圈具有协调的形成和演化过程。地球内部除气作用释出的主要气体为水蒸气、CO2、CO、HCl、CI2、HF、HBr、H2S、S、SO2、N2、H2、H、O2、CH4、NH3和稀有气体等。O2主要来源于水蒸气的光化学分解和绿色植物的。地球内部物质的熔融除气过程，大约共释放1.74×1018吨挥发性物质,其中CO2约1.22×1015吨。地球初始的大气圈属于具有成分的强还原性大气圈。通过水蒸气的凝结，原始的成为强酸性水体。随着海洋水体的增大，大气圈中CO2的积累,的地球大气圈演化为CO2-火山气体大气圈。随着水圈中碳酸盐的沉积，大气圈中CO2分压降低，演化为的弱氧化的CO2大气圈。生物的繁殖，碳酸盐沉积量的增长和植物的出现,CO2大气圈逐步演化为现今的N2-O2大气圈。
温度分布变化
随着高度的增加而降低
随着高度的增加而升高
随着高度的增加而降低
80~500千米
随着高度的增加而升高
500~1000千米
随着高度的增加而升高
在宇宙行星中都有大气层，大型行星比地球的大气层厚，成分有的多，有的少。
人类的活动使地球大气圈中CO2含量明显增加，每年通过煤和石油的燃烧产生的CO2总量为6.2×10^9吨，相当于现今大气圈中CO2含量的1/250。温室效应的增长，臭氧层的破坏，一系列环境生态的恶化，对人类的生存环境提出了严重的挑战。“全球变化──地圈和生物圈十年”计划已成为当代科学研究的焦点，全世界的科学家将为人类生存环境的演化和预测提出科学对策。
新手上路我有疑问投诉建议参考资料 查看From Wikipedia, the free encyclopedia
This article is about atmospheres in general.
For Earth's atmosphere, see .
For other uses, see .
"Atmospheric environment" redirects here. For the scientific journal, see .
Mars' thin atmosphere
The layers of Earth's atmosphere
An atmosphere (New Latin atmosphaera, created in the 17th century from
?τμ?? [atmos] "vapor" and σφα?ρα [sphaira] "sphere") is a layer of
surrounding a
of sufficient
that is held in place by the
of the body. An atmosphere is more likely to be retained if the gravity is high and the atmosphere's temperature is low.
The , which is mostly , also contains
used by most
for , also protects living organisms from genetic damage by
. Its current composition is the product of billions of years of biochemical modification of the
by living organisms.
describes the outer region of a star, and typically includes the portion starting from the
outwards. Stars with sufficiently low temperatures may form compound
in their outer atmosphere.
Main article:
Atmospheric pressure is the
per unit area that is always applied perpendicularly to a surface by the surrounding gas. It is determined by a planet's gravitational force in combination with the total mass of a column of gas above a location. On Earth, units of air pressure are based on the internationally recognized
(atm), which is defined as 101,325
(760  or 14.696 ).
The pressure of an atmospheric gas decreases with altitude due to the diminishing mass of gas above each location. The height at which the pressure from an atmosphere declines by a factor of
with a value of 2.71828..) is called the
and is denoted by H. For an atmosphere with a uniform temperature, the scale height is proportional to the temperature and inversely proportional to the mean
of dry air times the planet's gravitational force per unit area of on the surface of Earth. For such a model atmosphere, the pressure declines exponentially with increasing altitude. However, atmospheres are not uniform in temperature, so the exact determination of the atmospheric pressure at any particular altitude is more complex.
Main article:
, the force that holds down an atmosphere, differs significantly among the planets. For example, the large gravitational force of the giant planet
is able to retain light gases such as
that escape from objects with lower gravity. Secondly, the distance from the Sun determines the energy available to heat atmospheric gas to the point where its molecules'
exceed the planet's , the speed at which gas molecules overcome a planet's gravitational grasp. Thus, the distant and cold , , and
are able to retain their atmospheres despite relatively low gravities. , theoretically, may also retain thick atmospheres.
Since a gas at any particular temperature will have molecules moving at a wide range of velocities, there will almost always be some slow leakage of gas into space. Lighter molecules move faster than heavier ones with the same thermal , and so gases of low
are lost more rapidly than those of high molecular weight. It is thought that
may have both lost much of their water when, after being
into hydrogen and oxygen by solar , the hydrogen escaped. 's
helps to prevent this, as, normally, the solar wind would greatly enhance the escape of hydrogen. However, over the past 3 billion years the Earth may have lost gases through the magnetic polar regions due to auroral activity, including a net 2% of its atmospheric oxygen.
