Wind - from, current - to

[Genady]

Why are the directions of wind and current designated in an opposite way, as in "Northern wind" vs. "Northern current"?

[StringJunky]

Here we say "Northerly, Westerly, Easterly, Southerly". The convention seems to name them where they come from i.e. the source.

[exchemist]

54 minutes ago, Genady said:

Why are the directions of wind and current designated in an opposite way, as in "Northern wind" vs. "Northern current"?

Wind direction is specified according to the direction it comes from, as that is what you feel on your face and how you relate to the wind to set your sails and steer your vessel. I couldn't quickly find a reference to a "northern current", but I imagine it might make sense to refer to that according to the direction in which it causes your vessel to drift. 

[Genady]

45 minutes ago, StringJunky said:

Here we say "Northerly, Westerly, Easterly, Southerly". The convention seems to name them where they come from i.e. the source.

Winds but not currents, AFAIK. For example, (Sea current direction @ Windy Community)

Quote

In the nautical world the sea current direction is named as:

The direction of ocean currents is the direction they're headed for or where the current is flowing towards, and the direction of wind is named as the direction from where it's blowing. So an easterly current and westerly wind is going the same way or has the same vector - from west to east, but is named differently.

 

[TheVat]

25 minutes ago, exchemist said:

Wind direction is specified according to the direction it comes from, as that is what you feel on your face and how you relate to the wind to set your sails and steer your vessel. I couldn't quickly find a reference to a "northern current", but I imagine it might make sense to refer to that according to the direction in which it causes your vessel to drift. 

That sounds about right.  Water, for humans, is all about where it is flowing to.  A river or stream flows south, it isn't a "northerly stream."  Maybe earliest human experiences were with freshwater, simple rafts on water flowing between banks, where the concept is very clear.  With wind, otoh, it matters where it comes from - north wind brings cold, south wind brings milder temps, west wind (in a particular area) might bring more rain, or dust, or distant sea air.

[Sensei]

Winds and ocean currents can flow in different directions depending on the altitude or depth of the water.

 

Note that the "red" currents overlap with the "blue" currents.

[exchemist]

1 minute ago, Sensei said:

Winds and ocean currents can flow in different directions depending on the altitude or depth of the water.

 

Note that the "red" currents overlap with the "blue" currents.

Irrelevant to the thread question.

[Genady]

1 hour ago, exchemist said:

Wind direction is specified according to the direction it comes from, as that is what you feel on your face and how you relate to the wind to set your sails and steer your vessel. I couldn't quickly find a reference to a "northern current", but I imagine it might make sense to refer to that according to the direction in which it causes your vessel to drift. 

 

31 minutes ago, TheVat said:

That sounds about right.  Water, for humans, is all about where it is flowing to.  A river or stream flows south, it isn't a "northerly stream."  Maybe earliest human experiences were with freshwater, simple rafts on water flowing between banks, where the concept is very clear.  With wind, otoh, it matters where it comes from - north wind brings cold, south wind brings milder temps, west wind (in a particular area) might bring more rain, or dust, or distant sea air.

Let it be "hypothesis 1". Here is "hypothesis 2":

From an everyday physical experience, air needs to be blown in order to make it move, i.e., its direction is determined by its source. Water, OTOH, flows by itself, e.g., downhill or towards the ocean, i.e., its direction is determined by its destination.

[swansont]

Owing to dispersion/diffusion/dissipation, wind has a better defined source than sink and water flow in rivers generally has a well-defined sink, but not source. Makes sense the direction would be in terms of the component that’s more clearly known.

[Genady]

Just now, swansont said:

Owing to dispersion/diffusion/dissipation, wind has a better defined source than sink and water flow in rivers has a well-defined sink, but not source. Makes sense the direction would be in terms of the component that’s more clearly known.

Yes, this is the "hypothesis 2" above. (I guess we cross posted.)

[Sensei]

24 minutes ago, Genady said:

From an everyday physical experience, air needs to be blown in order to make it move, i.e., its direction is determined by its source. Water, OTOH, flows by itself, e.g., downhill or towards the ocean, i.e., its direction is determined by its destination.

As I mentioned in a previous post, the ocean does not follow this rule. This happens only in rivers, and in very simplified version, where water flows from a higher altitude to a lower one. Ocean water has different densities at different depths, and underwater currents can flow in opposite directions. The same is with wind vs altitude.

2 hours ago, Genady said:

Why are the directions of wind and current designated in an opposite way, as in "Northern wind" vs. "Northern current"?

Semantics.

 

The water in North Atlantic Current flows from south to north and then turns around from north to south.

https://en.wikipedia.org/wiki/North_Atlantic_Current

 

Edited February 10 by Sensei