18 votes
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Great Pacific Garbage Patch Equilibrium Points

Yes, you're right, there should be (at least one) saddle point in the middle of the loop. And indeed, if you search for illustrations of Pacific ocean circulation, you can see the saddle point in ...
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18 votes

Great Pacific Garbage Patch Equilibrium Points

Theoretically, I agree that there should be one instable equilibrium point between the two stable equilibrium points when we have a 2D current field. However, there are some additional components of ...
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13 votes
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How authentic was the movie scene in "The day after tomorrow" related to the understanding of the north Atlantic current system?

I'm not sure how much I can comment about it, but here we go (that's a joke... maybe). Is it realistic in the collapse of the current system? Well kind of, but not in the timespan that is suggested. ...
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12 votes
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Is there a way to find the direction to land in the middle of an ocean?

Your best bet without modern tools would be a sextant and the proper maps for celestial navigation. This is a time-tested and old method of navigation no longer in regular use, but it probably doesn'...
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12 votes
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Forecasting oceanic rogue waves

There are few known mechanisms that lead to the generation of Rogue waves, such as the ones you mentioned, but essentially all Rogue waves are the due to the nonlinear wave dispersion characteristics ...
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12 votes
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What visual wave behaviour help to tell if a tide is going in or out?

As SimonW points out strong tidal currents will modify the wave shape and significant height. The Wolf & Prandle (1999) study provides a neat summary description of the effects of currents (of ...
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10 votes
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Does bathymetry affect ocean topography/height?

Oceanic topography of the sea surface $\zeta$ can be defined as the height of the sea surface relative to a particular level surface, the geoid. The geoid to be the level surface that coincided with ...
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10 votes

Why is ocean surface velocity around 3% of wind velocity?

A very good analysis looking at the 3% relationship is an article by Weber (1983). His main result is that: We assume a fully developed sea, and take the eddy viscosity to be proportional to the ...
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  • 14.7k
10 votes
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What causes these odd-looking currents in the Tasman Sea?

Great question. These features are mesoscale Eddies and they are akin to hurricanes in the atmosphere. They are the ocean’s high or low pressure systems and are the result of instabilities. The ...
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9 votes
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Why is Somalia so dry?

Somalia's dryness despite it's proximity to the equator (which should provide ample opportunities for year round rainfall) has perplexed most meteorologists. In this following answer we will try to ...
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  • 6,277
8 votes

Thermohaline: Why is cold and dense seawater salty when warm water holds more dissolved salts?

Warm water does hold more salt - at saturation, but seawater isn't even close to saturation. Surface sea water gets warm, starts to evaporate (hence clouds) and therefore gets denser. So it sinks to ...
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8 votes
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What is the weather data covering the range of 359 to 360 degree

Remember that 360° == 0°. They're the same line of longitude. So the gap between 359° and 0° is no more than the gap between 1° and 2°, and should be handled the same way.
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7 votes

How stable is the Gulf Stream? Could it stop suddenly?

In some capacity, differential heating is responsible for convective motion of the ocean due to buoyant forces. However, it is possible to show that the net (vertically integrated) horizontal ...
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7 votes

How stable is the Gulf Stream? Could it stop suddenly?

There's a pretty good rundown of this issue over at RealClimate, and a wikipedia article dedicated to the topic. A summary of the main points from there: The Gulf Stream is part of the Meridional ...
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7 votes

How to measure ocean vertical velocity?

Direct measurements of three-dimensional ocean currents are carried out with acoustic Doppler current profilers (ADCPs). The ADCPs are usually moored and bottom mounted instead of being ship-based or ...
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  • 14.7k
7 votes
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How is the distribution of Argo floats managed over the Earth's oceans?

I think, there are two factors which prevent the forming of clusters of floats: The floats' lifespan. Batteries supposedly last for four years, then the floats become debris which sink to the bottom ...
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  • 786
7 votes

What goes into a tide power prediction for every fifteen minutes over the next twenty five years?

Tide prediction at some locale is more of an empirical art rather than an analytic science. It essentially is a reduction of decades or centuries of historical tide levels at the locale to Fourier-...
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6 votes
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What are the effects of underwater "windmills"?

As you have noted, this technology is new, and so far only small numbers of experimental tidal energy converters (TECs) have been deployed. For this reason, little has been possible in the way of ...
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6 votes
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ocean current frequency

Ocean currents can be described as flow oscillations that are forced at different frequencies. In the absence of any external forces (wind, friction), the resulting flow is the inertial motion, which ...
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  • 14.7k
6 votes

Odd structures in 66 year NCEP daily temperature reanalysis

It looks like a Gibbs oscillation, a basic feature of spectral analysis. In a spectral atmospheric model this means that near high orography artificial surface waves exist which may reflect in ...
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  • 318
6 votes
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What is the area with the largest velocity vertical shear in the ocean?

Areas associated with velocity shear at a stratified interface are notably strong in the region of the Equatorial Undercurrent, straits (ex: strait of Gibraltar, the Bosphorus) and regions of the ...
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6 votes

If a ship on its way to Germany from Norway sank, where will the survivors likely end up?

The survivors would probably end up in Jutland or Norway, maybe Sweden due to the currents. CC BY-SA 3.0 The main wind pattern is also western, but with prevailing eastern winds, they might end up ...
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  • 5,896
6 votes

What is the (average) velocity of ocean currents?

This is not meant to be a comprehensive answer: Sometimes the easiest way to calculate the velocity of an ocean current is to take the published transport of the current and divide by the total depth ...
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5 votes
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Is there conclusive evidence for the Antarctic Circumpolar Current developing after the glaciation of Antarctica?

Lyle et al. (2007), prior to the paper you mention, also came up with this idea that the ACC initiated with its modern setting (i. e. with strong currents and mixing throughout the water column) ...
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  • 5,278
5 votes
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What is the relationship between Ekman transport and Ekman pumping?

The link is the conservation of mass equation: $$ \frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial z} = 0. $$ Briefly, Ekman pumping is the horizontal ...
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  • 66
5 votes
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Difference in surface temperature between the Northwest Atlantic and Northeast Atlantic

The main reason is that the Gulf Stream transports warm surface water from the tropics, driven by the thermohaline circulation. The tropical trade winds push surface water towards Western Atlantic and ...
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  • 5,896
5 votes

Land's effect on winds and currents?

A few thoughts - assuming like you say that the aqua-planet is the same size as earth, and all else being equal, it's best to consider the two major classes of waves: Nondispersive wind generated ...
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  • 422
5 votes

Thermohaline current in North Atlantic

Complementary to the points about salinity emphasised by TomO and S Verhoef, one more point to emphasise is the role of deep ocean convection. You may have in mind this picture of water sinking ...
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5 votes

If a prevailing wind traveled due east in the Northern Hemisphere, would the Coriolis Effect act on the water?

The Coriolis Effect occurs in all directions equally, even straight zonal (east-west) winds. Many indeed struggle with this idea - this Physics SE question has a fair explanation as to why. As ...
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4 votes

What causes these odd-looking currents in the Tasman Sea?

I'm posting this as an answer rather than a comment to expand a bit on the excellent answer from Isopycnal Oscillation and note some minor differences I observed. I had actually looked for ...
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