Saturday 29 April 2017

2017 to be one of the hottest years: study

2017 to be one of the hottest years: study

2017 will be among the hottest years on record, say scientists who have developed a new method for predicting(भविष्यवाणी) global mean temperature. Researchers at Yale University in the US found that weak El Nino activity from 1998 until 2013, rather than a pause in long-term global warming, was the root cause for slower rates of increased surface temperature. They also found that volcanic activity played only a minor role. 

"From a practical perspective, our method, when combined with El Nino prediction, allows us to predict next-year global mean temperature," said Alexey Fedorov, professor at Yale University. "

Accordingly, 2017 will remain among the hottest years of the observational record, perhaps just a notch colder than 2016 or 2015," Fedorov said. El Nino events contribute to year-to-year variations in global mean temperature by modulating the heat that is released from tropical oceans into the atmosphere, researchers said. 

El Nino warms the atmosphere, while the cold phase of the phenomenon, La Nina, cools the atmosphere. The new model closely mirrors global mean surface temperature (GMST) changes since 1880, including the so-called global warming hiatus and the more recent temperature rise. 

"Our main conclusion is that global warming never went away, as one might imply from the term 'global warming hiatus,'" Fedorov said. "The warming can be masked by inter-annual and decadal natural climate variability, but then it comes back with a vengeance(प्रतिशोध)," said Fedorov. 

Multiple strong El Nino events occurred in the 1980s and 1990s. This was followed by much weaker El Nino activity, which lasted until 2014. "The recent rapid rise in global temperature mainly resulted from the prolonged 2014-2016 El Nino conditions in the tropics that reached an extreme magnitude in the winter of 2015," said Shineng Hu, first author of the study published in the journal Geophysical Research Letters. 

"The corresponding (संबंधित) heat release into the atmosphere, together with the ongoing background global warming trend, made 2014, 2015, and 2016 the three consecutive warmest years of the instrumental record so far," Hu said.





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Definitions of (vengeance प्रतिशोध)

noun
punishment inflicted or retribution exacted(उचित) for an injury or wrong.
So in the end it sort of has a happy ending, in that you get to see Grace exact vengeance .
synonyms: revenge, retribution, retaliation, payback, requital, reprisal, satisfaction, an eye for an eye (and a tooth for a tooth).


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El Niño and La Niña 

El Niño and La Niña are opposite phases of what is known as the El Niño-Southern Oscillation(कंपन) (ENSO) cycle. The ENSO cycle is a scientific term that describes the fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific(पूर्व-मध्य इक्वेटोरियल प्रशांत) (approximately between the International Date Line and 120 degrees West). 

La Niña is sometimes referred to as the cold phase of ENSO and El Niño as the warm phase of ENSO. These deviations(विचलन) from normal surface temperatures can have large-scale impacts not only on ocean processes, but also on global weather and climate.

El Niño and La Niña episodes typically last nine to 12 months, but some prolonged events may last for years. While their frequency can be quite irregular, El Niño and La Niña events occur on average every two to seven years. Typically, El Niño occurs more frequently than La Niña. 

El Niño (warm phase)

El Niño means The Little Boy, or Christ Child in Spanish. El Niño was originally recognized by fishermen off the coast of South America in the 1600s, with the appearance of unusually warm water in the Pacific Ocean. The name was chosen based on the time of year (around December) during which these warm waters events tended(देखते हुए) to occur.

The term El Niño refers to the large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific.

Typical El Niño effects are likely to develop over North America during the upcoming winter season. Those include warmer-than-average temperatures over western and central Canada, and over the western and northern United States. Wetter-than-average conditions are likely over portions of the U.S. Gulf Coast and Florida, while drier-than-average conditions can be expected in the Ohio Valley and the Pacific Northwest. The presence of El Niño can significantly influence weather patterns, ocean conditions, and marine fisheries across large portions of the globe for an extended period of time.


La Niña (cold phase)

La Niña means The Little Girl in Spanish. La Niña is also sometimes called El Viejo, anti-El Niño, or simply "a cold event."

La Niña episodes represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific. Global climate La Niña impacts tend to be opposite those of El Niño impacts. In the tropics, ocean temperature variations in La Niña also tend to be opposite those of El Niño.

During a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest.

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