La Nina Weather Pattern to Continue Through to mid 2010

[sharon sanders]

LA NINA CONDITIONS ARE LIKELY TO CONTINUE THROUGH SPRING AND ARE CONSIDERED
THROUGH MJJ. INCREASED CHANCES FOR ABOVE-AVERAGE TEMPERATURES CONTINUE TO BE
FORECAST FOR THE SOUTHWEST, SOUTHERN ROCKIES AND PARTS OF THE SOUTHERN PLAINS
THROUGH JJA AND ARE INDICATED BY MOST STATISTICAL AND DYNAMICAL FORECAST TOOLS.
DRY SOIL MOISTURE CONDITIONS CONTINUE TO PLAY A ROLE IN THE OUTLOOK ACROSS
PORTIONS OF THE SOUTHERN PLAINS DURING THIS PERIOD. BELOW-AVERAGE TEMPERATURES
ARE EXPECTED TO PERSIST FOR COASTAL AREAS OF ALASKA INTO THE AMJ AND MJJ 2009
SEASONS DUE TO COOLER-THAN-AVERAGE SSTS, AND POSSIBLE LINGERING OF COLD LA
NINA/PDO CONDITIONS.

http://www.cpc.ncep.noaa.gov/products/predictions/90day/fxus05.html

</pre>

[Michael Coston]

Re: La Nina Weather Pattern to Continue Through the Summer 2009

Some acronym help.

AMJ = April May June

MJJ = May June July

JJA = June July August

PDO=Pacific Decadal Oscillation

[sharon sanders]

Re: La Nina Weather Pattern to Continue Through the Summer 2009

Please see this thread:


Outbreak of the El Nino Maybe a Precursor to Influenza Pandemic

http://www.flutrackers.com/forum/showthread.php?t=91678

[tropical]

Re: La Nina Weather Pattern to Continue Through the Summer 2009

Please see this thread:

Outbreak of the El Nino Maybe a Precursor to Influenza Pandemic

http://www.flutrackers.com/forum/showthread.php?t=91678

thread texts:

"Comprehensive data years 1890-2004, we can get influenza pandemic 6 climate features: Madre at its borders during the cold phase; the previous year or the first two years of moderate intensity for more than La Nina years; 50-70 during the 20th century At the same time, China's strong sandstorm years; before and after a year or year for the cold summer in Northeast China year (50-70 during the 20th century at the same time as serious cold damage years); was more than moderate intensity for El Nino years; year sunspot Valley for years, or m peak in M, m-1-year, m +1 or M +1 years. 1889-1890 years, in 1900 ,1918-1919 ,1957-1958 1968-1969 and 1977 bird flu outbreak are to meet this condition 6, At the same time, since 1890 to meet this condition, only 6 more than 6 times the outbreak of [4-6]."

"2011,2015,2018-2019 was possible El Nino years ,2013-2014 ,2016-2017 was a possible La Nina years, the 2009 La Nina and El Nino may be converted in"

Converted in what?
The above assumed the presence of Nino and Nina at the same time (at diferent places), but they oscilate one after the other.

Apart that in the above text cited the 1890-2004 period with 6 climate features, appeared many diferent variables, ex. not only cold and sunspots, but sandstorms, and that the anomalies named El Nino and El Nina 100 years ago were probably diferent than their actual more heavily manifestations.
So Could we join all this and flu with only El Nino / La Nina?


http://en.wikipedia.org/wiki/El_Ni%C3%B1o-Southern_Oscillation
El Ni&#241;o-Southern Oscillation

From Wikipedia, the free encyclopedia


Jump to: navigation, search
<!-- start content -->For other uses, see El Ni&#241;o (disambiguation).

