File talk:Upwelling image1.jpg

A critique

• No matter who is the author, this map is wrong: Upwelling of cold waters only occurs where cold currents exist (Benguela, Humbold, California, Canarias, Western Australia, Groenlandia-Labrador and Kamchatka. Upwellig of deep waters causes two effects:
• High atmospheric pressure and clear skies (because of small evaporation being cold waters)
• Very dry climates along the coast.

What causes upwelling of cold waters?

Only the Earth's rotation causes this phenomenon:

• At the abyssal zone (the ocean's floor) water does'nt move regarding the Litosphere: both (ocean water and the earth underneath) have the same speed, similar to the Earth's rotation's speed.
• However, western coasts of the continents at the subtropical zones (actually, the continental slope) causes directly the upwelling of waters because it works like a shovel: it is not that the Earth' movement is in this zone east-westward, but is just that water is a fluid being thrown against that kind of shovel, like it happens in an artificial surfing pool. Inertia cause, in both cases, the different speed between deep and surface waters. Centripetal force acts on the ocean's abyssal zone (at the bottom), and centrifugal force prevails at the ocean surface.

The Equatorial line

• Along the Equator there is not any upwelling against what map seems to indicate. The reason is very easy: centrifugal force is maximum at the Equator, causing the Equatorial bulge, which is there more than 19 km higher than at the Poles. Consequently, water is "thrown" upward, but there is not any upwelling: water creates a bulge made with surface and warmer waters from higher latitutes (subtropical).

• Cold Currents can be deviated towards the Equator by the western coast of the continentes, as it happens with the Humboldt Current along South America. In this case, the Humboldt Current is deviated north-westwarth by the direction of Peru's coast. But this cold waters doesn't cross the Equator line just because of the equatorial bulge. Just at the Equator, cold waters from the Humbold Current meet warmer waters coming southeast from the California Current, also for different and even opposite effect of the Central American western coast.

• There are some other aspects to be discussed but I think it would be better if other users express some different ideas about use and errors of this map. --Fev (talk) 00:53, 26 September 2013 (UTC)

Is this really upwelling?

I agree with @Fev: It doesn't really seem to be upwelling. I believe this map is about phytoplankton / chlorophyll concentration, which is correlated with upwelling in zones in which it occurs. What's even more remarkable is the lack of upwelling in Portugal, literally the only place in Europe were it should be marked red and it isn't. Somalia too. Very misinformative in my opinion. Average Portuguese Joe (talk) 20:19, 21 March 2021 (UTC)