Other mechanisms that can cause
are -induced sputtering,
erosion, , and sequestration — sometimes referred to as "freezing out" — into the
Atmospheres have dramatic effects on the surfaces of rocky bodies. Objects that have no atmosphere, or that have only an exosphere, have terrain that is covered in . Without an atmosphere, the planet has no protection from , and all of them collide with the surface and create craters.
A rocky body with a thick atmosphere does not have significant craters on its surface. The friction generated when a meteor enters an atmosphere causes the vast majority to burn up before hitting the surface. When craters do impact, the effects are often erased by the action of wind. As a result, craters are rare on objects with atmospheres.
All objects with atmospheres have
is a significant factor in shaping the terrain of rocky planets with atmospheres, and over time can erase the effects of both craters and . In addition, since s can not exist without pressure, an atmosphere allows liquid to be present at the surface, resulting in ,
are known to have liquids at their surface and terrain on the planet suggests that
had liquid on its surface in the past.
Earth's atmospheric
scatter blue light more than other wavelengths, giving the
a blue halo when seen from .
Initial atmospheric makeup is generally related to the chemistry and temperature of the local
during planetary formation and the subsequent escape of interior gases. The original atmospheres started with the radially local rotating gases that collapsed to the spaced rings that formed the planets. They were then modified over time by various complex factors, resulting in quite different outcomes.
The atmospheres of the planets
are primarily composed of , with small quantities of , ,
and traces of other gases.
The atmospheric composition on Earth is largely governed by the by-products of the very life that it sustains. Dry air from
contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, and traces of hydrogen, helium, and other "noble" gases (by volume), but generally a variable amount of water vapour is also present, on average about 1% at sea level.
The low temperatures and higher gravity of the —, ,
and —allows them more readily to retain gases with low . These planets have hydrogen–helium atmospheres, with trace amounts of more complex compounds.
Two satellites of the outer planets possess non-negligible atmospheres: , a moon of Saturn, and , a moon of Neptune, which are mainly . , in the nearer part of its orbit, has an atmosphere of nitrogen and methane similar to Triton's, but these gases are frozen when farther from the Sun.
Other bodies within the
have extremely thin atmospheres not in equilibrium. These include the
(sodium gas),
The atmospheric composition of an
was first determined using the . Planet
is a gas giant with a close orbit around a star in the
. Its atmosphere is heated to temperatures over 1,000 K, and is steadily escaping into space. Hydrogen, oxygen, carbon and sulfur have been detected in the planet's inflated atmosphere.
Main article:
consists, from the ground up, of the
(which includes the
or peplosphere as lowest layer),
(which includes the ), ,
(which contains the ),
and also the . Each of the layers has a different , defining the rate of change in temperature with height.
Three quarters of the atmospheric mass resides within the troposphere, and the depth of this layer varies between 17 km at the equator and 7 km at the poles. The , which absorbs
energy from the Sun, is located primarily in the stratosphere, at altitudes of 15 to 35 km. The , located within the thermosphere at an altitude of 100 km, is commonly used to define the boundary between the Earth's atmosphere and . However, the
can extend from 500 up to 1,000 km above the surface, where it interacts with the planet's .
Other astronomical bodies such as these listed have known atmospheres.
Atmosphere of
Main article:
The circulation of the atmosphere occurs due to thermal differences when
becomes a more efficient transporter of heat than . On planets where the primary heat source is solar radiation, excess heat in the tropics is transported to higher latitudes. When a planet generates a significant amount of heat internally, such as is the case for , convection in the atmosphere can transport thermal energy from the higher temperature interior up to the surface.
From the perspective of the planetary , the atmosphere is an evolutionary agent essential to the
of a . The
transports
and other particles which erodes the
and leaves
( processes).
and , which depend on the composition, also influence the relief. Climate changes can influence a planet's geological history. Conversely, studying surface of Earth leads to an understanding of the atmosphere and climate of a planet — both its present state and its past.
For a , the composition of the atmosphere determines the
and its variations.
For a , the composition is closely dependent on the appearance of the life and its .
(evaporimeter)
, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
Seki, K.; Elphic, R. C.; Hirahara, M.; Terasawa, T.; Mukai, T. (2001). . Science 291 (5510): . :. :.  .
Weaver, D.; Villard, R. (). . Hubble News Center.
Sanchez-Lavega,, Agustin (2010). An Introduction to Planetary Atmospheres. Taylor & Francis.  .
- an Open Access journal