SierraCurrantBBlock

__**Arctic** **Oscillation:**__ By: Sierra Garcia

Arctic Oscillation (AO) is a large scale mode of climate variability. The Arctic Oscillation is based on winds that go counterclockwise around the Arctic. The winds must be going at at least a 55 degree northern latitude. AO has a negative and a positive phase. When the AO is in its positive phase that means there are strong winds that are confining colder air across the polar regions by circulating around the North Pole. When the AO is in its negative phase, its because the winds are more weak. Weak winds increase storms in the mid latitudes.

The Index of the AO is based on the projection of the AO loading pattern to the daily height field from the 1000 millibar height field it has to be over 20 degrees north to 90 degrees north. The AO also finds characteristics of the cold seasons based on the loading pattern.

__**El Nino/Southern Oscillation (ENSO)**__

The El Nino Southern Oscillation shows sea surface temperature in a periodic way (2-7 years). The ENSO also shows air pressure from the atmosphere across the Pacific Ocean. The Southern Oscillation shows the sea level barometric pressure between Dahiti, Australia and Tahiti. When Darwin has higher pressure, and Tahiti has lower pressure, the air goes from east to west making the westward surface water warmer and taking precipitation to Australia and the Western Pacific. The Western Pacific experiences severe drought when the pressure difference weakens. https://www.google.com/search?hl=en&q=el+nino+pics&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&bvm=bv.43148975,d.aWM&biw=1366&bih=667&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=zz8wUbiuKc7uqAG1xYDgCA#imgrc=xbfnBy0fMI0-IM%3A%3Be6EmYfIbeODWOM%3Bhttp%253A%252F%252Fwww.pmel.noaa.gov%252Ftao%252Felnino%252Fgif%252Ffst-temp-us-big.gif%3Bhttp%253A%252F%252Fwww.pmel.noaa.gov%252Ftao%252Felnino%252Fimpacts.html%3B621%3B464

Here is a video explaining El Nino more: http://www.youtube.com/watch?v=EjlIeQFxdlE

__**North Atlantic Oscillation (NAO):**__

The North Atlantic Oscillation is another way of getting data on sea surface pressure. Similar to the AO, the NAO is also an index. Unlike the AO, the NAO is based on the difference between the subtropical high and the subpolar low. When the NAO is in its negative phase, its because its based on the opposite height and pressure anomalies in the covered regions. The regions that the NAO covers are, North Atlantic, Central North Atlantic, Eastern United States, and Western Europe. When the NAO is in its positive phase, its because the sea temperature is very high and warm in the United States, and there are below average temperatures in the Greenland area. There is usually a lot of precipitation when there are above average temperatures in an area.



__**Overview AND Reflection on Chapter:**__ I thought the Chapters on weather and climate were very helpful. I had no idea there were different ways to retrieve data on sea surface pressure and other things like, sea level temperature. Now i am more aware of what it means when one of the 3 parts i had to do are in a positive or negative phase. I now fully understand what it means when there is random precipitation in my area or any area for that matter, its obviously because the patterns are either in a negative phase or positive, and thats very interesting as well.I find it extremely difficult to read the graphs from the ENSO websites, but once i watched the Youtube video it all made sense to me how to read it and how to determine each type of pattern and the different phases. I also found it very interesting how each pattern has its own characteristics and its easier to tell what those characteristics are when the data and patterns are in the negative phase. I learned a lot by doing this wikispace and it was very fun!

It was also very interesting to learn about each type of different wind and how the ENSO can determine what is indicating the pattern by the winds or pressure of the sea level. I think this job is very difficult. We watched movies in class about water and it does not seem very easy to figure out the pressure or the different characteristics that could be causing the indications on the index.

__**Profile of Scientists who discovered El Nino:**__

In the 20th century, there were two scientist who got credit for discovering the ENSO. There names were Gilbert Walker and Jacob Bejerknes. Gilbert Walker realized that there was a variation in atmospheric pressure in the 1920's.In the 1960's Bejerknes started the understanding of the ENSO by coming up with the Walker Circulation which opened up everybodys understanding of the ENSO. Later on, there were other scientists from America that helped with oceanic features. There are many scientists that should get credit for helping figure out the ENSO, but Walker and Bejerknes are the ones who opened up everybodys eyes and helped with the understandment of the ENSO.

a large body of air having characteristics of temperature, moisture, and pressure that are approximately uniform horizontally. The zone separating two air masses, of which the cooler, denser mass is advancing and replacing the warmer. a complex biotic community characterized by distinctive plant and animal species and maintained under the climatic conditions of the region, especially such a community that has developed to climax. the apparent deflection (Coriolis acceleration) of a body in motion with respect to the earth, as seen by an observer on the earth, attributed to a fictitious force (Coriolis force) but actually caused by therotation of the earth and appearing as a deflection to the right in the Northern hemisphere and a deflection to the left in the Southern Hemisphere. The El Nino Southern Oscillation shows sea surface temperature in a periodic way (2-7 years). The angular distance north or south from the equator of a point on the earth's surface, measure on the meridian of the point. The angular distance of a place east or west of the meridian at Greenwich, England, or west of the standard meridian of a celestial...: "at a longitude of 2° W"; "lines of longitude"  are the dry, cold prevailing winds that blow from the high-pressure areas the winds from the west that occur in the temperate zones of the Earth. Layered clouds belongs to a class of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves  Forests in the temperate (mild, not extreme)  an inversion is a deviation from the normal change of an atmospheric property with altitude  wind blowing steadily toward the equator from the northeast in the northern hemisphere or the southeast. The boundary of an advancing mass of warm air, in particular the leading edge of the warm sector of a low-pressure system.
 * __Vocabulary:__**
 * Air mass-**
 * cold front- **
 * biome- **
 * Coriolis effect- **
 * El Nino-Southern Oscillation(ENSO)- **
 * latitude- **
 * longitude- **
 * polar easterlies- **
 * prevailing westerlies- **
 * stratiform cloud- **
 * stratocumulus cloud- **
 * temperate forest- **
 * temperature inversion- **
 * trade winds- **
 * warm front- **