Does the atmosphere change first in an ENSO event and
then change water temperature (ocean-air hypothesis) or does the water
circulation change, causing the temperature to change thereby creating
changing weather patterns (ocean-ocean hypothesis)? Unfortunately,
physical oceanographers and meteorologists are still debating this.
These two models try to explain why El Nino causes increased water
temperatures off North America.
All scientists agree that El Nino does cause
drastic changes in the biological community, but some scientists blame
more disasters on El Nino than others. To resolve this debate scientists
are still analyzing data. Understanding this cycle might give us
warnings so we can expect an El Nino before it arrives. This can prepare
countries to expect abnormal weather patterns. Already they have
determined that stronger than average easterlies in the west
equator at least 18 months, signals an approaching El Nino. Also sea
level (the height of water is not all one level) is unusually higher in
the west than in the east Pacific and a larger layer of warm water in
the west Pacific warns oceanographers that an ENSO event is coming.