Do sea currents change?

Question

the currents in the sea... do they ever change? does anyone know?

Answer 1

Based on the wind current's caused by the moon's gravity known as the ebb tide.

Answer 2

yes, they do change... the last ice age was caused by a massive glacial lake being instantaneously drained into the sea, when its walls collapsed (most likely due to an earthquake). The ensuing cooling effect caused one of the main oceanic currents (that takes warm water from the equatorial zones, to the northen zones) to shut down. I am not sure which current it was... but it put the world into an ice age =]

Answer 3

Yes they do. El Nino is a classic example. El Niño is translated from Spanish as "the boy child". Peruvian anchovy fishermen traditionally used the term - a reference to the Christ child - to describe the appearance of a warm ocean current off the South American coast around Christmas. Over the years the term El Niño has come to be reserved for the sequence of changes in the circulation across the Pacific Ocean and Indonesian archipelago when warming is particularly strong. Approximately 14 El Niño events affected the world between 1950 and 2003. Amongst them was the 1997/98 event, by many measures the strongest thus far this century, although South Africa escaped the impact of it to some extend.

La Niña, Spanish for "the girl", is the opposite of El Niño. SSTs in the equatorial Pacific become cooler than normal, giving rise to the term "cold event". This situation is reflected by negative SST anomalies. The Walker circulation intensifies and the SOI consequently becomes positive during this event.

The changes in the Pacific Ocean are represented by the term "El Niño/La Niña", while changes in the atmosphere are known as the "Southern Oscillation". Because these two cannot be separated, the term ENSO is often used. ENSO refers to both El Niño and La Niña.

Answer 4

all the time

Answer 5

Currents and winds are deflected by Coriolis forces. The surface currents are driven by wind blowing over the ocean's surface. Where winds blow predictably, these currents are predictable also their associate climates. Wind-driven currents depend on the vagaries of climate and climate depends on ocean currents.

Scientists measure the barometric difference between east and west side of the South Pacific and call it the ENSO index (El Niño Southern Oscillation). It is only a very small symptom of a very large system. From this index, many, often too far reaching, conclusions are drawn. The El Niño cycle used to be strong, in twenty year intervals, but recently it has become weak with more frequent intervals. Such change may have been caused by human influence on the atmosphere. In a warming world, strong ocean currents are needed to spread the extra heat evenly.