I Sunlight refraction at sunset at different latitudes?

[Mohsin03129]

“Sunlight due to refraction is greater in higher latitudes than at the equator because of shallower angles of incidence to horizon. It takes longer for Sun to go down half a degree at sunset at shallower angles.”

When I draw a diagram of sun rays incident towards the earth, the angle appears to be the same at the equator and say at 60 degrees latitude Due to corresponding angles.

Can someone explain this statement / what am I missing ?

 

[mathman]

Did you take into account that the Earth is a ball? The path through the atmosphere is longer at high latitudes.

 

[Mohsin03129]

Did you take into account that the Earth is a ball? The path through the atmosphere is longer at high latitudes.

I understand this. That sounds like a different reasoning than the “shallow angle “ one though?

 

[mathman]

Shallow angle leads to longer path through atmosphere.

 

[Mohsin03129]

Shallow angle leads to longer path through atmosphere.

Shallow angle leads to longer path through atmosphere.

thanks, what is the best way to visualise this angle of incidence?
Is it steeper at the equator?

 

[mathman]

Outside of the equatorial zone, it is generally steeper at the equator than at higher latitudes.

 

[snorkack]

Path of sunlight is the same. Path of Sun in sky is different.
At the same latitude, the sunlight due to refraction varies due to season due to the path of Sun varying.
On equator, at equinox, Sun falls vertically from horizon to nadir, 90 degrees below horizon; at a solstice, it falls just 66 degrees below horizon. Sun on its way to travel from horizon to 90 degrees below in 6 hours spends less time between horizon and half a degree than Sun on its way from horizon to culminate 66 degrees below in 6 hours.

 

[Mohsin03129]

The only way I see the angle shallowing is if I draw a sun with parallel rays hitting earth.
The angle made by the ray with the normal to a tangent at any n-s point on the Earth surface gets shallower with increasing latitude. But surely normal to a tangent isn’t the horizon!?

I am actually not sure about the definition of Horizon here.. I was imagining the horizon to lie on the East West latitude line and the angle of incidence shouldn't change with this horizon.

 

[mathman]

Parallel rays are what happens. the Earth's diameter is around 9000 miles, while the sun is around 93 million miles away.

 

[Mohsin03129]

Parallel rays are what happens. the Earth's diameter is around 9000 miles, while the sun is around 93 million miles away.

Yes I know that

 

[Mohsin03129]

Path of sunlight is the same. Path of Sun in sky is different.
At the same latitude, the sunlight due to refraction varies due to season due to the path of Sun varying.
On equator, at equinox, Sun falls vertically from horizon to nadir, 90 degrees below horizon; at a solstice, it falls just 66 degrees below horizon. Sun on its way to travel from horizon to 90 degrees below in 6 hours spends less time between horizon and half a degree than Sun on its way from horizon to culminate 66 degrees below in 6 hours.

Path of sunlight is the same. Path of Sun in sky is different.
At the same latitude, the sunlight due to refraction varies due to season due to the path of Sun varying.
On equator, at equinox, Sun falls vertically from horizon to nadir, 90 degrees below horizon; at a solstice, it falls just 66 degrees below horizon. Sun on its way to travel from horizon to 90 degrees below in 6 hours spends less time between horizon and half a degree than Sun on its way from horizon to culminate 66 degrees below in 6 hours.

Are you referring to the northern horizon here?

 

[Mohsin03129]

Are you referring to the northern horizon here?

A diagram of these angles would be useful

Path of sunlight is the same. Path of Sun in sky is different.
At the same latitude, the sunlight due to refraction varies due to season due to the path of Sun varying.
On equator, at equinox, Sun falls vertically from horizon to nadir, 90 degrees below horizon; at a solstice, it falls just 66 degrees below horizon. Sun on its way to travel from horizon to 90 degrees below in 6 hours spends less time between horizon and half a degree than Sun on its way from horizon to culminate 66 degrees below in 6 hours.

when you say degrees below horizon , is that from the normal to a horizon?