Why does el nino happen

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Paid Content How Hong Kong protects its sea sanctuaries. Apply Filter. How can climate change affect natural disasters?

With increasing global surface temperatures the possibility of more droughts and increased intensity of storms will likely occur. As more water vapor is evaporated into the atmosphere it becomes fuel for more powerful storms to develop. More heat in the atmosphere and warmer ocean surface temperatures can lead to increased wind speeds in tropical What are some of the signs of climate change?

What is the difference between weather and climate change? Weather refers to short term atmospheric conditions while climate is the weather of a specific region averaged over a long period of time. Climate change refers to long-term changes. Can major landslides and debris flows happen in all areas of the U. Landslides can and do occur in every state and territory of the U.

What is a landslide and what causes one? A landslide is defined as the movement of a mass of rock, debris, or earth down a slope. Landslides are a type of "mass wasting," which denotes any down-slope movement of soil and rock under the direct influence of gravity. The term "landslide" encompasses five modes of slope movement: falls, topples, slides, spreads, and flows. These are further What is a 1,year flood? In terms of probability, the 1,year flood has a 0. These statistical values are based on observed data.

Does an increase in the year flood estimate originate from climate or land-use change? Learn more: Flood recurrence How can a 1,year rainfall not result in a 1,year flood? It comes down to a number of factors, including the pattern of movement of the rainstorm in each particular watershed, the conditions of the soil and plant matter in the watershed, and the timing of the rainstorm in one watershed versus other watersheds. For example, if the ground is already saturated before a rainstorm, much of the rain will run How are floods predicted?

Flood predictions require several types of data: The amount of rainfall occurring on a real-time basis. The rate of change in river stage on a real-time basis, which can help indicate the severity and immediacy of the threat. Knowledge about the type of storm producing the moisture, such as duration, intensity and areal extent, which can be Filter Total Items: 6.

Year Published: U. Geological Survey natural hazards science strategy— Promoting the safety, security, and economic well-being of the Nation Executive SummaryThe mission of the U. Holmes, Robert R. View Citation. Holmes, R. For example, because the northern tier of the U.

This graph shows annual average surface temperatures gray bars , grouped by decade, from to Only two decades seem to violate the general rule: the s and the s. The eruption of Mount Pinatubo was likely to blame. Heat energy that's already present in the climate system is simply shifting back and forth between the atmosphere where it shows up in the global surface temperature value and the deeper layers of the ocean where it doesn't.

The pool of warm water grows deeper, storing excess heat at depth , and allowing for colder, deeper water to rise to the surface in the eastern half of the Pacific basin. This wind-driven disturbance creates a large area along the equator where the ocean surface temperatures are below normal. Over the span of months to seasons, heat from the atmosphere then goes into the ocean, leading to cooler air temperatures over a region broad enough to cool down the global average temperature.

Warm waters in the west Pacific Ocean slosh to the east. Now there is a large area along the equator where ocean temperatures are above normal. Heat from the ocean then goes out into the atmosphere, leading to warmer air temperatures in the Pacific and subsequently, to warmer global air temperatures plus a cascade of other impacts. All of this amounts to a shuffling of heat from one place ocean to another the atmosphere without affecting the Earth's overall energy budget—the balance between incoming and outgoing energy across the entire planet.

So unlike volcanic eruptions, which actually block energy from the Sun from reaching the surface, or solar minimums, which reduce the total amount of energy the Sun emits, the phases of ENSO are not creating or removing energy from the climate system.

Climate scientists call this kind of re-shuffling internal climate variability. Probably not. The answer depends on many factors, including where you live, how strong the event continues to be, and other climate patterns that develop and influence the seasonal outcome. Scientists have identified a set of typical U. They may happen as often as 80 percent of the time, or as infrequently as 40 percent of the time. NOAA uses a 5-category alert system for tracking ENSO that is based on a combination of observed conditions, computer model forecasts, and expert scientific judgment.

These changes in average conditions must persist for at least five overlapping three-month periods in order to be count as a full-blown episode in the historical record. The winds near the surface in the tropical Pacific usually blow from east to west.