Perpetual Ocean by NASA [video]

by DeusExMachina • 14 years ago

54 13 14 years ago

TomGullen• 14 years ago

Great video! Here's a nooby question though, why don't the oceans settle down? Is it to do with the moon? And does this mean oceans on planets without moons are perfectly calm?

ORioN63• 14 years ago

The moon does have a effect on Earth's oceans, but the biggest reason why oceans are active, is the variation of temperature both in the atmosphere and in the water(This also creates a variation on pressure). The difference on air pressures, will create wind, which in turn create waves.

Ocean currents exist because different places on Earth are at a different temperature, and therefore the water will feel a pressure force to go elsewhere.

This is quite a generalization, but meteorology is a complex science, and there is much to dig in.

jessriedel• 14 years ago

Sure, but you didn't completely answer his question: the reason the oceans don't settle down is because the sun continuously drives these temperature gradients.

amitparikh• 14 years ago

Some currents, like the Equatorial Counter Current (NECC) (which runs West to East just North of the equator) are actually wind-driven surface currents.

emmelaich• 14 years ago

Yes it's about the wind (geostrophic currents) and temperature, but mainly because the earth doesn't stop rotating! The resultant forces are different depending on the latitude and depth. Note the dramatic differences on either side of the equator.

The most famous of these uneven forces is of course the Coriolis effect.

karamazov• 14 years ago

This has a remarkable similarity to Starry Night.

tomelders• 14 years ago

Could this be used to plot more fuel efficient shipping routes?

I know nothing about shipping routes by the way, I'm just speculating.

rmah• 14 years ago

Ocean currents have been well known and used for shipping for hundreds, if not thousands of years.

0x006A• 14 years ago

anyone knows if the data is available in a format that could be used to make a WebGL viewer out of it? would be nice to be able to spin the globe around.

libraryatnight• 14 years ago

It'd be neat to see a version of this similar to the Windmap posted earlier.

http://hint.fm/wind/

radarsat1• 14 years ago

This is very detailed, how do they make these measurements? I assume it is based on measurement but interpolated using simulation of some kind.

_delirium• 14 years ago

It's a visualization of the data produced by the ECCO2 project (http://ecco2.org/), which feeds all available measurements of temperature, current, etc. into an MITgcm fluid-circulation simulation model (http://mitgcm.org/), which then estimates the most likely circulation.

lbraasch• 14 years ago

Lots and lots of physical measurements. One large scale example is the Global Drifter Program. The US contribution is largely funded by NOAA.

http://www.aoml.noaa.gov/phod/dac/index.php

The array is usually maintained at above 1000 discrete instruments deployed by various cargo ships, and research vessels globally. These measure ocean currents centered at 15m depth, which helps eliminate bias from surface currents driven by winds. These drifters also measure surface temperature some with sea level air pressure.

Perpetual Ocean by NASA [video]

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