woensdag 23 december 2015

Climate Change

YULETIDE HEATWAVE

Scores of eastern U.S. cities to shatter Christmas Eve warm weather records




The warm air surging up the East Coast on Christmas Eve will prove nothing short of historic. Dozens of records will fall, some by very large margins.
Temperatures at or above 70 degrees will span from Florida all the way into southern New England covering some 1,200 miles and 20 percent of the Lower 48.
In many places in the East, temperatures will run some 30-40 degrees above normal.
The warmth in a few locations will be so anomalous that low temperatures will challenge existing records highs.
The map below shows all of the locations where records highs are in jeopardy, from Florida to Maine.
Here are a few highlights:

* The temperature in Buffalo is forecast to be near 60 degrees at midnight, the start of Christmas Eve, breaking its record high for the date in the middle of the night.

https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/12/23/scores-of-eastern-u-s-cities-to-shatter-christmas-eve-warm-weather-records/


Here's Yet Another Alarming Effect Of Melting Arctic Sea Ice

Scientists reveal why the influence melting sea ice has on precipitation could be bad.

12/23/2015 10:53 am ET


JZ_photo via Getty Images


Less Arctic sea ice may mean more rainfall, according to new research.
Scientists have long known that the melting sea ice in the Arctic leads to more heat being absorbed by our planet, which can disturb the ecosystem.
However, according to a new study, published Tuesday in the Proceedings of the National Academy of Sciences,  there is yet another effect that vanishing ice has on our planet: The disappearing sea ice is linked to more precipitation in the Arctic.
This could impact the environment in a way that's comparable to doubling the amount of carbon dioxide in the global atmosphere, Ben Kopec, a Ph.D candidate in Dartmouth College's Department of Earth Sciences and lead author of the study, told The Huffington Post.
"As sea ice is reduced, ocean water is exposed to the atmosphere, leading to increased evaporation, and ultimately more precipitation," Kopec said. "The impacts of changing precipitation on the global climate system are significant."
The researchers collected measurements of the precipitation at six sites across the Arctic from 1990 to 2012. They took a close look at the chemical makeup of the precipitation samples to establish how sensitive the precipitation was to ice melt, the Christian Science Monitor reported.
Then, the researchers empirically compared that data to how the sea ice changed during the same time period.
The researchers found that as the sea ice shrunk 38,610 square miles, the percentage of moisture in the atmosphere increased by 18.2 percent in the Canadian Arctic and 10.8 percent in the Greenland Sea regions.
The findings not only confirm a link between ice melt and precipitation, but they also correspond with other findings that show that the environment may be adapting to warming temperatures, according to the researchers.
If the increased moisture in the atmosphere leads to snow, Kopec said, then the snowfall may have the potential to reflect more sunlight and actually reduce the amount of heat absorbed. But problems may arise if the moisture leads to rainfall. Not only would rain melt even more snow and ice in the Arctic but it could also stall the onset of autumn snow, which would lead to additional warming.
"Sea ice is declining at an alarming rate, so it is important to understand the consequences of the climate feedbacks caused by these changes," Kopec said in a statement. "We show that the loss of sea ice will likely increase precipitation, which will impact communities and ecosystems around the Arctic. The change of precipitation, depending on the seasonal distribution, may impact the energy balance on the same order of magnitude as the feedbacks associated with doubling carbon dioxide."
The new study supports the growing consensus that melting sea ice, caused by climate change, results in increased Arctic precipitation, Julienne Stroeve, senior research scientist at the National Snow and Ice Data Center at the University of Colorado in Boulder, told the Associated Press.
"At least statistically there's a correlation between less sea ice and more precipitation in certain parts of the Arctic," she said.

http://www.huffingtonpost.com/entry/melting-arctic-ice-precipitation_56796ffde4b014efe0d6c7fa


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