Nope. 1041MPH winds out of the east at the equator, fading away to nothing at the poles.
For a given latitude … motion will be 1040 mph times the cosine of that latitude … when observed from a frame of reference that is stationary to the background stars.
You mean “if the atmosphere didn’t rotate with the Earth”.
You mean “a frame of reference that is non-rotating compared to the background stars”.
If the atmosphere didn’t move at all, as observed from an inertial frame of reference that is stationary compared to the average motion of the 6,000 stars in our neighborhood which are visible to the naked eye, Earth would be revolving around our sun in a vacuum, forming a spiral getting farther and farther away from the tiny cloud of gas which used to be our atmosphere.
Ummm … no … I mean stationary to the background stars. This is fine for a reasonably short period of time. I understand the Earth is moving in it’s orbit around the sun, but this motion is along the ecliptic, the equivalent to the equator. The Coriolis effect doesn’t appear in these situations.
I’m referring to the motion of the planet at a point near the surface, whether it be land, sea or sky. The instantaneous linear velocity is 1,040 mph on the equator, 720 mph at 60º latitude and 0 mph at the poles … towards the East.
You’re describing the motion of a point on the surface of the planet, relative to the center of the planet, i.e. a frame of reference which follows the planet in its orbit around the sun but doesn’t rotate relative to the visible stars. Let’s call this frame A. This is not an Inertial Frame of Reference. But, if we only look at “a reasonably short period of time” (your words) we could certainly find an IFR called B which is tangential to the frame you described and the difference between A and B could be made negligible if we can make the time arbitrarily small. But you admit that A changes as Earth revolves around the sun (moving this way in the winter time, that way in the summer time, et cetera), so our choice for B would depend on what time of year you chose and where Earth would be in its orbit. So really, there’s B1, B2, B3, B4, an infinite number of B’s (all of them IFRs) which are tangent to A at various times.
Now consider the center of mass of the 6,000 stars in our neighborhood which are visible to the naked eye. Take the frame of reference in which that center of mass has zero velocity and the net angular momentum is zero. Let’s call this fame C. It is also non-inertial because it’s revolving around the center of the galaxy as our sun and it’s companions move. But, at any given moment in time, we could find an IFR D which is tangential to C. In fact, there are infinitely many Ds (D1, D2, etc.) depending on which moment in time you select.
So, A, B, C, and D are four different frames of reference. If our atmosphere was truly stationary and didn’t move at all (relative either to B, or C, or D) then Earth would be stripped naked, soaring off in to the vacuum following frame A. The only way in which this doesn’t happen is the fact that when Earth follows A, the atmosphere also follows A.
Even if we ignore the problems of which point in time is being selected, just take a snapshot of the galaxy right this instant and calculate frame B and frame D, do you have any evidence that the difference between B and D is exactly zero? Given the huge speeds involved, I’d say the odds against that being the case are astronomical (no pun intended).
The jetstreams have been mentioned in several postings. They owe their existence to Coriolis forces. Without Coriolis effect, tropospheric circulation would rise at the tropics, split into nortward and southward flows, and descend at the poles. Coriolis forces turn the flow, and create two or three separate circulation zones in each hemisphere. (usually two, sometimes three depending on “stuff”). The jetstreams circulate at the boundary of these circulation cells.
So as much as the jetstreams impact aeronavigation, this is a result of coriolis forces.
Not clear where you’re going with this … the frame of reference doesn’t rotate, we observe the planet rotating beneath us … land, sea, sky and any airplanes that happen to be flying in the air. This “reasonably short period of time” when describing instantaneous linear velocity is in fact the infinitely short period of time. This is the only point I’m trying to make, the speed of the air decreases as we move up in latitude from an IRF, pick any one you want where the Earth is rotating underneath once a day.
If we were to fly from Anchorage, Alaska to Helsinki, Finland; we’d fly right over the North Pole. Helsinki isn’t rotating independently of the air or the plane that’s in the air, all this rotates together.
So “simply stated, Coriolis acting directly on the airplane is utterly swamped by wind acting on the airplane over the same time interval.”
ETA: **watchwolf49 **wasn’t there when I started; this isn’t a response to him. But I see the disconnect between he & sbunny8 is the two frames I discuss below. One is centered on the earth center and is NOT rotating. The other is centered there and IS rotating. Big difference in how everything plays out depending on which frame you’re talking about.
Talking about various reference frames, Coriolis, etc. …
A fun scenario is a 12 hour flight that crosses over the North pole at the 6 hour mark. There aren’t any real routes that do that, but if you imagine non-stop Boise Idaho to Tashkent Kazakhstan or Gander Newfoundland to Harbin Manchuria you get the idea.
If you take off at midnight local time heading due north you’re progressing from the dark side of the Earth towards a destination that’s having noon at your take off time. IOW, you’re flying from the outside side of the Earth’s orbit towards the sun and if the Earth wasn’t rotating you’d end up on the inside side of the Earth’s orbit.
But the Earth *is *rotating. So by the time you get to the pole you’ll have pivoted 90 degrees to the left in Earth-center-centered coordinates despite having flown due North the entire time and not turning at all in Earth-surface-centered coordinates.
As you pass the pole you switch from going North to going South without turning left or right even a smidgen. As you drone due South towards Tashkent you’ll rotate another 90 degrees to the left. And when you land you’re in the very same place you left from; at least in Earth-center-centered coordinates. You’re back on the outside of the orbit. At local midnight.
If we ignore the 23 degree tilt of the Earth’s axis and pretend that’s zero, then as you head North you’d see what looks like a twilight leading to sunrise. When you left Boise you expected it to appear in front of you since you’re heading right towards the Sun. By the time you approach the pole the Sun will be of the right and ahead of you but still below the horizon. Just as you pass the Pole it’ll just skim the horizon directly off to your right. Then set into evening twilight ever more off your right rear.
And from one end of the flight to the other you never turn right or left even a smidgen.