Average circulation in the south Pacific Ocean


El Ni&#241;o-Southern Oscillation (ENSO; commonly referred to as simply El Ni&#241;o) is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Ni&#241;o and La Ni&#241;a are important temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The name El Ni&#241;o, from the Spanish for "the little boy", refers to the Christ child, because the phenomenon is usually noticed around Christmastime in the Pacific Ocean off the west coast of South America.<SUP class=reference id=cite_ref-DFG_0-0>[1]</SUP> La Ni&#241;a, similarly, means "the little girl". These effects were first described in 1923 by Sir Gilbert Thomas Walker from whom the Walker circulation, an important aspect of the Pacific ENSO phenomenon, takes its name. The atmospheric signature, the Southern Oscillation (SO) reflects the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin, Australia. The most recent occurrence of El Ni&#241;o started in September 2006<SUP class=reference id=cite_ref-Pastor2006_1-0>[2]</SUP> and lasted until early 2007.<SUP class=reference id=cite_ref-Borenstein2007_2-0>[3]</SUP> From June 2007 on, data indicated a weak La Ni&#241;a event, strengthening in early 2008 and weakening in late 2008, with a forecast return to neutral conditions in 2009.
ENSO is associated with floods, droughts, and other disturbances in a range of locations around the world. These effects, and the irregularity of the ENSO phenomenon, makes predicting it of high interest. Significant advances in the predictability of ENSO were contributed by Stephen Zebiak and Mark Cane.<SUP class=reference id=cite_ref-3>[4]</SUP> ENSO is the most prominent known source of inter-annual variability in weather and climate around the world (about 3 to 8 years), though not all areas are affected. ENSO has signatures in the Pacific, Atlantic and Indian Oceans.
During major warm events, El Ni&#241;o warming extends over much of the tropical Pacific and becomes clearly linked to the intensity of the Southern Oscillation. While ENSO effects are basically in phase between the Pacific and Indian Oceans, ENSO effects in the Atlantic Ocean lag behind those in the Pacific by 12 to 18 months. Many of the countries most affected by ENSO are developing countries that are largely dependent upon their agricultural and fishery sectors for food supply, employment, and foreign exchange.
New capabilities to predict the onset of ENSO events can have global socio-economic impacts. While ENSO is a natural part of the Earth's climate, an important concern is whether its intensity or frequency may change as a result of global warming. Low-frequency variability has been evidenced; interdecadal modulation of ENSO from the Pacific Decadal Oscillation (PDO) or the Interdecadal Pacific Oscillation (IPO) might exist. This could explain the so-called protracted ENSO of the early 1990s.

[tropical]

Re: La Nina Weather Pattern to Continue Through the Summer 2009

Thanks Florida, and salutations to Snowy.


#5: "But Ben Giese of Texas A&M University said complex computer modelling showed the 1918 El Nino event was almost as strong and occurred before there was much global warming caused by the burning of fossil fuels or widespread deforestation."
...
"For 1918, the simulation produced a strong abnormal surface warming in the central Pacific and weaker warming nearer the South American coast."


It we'll be seen, but who knows if all of the possible relevant influencing items were recorded that times (1918) and now used to feed this modelling process.

Other events could had influxed this strong 1918 El Nino, in example:
there were many volcano eruptions in the above epoque,
maybe they also influenced a change in the normal central Pacific surface warming, without a need for an global warming to be present.

Additionaly, can we realy said for that time that it wasn't already present an widespread deforestation and burning, not devastating as on today esigue remaining forest patches, but in the era of wood and coal energy ...

[Sally Furniss]

New ?flavour? of El Nino under global warming

Research published today in Nature has identified a new type of El Ni?o climate anomaly that is occurring with more and more frequency as a consequence of human-induced global warming. In the classic El Ni?o pattern, weak trade winds lead to unusually ?

24/09/09


El Ni?o ?Modoki? ? a new kind of El Ni?o will increase with global warming
Research published today in Nature has identified a new type of El Ni?o climate anomaly that is occurring with more and more frequency as a consequence of human-induced global warming.
In the classic El Ni?o pattern, weak trade winds lead to unusually warm surface sea temperatures in the tropical eastern Pacific. In the altered El Ni?o, a region of warm ocean in the central Pacific is flanked on the east and west by unusually cool waters. This new pattern has been dubbed El Nino ?Modoki? ? a Japanese word meaning ?similar, but different?.
The researchers, led by Sang-Wook Yeh of the Korea Ocean Research & Development Institute conclude that the new type of El Ni?o will happen five times more often by the end of this century. They expect it to cause major shifts in global climate patterns, including more effective forcing of droughts in Australia and India.
We asked scientists to comment on the significance of this news for New Zealand and our global understanding of climate trends.
Dr Brett Mullan, Manager of the Climate Variability Group at NIWA comments:
?There is an ongoing debate in the scientific literature about whether global warming will lead to more ?El Nino-like? circulation changes in the Pacific or not. However, when assessing impacts it is even more important to recognise that not all El Ninos are the same and can produce different climatic responses in countries around the Pacific rim such as New Zealand. The Yeh et al paper (Nature, 2009) essentially addresses this second aspect and provides evidence that El Nino ?Modoki? events will become more common in future.
?The word ?Modoki? is a Japanese term to describe something that is ?similar but different?, and was first introduced to explain the unusual climate anomalies experienced in Japan in the 2004 El Nino, but the term has only became widely known internationally since 2007. A Modoki El Nino has the maximum sea surface warming in the central equatorial Pacific as opposed to the eastern Pacific (the ?classical? El Nino). Modoki El Ninos have become more common since 1990, and other recent research suggests the associated rainfall and temperature anomalies are slightly different for Australia and New Zealand than for the classical eastern Pacific El Nino.
?So this new study suggests useful avenues of research on future New Zealand climate variability. For example, we know that El Ninos substantially reduce the likelihood of a tropical cyclone affecting New Zealand as it exits the tropics into mid-latitudes. But we don?t know how Modoki El Ninos differ from classical El Ninos in this regard.?
Dr James Renwick, Principal Scientist, Climate Variability & Change, NIWA comments:
?The paper by Yeh et al provides some very interesting dynamical insights into the changing nature of the El Nino cycle under climate change, showing how weakening trade winds combined with changes in the temperature structure of the Equatorial Pacific Ocean could lead to El Nino events preferentially being centred farther west.
?It is a welcome addition to the literature, as there has been much uncertainty about the future of El Nino as the background climate changes. El Nino plays such an important role in modulating year-to-year climate variations in different regions (such as New Zealand), it is vitally important to understand how the El Nino cycle will change in the future.?

