Nnel nino southern oscillation pdf files

The role of drought and climate change in the syrian uprising. We examine whether the unified oscillator is a good representation of enso. Observations of the tropical pacific ocean during a normal year the national oceanographic and atmospheric administration noaa maintains several laboratories around the country for specialized atmospheric and oceanic research. A record of the southern oscillation index for the past. Easterly winds over the eastern and central equatorial pacific cause oceanic. Merri eld department of physics, yale university, new haven, ct 06520 advisor. The term coupled means that the atmosphere and ocean work in harmony with one another. The clearest sign of the southern oscillation is the inverse relationship between surface air pressure at two sites. Terms in this set 11 high pressure and sinking air dominates the coastal region of south america, which produces clear, fair, and dry weather. A record of the southern oscillation index for the past 2,000 years from precipitation proxies hong yan, liguang sun, yuhong wang, wen huang, shican qiu, chengyun yang this file includes. Year djf jfm fma mam amj mjj jja jas aso son ond ndj. The various cold and warm patches of ocean water act to cool or heat the atmosphere, influencing global climate patterns.

Twothirds of global cropland area impacted by climate. What links here related changes upload file special pages permanent link page information wikidata item cite this page. Enso represents a coupled mode of the ocean and atmosphere, which is to say that the atmosphere influences the ocean primarily through. By this point in the course the students should have a good understanding about how density differences drive motion in both the atmosphere and ocean. Nat geo reading questions use your readings and the video to answer these write the letter of the matching description after the numbered term 1. The southern oscillation describes a bimodal having two peaks or modes. Nov 10, 2016 this discussion is a consolidated effort of the national oceanic and atmospheric administration noaa, noaas national weather service, and their funded institutions. These episodes alternate in an irregular interannual cycle called the enso cycle. On the other side of the pacific, a lowpressure region and rising air creates cloudy conditions and lots of rain in indonesia, new guinea and northern australia.

National oceanic and atmospheric administration, seattle, wa, usa. The oni is calculated by averaging sea surface temperature anomalies in an area of the eastcentral equatorial pacific ocean, which is called the nino 3. The southern oscillation is the accompanying atmospheric component, coupled with the. The haze pollution over eastern china has evident interannual variability. We have already seen an example of a natural mode of climate variability above in the amo. These warmer or cooler than normal ocean temperatures can affect weather patterns around the world by influencing high and low pressure systems, winds, and precipitation. Get a printable copy pdf file of the complete article 1. They often begin to form during juneaugust, reach peak strength during decemberapril, and then decay during mayjuly of the next year. Southern oscillation index soi teleconnections national. This component is an oscillation in surface air pressure between the tropical eastern and the western pacific ocean waters. These patterns shift every 27 years, disrupting largescale flow of air in the tropics that triggers a cascade of global side effects.

This lab, and the topic of enso in general, comes after labs and lectures on atmospheric circulation and ocean circulation. Climate prediction center cpcoceanic nino index data. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The strength of the southern oscillation is measured by the southern oscillation index soi. The complete table going back to djf 1950 can be found here. The soi is one measure of the largescale fluctuations in air pressure occurring between the western and eastern tropical pacific i. Pdf any assessment of future climate change requires knowledge of. The oni is calculated by averaging sea surface temperature anomalies in an area of the eastcentral equatorial pacific ocean, which is called the nino. However, some prolonged episodes have lasted 2 years and even as long as 34 years. B corresponding time series of the southern oscillation index, normalized tahiti minus darwin pressures, in standardized units, along with a decadal smoothed curve.

Here we provide a synopsis of our current understanding of the spatiotemporal complexity of this important climate mode and its influence on the earth system. For more color images from trenberth and caron, 2000, click. The southern oscillation index soi is a standardized index based on the observed sea level pressure differences between tahiti and darwin, australia. Over periods of a month or longer, higher pressure than normal at one site is almost always concurrent with lower pressure at the other, and vice versa. The southern oscillation index soi is a measure of the intensity or strength of the walker circulation. During the last two decades, with the availability of rainfall.

Geofile online april 2008 569 paul warburton impacts of. Southern oscillation, in oceanography and climatology, a coherent interannual fluctuation of atmospheric pressure over the tropical indopacific region. The southern oscillation entails a largescale pressure seesaw, on a time scale of 210 years, and with dipoles over the eastern south pacific and the greater indonesianaustralasian region, but spanning the global tropics. The most intense enso activity within the reconstruction occurred. Southern oscillation an overview sciencedirect topics.

Eastwardmoving atmospheric and oceanic waves help bring the cold water to the surface. It can be explained in neither strictly oceanographic nor strictly meteorological terms. Climate prediction center southern oscillation index links. The connection between earths oceans and atmosphere has a direct impact on the weather and climate conditions we experience. This needs to be recognized for scientific uses, and precision can only be achieved if the. Evidence show that southern africas climate is influenced by. Darwin, australia, and the south pacific island of tahiti.