Corialis effect, northern hemisphere, but north to south wind?

LongRoadBob

LongRoadBob

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Jacker
I actually just now heard all of you with your collective groans. Cut it out!
This is the "pilot training" sub forum, so...you know, just move on, right?

I have it from a few sources here in Norway that have experience pilot training in the USA, that though our curriculum is a good deal harder in theory, the USA is a good deal better trained in stick and rudder flying. Personally I'd feel better if ours was more like yours, but I am stuck with having to pass the exam here and they possibly expect more theory. I don't know, exam questions from the US folk have posted here seem pretty hard to me, but whenever I ask a question here about some of the aspects we have to know, I notice replies of "why would you have to know that?" And "WTF?"

Anyway, I have been going through the meteorology section which I failed in my first exam. I passed (pretty good marks too if I do say so myself) everything except air law, meteorology, and navigation.

The Corialis effect is only ever shown as far as I can see within the northern hemisphere, and with a high pressure area at a lower latitude, moving because of pressure gradient towards a low pressure area at a higher latitude. It's tricky, being an apparent force and not an "actual" force, but I'm trying to figure out what happens when there is a high pressure more north than a low pressure, but still in the northern hemisphere?

My thinking right now is the "effect" is very much reduced, since it the pressure gradient force is moving south from a position that laterally is not changing as much, but realize I could be totally wrong.

Anyone have an answer? Anyone want to shoot me?
 
I'm definitely one that groaned.
 
45 cal, 8 mm, 12 gauge, 9 mm, 30 cal, or 20 gauge?
 
eman1200 said:
I'm definitely one that groaned.
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Just so you know, your name is on my list now!

I did a thorough search (first just subject lines with "Corialis" then a second one with Corialis anywhere in the text) on Corialis in all forums, and there were NO HITS...none, zip, nada, bupkis, null, and "don't ever search on this again".

Shame on you all! And yet you manage millions of safe takeoff, landings, cross country navigations, and manage to fly successfully in all kinds of weather.

I don't know how you could possibly do that without deep understanding of the Corialis effect north to south!

I have a feeling I, dangerously close to being banned here. Still I persist. I'm curious.
 
Clark1961 said:
45 cal, 8 mm, 12 gauge, 9 mm, 30 cal, or 20 gauge?
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Ok, you're on the list too, buddy!

My list doesn't seem to be the detrimental factor I thought it would be.

How am I expected to become a pilot without extensive knowledge of this "apparent but not actual" force on my aircraft?
 
Clark1961 said:
45 cal, 8 mm, 12 gauge, 9 mm, 30 cal, or 20 gauge?
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yup,,, i got ALL them too!

ill tell you what most of we all know about the corialis effect...
my toilet flushes counter clockwise,, ive heard they flush clockwise down under..

PS,,, my spell checker says corialis aint spelled so good,,, but then i couldnt find it in my dictionary spelled right or wrong.
so thats all i know about the corialis effect.
 
The Coriolis effect is due to the ground at the equator moving (spinning) faster than the ground further north. At the north pole it is not moving at all. The air directly above the ground tends to move at the speed of the ground (earth) below it. So if you fire an artillery shell north from the equator, the shell will carry the equator speed to the north and land to the east because the earth is spinning eastward faster at the equator than it is further north.

For some reason, (complicated), this Coriolis effect causes low pressure systems to spin counterclockwise in the northern hemisphere (and clockwise in the southern hemisphere). Now someone explain why the previous statement is true. It has to do with the fact that the wind blows towards the center of the low. Understanding that is the key to understanding the effect of the Coriolis effect on weather patterns
 
Actually, in Norway, you usually have such a situation. Look up "polar cell" in the context of atmospheric circulation. The polar cell is a high pressure system above the north and south poles. At its edges is a low pressure system which is also the boundary of the mid-latitude or Ferrel cell.
 
coloradobluesky said:
For some reason, (complicated), this Coriolis effect causes low pressure systems to spin counterclockwise in the northern hemisphere (and clockwise in the southern hemisphere). Now someone explain why the previous statement is true. It has to do with the fact that the wind blows towards the center of the low. Understanding that is the key to understanding the effect of the Coriolis effect on weather patterns
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If air moves from the equator toward the north pole and is drawn into a low, and air from the north is drawn southward into that same low, they both swerve to the right as they enter the low and end up flowing parallel to the isobars, which makes them turn counterclockwise. Air flowing out from a high also swerves to the right as it goes, and it ends up flowing closkwise.

