飛機(jī)西向東比東向西反而快的原因

1、為什么飛機(jī)從東向西飛比從西向東飛的時(shí)間要多因?yàn)榈厍蛟谵D(zhuǎn)（不對(duì)）我有想過這一點(diǎn)，但是飛機(jī)的速度是以地球?yàn)閰⒄障档陌。词拱茨愕睦斫?，那也?yīng)該是 由東向西更快才對(duì)嘛。不是地球自轉(zhuǎn)引起的，而是喜瑪拉亞山形成的大氣流，他的方向是從西向東流動(dòng)，造成飛 機(jī)向東走要快于向西走。我們可以設(shè)想飛機(jī)如果在天上不動(dòng)，由于地球的自轉(zhuǎn)，飛機(jī)是背 離目的地的。飛機(jī)由東向西飛和由西向東飛所用的時(shí)間為什么不同？比如上海飛成都要3小時(shí)20分， 而成都飛上海只要2小時(shí)20分。地球是自西向東自轉(zhuǎn)的，那么從東往西飛的飛機(jī)應(yīng)該是和地球的自轉(zhuǎn)方向逆向飛行， 所用時(shí)間應(yīng)該比從西向東的順向飛行所用時(shí)間短才對(duì)??！有朋友能從理論的角度幫忙 解釋

2、一下嗎？為什么飛機(jī)從東往西飛比從西往東飛花的時(shí)間長(zhǎng)？想了半天沒有明白，由于地球自轉(zhuǎn)，不 是應(yīng)該反過來么？實(shí)際上，飛行速度的差異并非是直接由于地球自轉(zhuǎn)引起的，而是地球的自轉(zhuǎn)引起地球上方 大氣向一個(gè)方向運(yùn)動(dòng)，而大氣的運(yùn)動(dòng)使得飛機(jī)相對(duì)地面的速度產(chǎn)生差異。由于地球表面受到光照射的角度不同，在赤道所在的熱帶地區(qū)，大氣被加熱上升，形成熱帶低氣 壓帶、而極地由于冷，空氣下沉而形成極地高氣壓帶，同時(shí)，在副熱帶地區(qū)由于空氣下沉形成副 熱帶高壓帶，而在副極地地區(qū)由于北上或南下空氣遇到冷空氣抬升而形成副極地低壓帶。那么， 由于氣壓的不同，從而使氣壓帶之間有空氣流動(dòng)，比如空氣就從副熱帶高壓流帶向副極地低壓帶。 然而由

3、于地轉(zhuǎn)偏向力的作用，空氣并不能沿著經(jīng)線方向流動(dòng)，而是會(huì)偏轉(zhuǎn)一個(gè)角度，由此，就會(huì) 在副熱帶高壓帶和副極地低壓帶之間，形成一片西風(fēng)帶（稱為盛行西風(fēng)或中緯西風(fēng)帶）。Subtropical jet stream傾I ?無克Pl Jokr.ccjrn龍L * *槌地高氣壓帶 化二-虹粗地東風(fēng)明極地低壓帶盛行西風(fēng)JH的帶高壓帶/ / /東北信風(fēng)己.騷iHttH壓帶_尸、未南at風(fēng)-帶高氣壓帶U.*、* X盛行西風(fēng)制極地低r壓帶極地東風(fēng)r =極地高氣嘛西風(fēng)帶的位置涵蓋了我國(guó)以及歐亞大陸的大部分區(qū)域。在西風(fēng)帶地區(qū)的平流層下部，由于對(duì)流層氣流與其相互作用以及高海拔的太陽(yáng)加熱作用，使得對(duì) 應(yīng)地區(qū)的平流層下部產(chǎn)生一

4、條數(shù)百公里寬的西風(fēng)帶，這一風(fēng)帶被稱為高速氣流帶Jet Stream）， 在平流層底、平流層頂飛行的飛機(jī)正是受到這一風(fēng)帶的影響而產(chǎn)生速度的差異。同時(shí)，飛機(jī)在飛行過程中，具有一個(gè)經(jīng)濟(jì)速度（就是相對(duì)來說單位飛行距離中油耗較低），這一 速度是相對(duì)空氣的速度，而不是相對(duì)于地面的速度，這一速度也被稱作空速。因此，當(dāng)飛機(jī)以經(jīng) 濟(jì)速度進(jìn)行飛行時(shí)，實(shí)際上相對(duì)地面的速度（地速），是飛機(jī)的空速和大氣相對(duì)地面速度的和速 度。因此可見，對(duì)于飛行在歐亞大陸上空的航線來說，大多要受到高速氣流帶的影響，因此在空速一 定時(shí)，從東向西飛行的地速要慢于從西向東飛行的地速，因此，使得飛機(jī)從東往西飛比從西往東 飛花的時(shí)間長(zhǎng)。當(dāng)然，如果

5、在其他風(fēng)帶飛行，情況就會(huì)不一樣了。為什么飛機(jī)向東飛比向西飛快呢？比如：北京飛迪拜要10小時(shí)，迪拜飛北京只要7小時(shí)。與同事閑聊的時(shí)候，說道這個(gè)話題。幾年前就產(chǎn)生這樣的疑問，看了相關(guān)的解釋，知 道這不是直覺上地球自轉(zhuǎn)的結(jié)果，而是平流層的西風(fēng)帶的影響。同事不信，讓我找出 相關(guān)解釋，這里引用一下英文版的，順便學(xué)下英文吧。Why do airplanes take longer to fly West than East? HYPERLINK /question.php?number=607 /question.php?number=607Can you please tell me what fact

