What is the relationship and difference between offshore currents, wind sea currents, and upwellings

Offshore wind refers to the wind that blows from land to water in coastal areas. Offshore winds tend to cause seawater to move away from the coast, causing seawater to flow out of the waters it passes through and replenish the water at depth. In addition, offshore winds can cause upwelling.

Powerful prevailing winds blow from the land to the ocean, driving the surface of the seawater away from the shore, and the upper seawater is missing, except for the surrounding seawater replenishment, the seabed seawater often rises (rises) to replenish. The Peruvian cold current (upwelling) is formed under the influence of the southeast trade winds (offshore winds). The prevailing wind blows the sea surface and pushes the sea water to drift with the wind, which is the most important form of ocean current.

In addition, the upper layer of sea water drives the flow of lower sea water, forming a large-scale ocean current, which is called wind current.

The Peruvian cold snap is an upwelling caused by offshore winds.

The Peruvian cold snap is an upwelling.

1 All Peruvian cold currents are a mixture of vertically compensated and horizontally compensated currents. When the southeast trade wind blows away the sea water on the west coast of the continent, the sea water in the vacancy will be compensated vertically upwards by the middle seawater, and it will also be mixed with the sea water compensation in the horizontal direction, the direction should be mainly from south to north, because the sea water drifted by the west wind will be deflected to the north due to the geostrophic deflection force, and the sea water will be horizontally compensated from south to north due to the encounter with the mainland, but the high school textbooks have been changed back and forth in order to simplify and make it easier for everyone to understand. Therefore, the role of vertical compensation is taken as the main factor, because Peruvian fisheries are formed because of vertical compensation. Upwellings are generally caused by offshore winds.

The Peruvian cold snap is the largest because South America is much closer to Antarctica than Africa and Oceania, and the westerly drift around the Antarctic continent is blocked by South America, increasing the flow and speed. In the process of northward flow, due to the influence of geostrophic deflection forces, coupled with the prevailing southerly and southeasterly winds (offshore winds) along the coast, the surface sea water deviates westward, causing the average depth of about 100 meters of cold water in the middle layer to flood to the sea surface, and the sea temperature is very low. The average annual water temperature is generally 14° 16, which is 7° 10 lower than the surrounding air temperature, making the near-shore ocean surface cloudy and foggy, and the sunshine is weak.

Because the sea water brings a large amount of nitrate, phosphate and other nutrients, which promotes the proliferation of plankton and provides abundant food for fish, the Peruvian coast has become one of the world's famous fishing grounds.

In summary, it can be seen that upwelling is formed by the blowing of offshore winds.

There is a significant upwelling in the sea near Peru.

The ocean currents formed by the difference in wind and density reduce the sea level of the sea area from which the sea water flows out, and the sea water from the adjacent sea area flows to replenish it.

The Peruvian cold snap is formed partly by upwelling, partly by westerly winds drifting southward to the east coast of the ocean.