coriolisb.gif


Coriolis only works on a large scale. The water in your toilet is affected far more by local turbulence and the way the water flows into the bowl.
 
coloradobluesky said:
The Coriolis effect is due to the ground at the equator moving (spinning) faster than the ground further north.
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Actually, the Coriolis effect is simply a result of the movement of the earth, relative to an object traveling in a straight line. It doesn’t matter whether the movement is from the equator to the north, or from the North Pole towards the equator. The course will appear to have shifted to the right, relative to the movement of the ground beneath.

In the northern hemisphere, you can imagine an overhead view of the pole with the hemisphere rotating counter-clockwise. Any straight line drawn over this will result in a path curved to the right because of that rotation.

In the south hemisphere, the polar overhead view would be clockwise rotation. Any straight line drawn there would appear curved to the left.

No “force” involved in this. Simply the relative motion of two different things. Earth and something traveling over it.
 
robert lomax said:
yup,,, i got ALL them too!

ill tell you what most of we all know about the corialis effect...
my toilet flushes counter clockwise,, ive heard they flush clockwise down under..

PS,,, my spell checker says corialis aint spelled so good,,, but then i couldnt find it in my dictionary spelled right or wrong.
so thats all i know about the corialis effect.
Click to expand...

It's a myth that toilets, and sinks, in one hemisphere swirls in a different direction than in the other. The Coriolis effect is sway too insignificant on such small objects. See: https://www.snopes.com/science/coriolis.asp

And yes, it's simply the relative motion of an object passing over the earth.
 
what if, hypothetically speaking, you were really drunk and your head was spinning to the left and you shot a gun, would it actually go in a straight line?


also, you're on a treadmill.
 
LongRoadBob said:
My thinking right now is the "effect" is very much reduced, since it the pressure gradient force is moving south from a position that laterally is not changing as much, but realize I could be totally wrong.
Click to expand...

The effect is the same whether you are going north or south. Objects and air currents are deflected to the right of their direction of motion with respect to the Earth, or to the left in the southern hemisphere.
 
Wikipedia said:
For an intuitive explanation of the origin of the Coriolis force, consider an object moving northward in the northern hemisphere. Viewed from outer space, the object does not appear to go due north, but has an eastward motion (it rotates around toward the right along with the surface of the Earth). The further north you go, the smaller the "horizontal diameter" of the Earth, and so the slower the eastward motion of its surface. As the object moves north, to higher latitudes, it has a tendency to maintain the eastward speed it started with (rather than slowing down to match the reduced eastward speed of local objects on the Earth's surface), so it veers east (i.e. to the right of its initial motion).[4][5]Though not obvious from this example, which considers northward motion, the horizontal deflection occurs equally for objects moving east or west (or any other direction).[6]
Click to expand...
 
Has noticed calmer winds at all levels with climate change versus the early 2000s
 
wow I had to look up how much daylight you are getting in Norway - 7+hours, thanks for getting me curious. Sorry, no idea about coriolis.
 
eman1200 said:
what if, hypothetically speaking, you were really drunk and your head was spinning to the left and you shot a gun, would it actually go in a straight line?


also, you're on a treadmill.
Click to expand...
Depends on whether or not it was pointed at your head...
 
WillFly4Food said:
No “force” involved in this. Simply the relative motion of two different things. Earth and something traveling over it.
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Much more than that. It's conservation of angular momentum. Air moving North is air that has been rotating at a large radius and its velocity around the pole is high. As it moves North, its radius of rotation decreases and it appears to speed up in the direction that it was already rotating: East. That's the opposite of what the "moving in a straight line" idea would tell you.

Edit: I should include this: Air near the North pole has very little velocity as it rotates with the Earth. Push it South, and its RPM, so to speak, falls off as its radius of rotation increases. So it rotates slower than the Earth, which makes it move against the Earth's rotation: it moves toward the West.

It's the same effect as the figure skater who spins on her own axis, then pulls her arms in and speeds up. A good, quick illustration here:

 
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