http://pacific.scoop.co.nz/2009/09/new-flavour-of-el-nino-under-global-warming/

[Sally Furniss]

Re: La Nina Weather Pattern to Continue Through the Summer 2009

What is El Ni?o?

El Ni?o is a natural feature of the global climate system. Originally it was the name given to the periodic development of unusually warm ocean waters along the tropical South American coast and out along the Equator to the dateline, but now it is more generally used to describe the whole "El Ni?o - Southern Oscillation (ENSO) phenomenon", the major systematic global climate fluctuation that occurs at the time of the ocean warming event. El Ni?o and La Ni?a refer to opposite extremes of the ENSO cycle, when major changes in the Pacific atmospheric and oceanic circulation occur.
When neither El Ni?o nor La Ni?a are present, (usually referred to as "neutral" or normal conditions), trade winds blow westward across the Pacific, piling up warm surface water so that Indonesian sea levels are about 50 cm higher than those in Ecuador. Cool, nutrient-rich sea water "wells up" off the South American coast, supporting marine ecosystems and fisheries. Relatively cold sea temperatures also extend along the equator from South America towards the central Pacific. High rainfall occurs in the rising air over the warmest water to the west, whereas the colder east Pacific is relatively dry.
During El Ni?o, the trade winds weaken, leading to a rise in sea surface temperature in the eastern equatorial Pacific and a reduction of upwelling off South America. Heavy rainfall and flooding occur over Peru, and drought over Indonesia and Australia. The supplies of nutrient rich water off the South American coast are cut off due to the reduced upwelling, adversely affecting fisheries in that region. In the tropical South Pacific the pattern of occurrence of tropical cyclones shifts eastward, so there are more cyclones than normal in areas such as the Cook Islands and French Polynesia.
During La Ni?a events, the trade winds strengthen, and the pattern is a more intense version of the "normal conditions", with an even colder tongue of sea surface temperatures in the eastern equatorial Pacific.
<table> <tbody> <tr> <td></td> <td></td></tr> <tr> <td> Normal Tropical Pacific Conditions
</td> <td> Tropical Pacific Conditions during El Ni?o
</td></tr></tbody></table>
A more detailed explanation of El Ni?o, including diagrams showing the ocean ? atmosphere interactions described above, is available on the NOAA website
The Southern Oscillation Index (SOI) is calculated from the pressure difference between Tahiti and Darwin. Anomalously low values of this index correspond to El Ni?o conditions, while the opposite conditions with an anomalously high SOI value are called La Ni?a episodes. El Ni?o events occur about 3 to 7 years apart, typically becoming established around April or May and persisting for about a year thereafter.

A Plot of Southern Oscillation Index (SOI) derived from pressure measurements at Tahiti and Darwin. The negative excursions in red include the El Ni?o events of 1982?83, 1986?87, 1991?94, 1997?98 and 2001-2003.
Some researchers have suggested the frequency (and perhaps intensity) of El Ni?os will be affected by climate change resulting from continuing enhanced anthropogenic greenhouse gas emissions. However, there is as yet no scientific consensus on this issue, or on whether the relatively higher frequency of El Ni?os over the last two decades is related to the slow rise in global temperatures this century. This is discussed further on NIWA?s Global Climate Models web page.

http://www.niwa.co.nz/our-science/climate/information-and-resources/clivar/elnino

[Sally Furniss]

Re: La Nina Weather Pattern to Continue Through the Summer 2009

Once an El Ni?o or La Ni?a event gets underway, its development can be tracked from the Tropical Atmosphere Ocean (TAO) array of buoys in the tropical Pacific, and using sea surface temperature and altitude data sensed remotely by satellites. These measurements assist with the forecasting of such events.

http://www.niwa.co.nz/our-science/climate/information-and-resources/clivar/elnino