6、ors cause airplane times to differ between travels to east and to west.Its interesting that you ask this - I am directly experiencing it right now as I sit on an airplane from the UK. It took 5 hours to go West-East on this journey, but is taking about 7 East-West. The reason for the difference is a

7、 atmospheric phenomena known as the jet stream. The jet stream is a very high altitude wind which always blows from the West to the East across the Atlantic. The planes moving at a constant air speed thus go faster in the West-East direction when they are moving with the wind than in the opposite di

8、rection.Every planet has global wind which are mostly determined by the way the planet rotates and how evenly the Sun illuminates it. On the Earth the equator gets much more Sun than the poles. resulting in warmer air at the equator than the poles and creating circulation cells (or Hadley Cells) whi

9、ch consist of warm air rising over the equator and then moving North and South from it and back round.The Earth is also rotating. When any solid body rotates, bits of it that are nearer its axis move slower than those which are further away. As you move north (or south) from the equator, you are mov

10、ing closer to the axis of the Earth and so the air which started at the equator and moved north (or south) will be moving faster than the ground it is over (it has the rotation speed of the ground at the equator, not the ground which is is now over). This results in winds which always move from the

11、west to the east in the mid latitudes.All of the global wind patterns are illustrated in the below diagram taken from the AmherstAstronomy Association Website.You say that wind not the Earths rotation, causes the differences in flight times to the east or west But what causes the headwind and tailwi

12、nd? Maybe high up, away from the Earth, the rotation of the atmosphere is lagging behind relative to the rotation of the Earth. You call it a wind, because it is movement of the air relative to the Earths rotation. So maybe, the difference in travel time is still explained by the rotation of the Ear

13、th?( HYPERLINK /question/atmosphere/q0117.shtml /question/atmosphere/q0117.shtml)You must be referring to several past questions weve answered on differences in flight times between Los Angeles and Bombay, London and New York, and California and Hawaii. In all of those discussions, we explained why

14、flying to the west takes longer than flying to the east and how it is the effect of the wind, and not the rotation of the Earth, that causes these differences.Now your theory might have some merit if not for one simple fact. If what you say is true, then the wind should blow in the opposite directio

15、n of the Earths rotation since the wind is lagging behind. But in reality, the Earth rotates to the east and the winds over most of theplanet blow to the east as well. These winds are called the Prevailing Westerlies since they blow out of the west and to the east. Furthermore, the Earth rotates fas

16、test at the Equator, so according to your theory, this region is where the winds should blow the hardest. But as you can see below, the region along the Equator is referred to as the Doldrums because there is essentially no prevailing wind in this area.Prevailing windsSo what does cause the wind to

17、blow in a given direction? While the Earths rotation does play a role, it is a somewhat indirect one. The primary factor that affects the formation of winds is differences in atmospheric pressure. As is true throughout nature, any fluid will try to move from a region of high pressure to a region of

18、low pressure. The principal causes of these differences in pressure are related to the absorption of heat due to solar radiation.Heating of the atmosphere will obviously vary with time of day and location on the Earth. For example, the mid-latitudes towards the Equator receive much more solar radiat

19、ion than do high latitudes near the poles. As air is heated, it rises creating regions of lower pressure.Air from regions of higher pressure is then pulled into these low pressure zones creating wind. We feel this effect most forcefully during the winter months of the Northern Hemisphere. The warmer

20、 air of the mid-latitudes rises creating a low pressure, but the colder, denser air of the Arctic regions is at higher pressure. The pressure difference between these regions of warmer and cooler air pulls the jetstream further and further to the south bringing that bitterly cold Arctic wind over th

21、e central and eastern United States. This behavior occurs most often from December through February, often creating the sub-zero cold spells and major snowstorms that this time of year is known for. As Spring approaches and the North Pole tilts more towards the Sun, the differences in pressure due t

22、o the absorption of solar radiation become less pronounced and the jetstream stays further north over Canada.An additional effect of solar radiation is its influence on large bodies of water, such as oceans or large lakes. These bodies of water also absorb solar radiation but release it at a much sl

23、ower rate than does the atmosphere, or the land. On a local level, this behavior has the effect of creating breezes that tend to moderate the temperature extremes near shore. Land heats up and cools down more rapidly than does water. During daytime, the atmosphere over land becomes warmer thereby ex

24、panding and becoming less dense, and rises. This behavior creates a low pressure region over land that pulls in air from over water, where the pressure is higher. In the evening, temperatures over land drop more quickly than over water causing the breeze to operate in the reverse direction. Similar

25、effects also operate on a global scale so that the distribution of water around the globe has a significant impact on the generation of wind. It is therefore not surprising that the direction of the prevailing winds illustrated above matches closely with the direction of the ocean currents shown below.Ocean currents, blue represents cold water, red warm waterNevertheless, you are correct in that the Earths rotation does play some role in the formation of winds, and therefore has an indirect effect on the difference in east-to-west flight times. The rotation of the Earth crea