Trade Winds:
The Trade Winds are a part of the global wind pattern, which is divided into three wind belts. (1) Polar Easterlies: 60-90 degrees N and S. (2) Prevailing Westerlies: 30-60 degrees N and S, (Westerlies). (3) Tropical Easterlies: 0-30 degrees N and S, (Trade Winds).
Above is a diagram of the global wind patterns and the direction in which the wind blows in the different belts. The Trade Winds (between 30N and 30S) blow from the East to the West. During an El Niņo, the trade winds slacken, causing upwelling to shut off, which leads increased ocean temperature.
Coriolis Effect:
The Coriolis effect is a force which deflects air and wind, from its path. This force is the result of the earth's rotation.
In the above image, you can see that objects in the northern hemisphere deflect to the right, while objects in the southern hemisphere deflect to the left. The famous example of this is flushing a toilet bowl. In the northern hemisphere, the water will always drain clockwise, while in the southern hemisphere it will always drain counter-clockwise.
Upwelling:
Upwelling,
in relating to ocean dynamics, is the upward motion of
sub-surface water towards the surface of the ocean.This is often
the source of cold, nutrient rich water. Strong upwelling occurs
along the equator where easterly winds are present.Upwelling can
occur along coastlines, and is extremely important for fishing
along California and
Peru.
Now look closely at the above image. The diagram shows that as the surface water is being pushed away from the coast,this water is being replaced with sub-surface water. This water is cooler than the surface water. These conditions described are present in non El Niņo years. During an El Niņo, the surface water is not displaced as much, and upwelling of cold water shuts off.
Positive Feedback:
In Positive Feedback, the change to the system is always increased. Whereas negative feedback keeps systems at current levels, positive feedback causes systems to break down. A thunderstorm is an example of positive feedback.As sunlight evaporates water, warm moist air rises. This air condenses to form clouds, which causes heat to be released. Warm air rises further, forming thunderheads. Updrafts cause rain, hail, and lightning.As more air rise, more water condenses, creating more energy in the system. This is positive feedback.There is little difference between this and El Nino. All positive feedback process cannot last forever. Once all its energy is spent, the system ends, but the larger system continues to function.
Negative Feedback:
In negative feedback, the change to a system is always reduced. Negative feedback tends to maintain systems at proper working levels. An example of negative feedback is sweating. As your body heats up, your sweat glands in your skin to open and release water. The evaporation of sweat carries heat away, which cools your body. When your body no longer needs to discharge heat, your pores close, and your skin returns to normal. In this way, your body temperature is maintained within a range not dangerous to your body.
Lake Effect Snow:
Lake effect snow occurs when a mass of cold air moves over a body of warmer water. This causes clouds to build over the lake and eventually develop into snow showers as they move downwind. The most likely setting for lake effect snow is when Arctic air rushes over the warmer water of the Great Lakes during winter. Because of the west or northwest direction of the wind, lake effect snow tends to fall on the east or southeast sides of lakes. Besides the Great Lakes, the only other lake that produces significant lake effect snow in the US is the Great Salt Lake in Utah.