 One of the best climate modes that we know of is El Nino Sudden Oscillation, or ENSO. It's really important because every few years it can affect weather patterns and climate system overall. There are three phases of ENSO. Neutral phase, El Nino phase and La Niña phase. And they do all are interconnected and they can change how all the oceans in the Earth respond to it. So first of all we start looking at what normal or neutral phase ENSO is. With everything in ENSO it happens in the tropical Pacific. It has teleconnections to other places in the oceans but we will focus now in the tropical Pacific. During neutral years there's winds in the tropical Pacific that flow from America to Australasia. These winds have the peculiarity that they can move the surface of the ocean which is warm to the west. That creates this warm pool of water which in consequence generates moisture and hot air that rises up. And it creates this circulation that is called the Walker circulation. This is really important because it also fits back into keeping and maintaining this neutral phase as the winds flow from the east to the west. These great winds have the peculiarity that they will pile up this water on the western side of the tropical Pacific Ocean. And as a consequence of that they will be water rising from the deeper layers of the ocean in the east side of the tropical Pacific. And that process is known as a boiling. So now that we understand the neutral phase we'll move on into what El Niño phase represents. All El Niño phases start with a weakening of the crate winds. As soon as the crate winds weaken which means that the east to west flow of the winds decrease. This warm pool of water that was already piled up in the western side of the tropical Pacific Ocean can move now into the central Pacific or to the east Pacific. That also occurs in conjunction with the surface water in those other regions staying warm as it's now not being pushed to the west. As soon as that happens then this location where the water can affect the atmosphere changes. So if it moves to the central Pacific then hot water and humid water will rise up there. And then that will mostly mean that the precipitation in the tropical Pacific will occur within the ocean. If there's a really intense El Niño vent it can be pushed for the east and then a lot of the precipitation will happen in South America and Central America. This has a lot of consequence on how precipitation affects Australia for example in the case of really strong El Niño vents that can usually lead to really dry conditions within Australia. In addition to that this movement of hot water to the east side weakens further the water circulation and that feedbacks into this loop of staying within El Niño or within El Niño phase. In contrast El Niño phase is taking a neutral phase to the extreme in which the trade winds intensify thus they can pile up much hotter water closer to Australasia. And that has the impact of having a lot of more precipitation and rain within Australia and that's for example what we have seen this year.