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- Ελληνικά
Although climate change is now the most obvious excuse for the extreme phenomena we have seen more and more often in recent years, this year's high temperatures and heavy rainfall expected in many parts of the world are the result of the El Niño phenomenon. A phenomenon that is an important factor in the distribution of planetary temperature and changes in water temperature, and significantly affects the weather and climate patterns of many regions worldwide.
The El Niño phenomenon is a natural periodic climate disturbance, which occurs every 2 to 7 years, lasts from 9 to 12 months and is associated with an increase in surface temperatures in the central and eastern part of the Pacific Ocean, i.e. in its equatorial zone.
Under El Niño conditions, winds in the tropical regions of the Pacific Ocean appear weakened, allowing warm surface waters from the Western Pacific Ocean to shift further east, as shown in Figure 1 below.
Now in the opposite of El Niño, i.e. La Niña, the surface of the Pacific Ocean, in its tropical regions, cools more than normal, thus affecting the weather and climate patterns of many regions globally.
The precipitation zone shows a similar shift to that of the warm waters. Thus, South America is receiving increased rainfall, experiencing quite frequent flooding, while regions such as India, Indonesia and Australia are experiencing severe drought. In North America the effects of El Niño are largely indirect, with warmer than normal winters in the northwestern U.S. and Canada and fairly dry winters in the western U.S. In parts of East Africa, continuous rainfall from March to May is at a maximum, while indirect effects of El Niño are found in many other parts of the world.
The term El Niño, which means "the little boy" in Spanish, essentially refers to the Unborn Child as the phenomenon usually occurs at its peak intensity during the Christmas season on the western coast of South America, near the coasts of Peru and Ecuador.
It is important to note that the very warm waters in the area where the phenomenon occurs result in an increase in the temperature of the overlying atmospheric air in the region, which results in an increase in the global average temperature.
According to the World Meteorological Organization (WMO), El Niño conditions developed again in the tropical Pacific Ocean by early 2023, after 7 years, setting the stage for a possible rise in global temperatures as well as a general disruption of weather and climate patterns. According to the latest IMO update, there is a 90% chance that El Niño will continue into the second half of 2023, when it is expected to be at least moderately intense. This means that the occurrence of El Niño is very likely to significantly increase the likelihood that some temperature records will be exceeded and that more extreme heat events (heat waves) will be triggered in several parts of the world. Also, a report by the IMO published last May predicted that there will be a 98% chance that at least one of the next 5 years will be the warmest year on record, as well as the 5-year period as a whole, surpassing the record set in 2016 when there was an extremely strong El Niño.
As oceanic regions are expected to experience higher than average sea surface temperatures, this is expected to contribute to the widespread forecast for above-normal temperatures in land areas as well. Without any exception, generally positive temperature anomalies are expected for the July, August and September quarter in all land areas in both the northern and southern hemispheres. And the rainfall projections for the next 3 months are similar to some of the normal effects of El Niño rainfall, such as increased rainfall in parts of South America, southern parts of the US, eastern part of Africa as well as central Asia or may cause severe droughts in Australia, Indonesia as well as Central America and some other regions.
Regarding the Eastern Mediterranean region and Cyprus, during an El Niño year cyclogenesis in the Mediterranean basin is favoured, resulting in a wetter climate with increased rainfall in the Eastern Mediterranean. However, we should note that the effects of El Niño in this region can be complex and variable and the exact nature of the changes depends on many factors.
More information, regarding El Niño and La Niña phenomena, can be found in the link below: https:/mailchi.mp/wmo.int/world-meteorological-organization-declares-onset-of-el-nio-conditions?e=5d124da96e
(MX)
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