New coral data traces 7,000 years of El Niño history

Posted on January 4, 2013 by Bob Berwyn

20th century oscillations show intensification that may be linked with global warming

El Nino graphic

A NOAA graphic showing early January 2012 ocean surface temperature anomalies.

By Summit Voice

SUMMIT COUNTY — Atmospheric scientists say they’ve used coral records to trace the history of El Niño cycles going back about 7.000 years, showing that 20th century oscillations  are much stronger than those captured in the fossil record.

But the study also showed large natural variations in past ENSO strength, making it difficult to attribute the 20th century intensification of ENSO to rising carbon dioxide levels. Such large natural fluctuations in ENSO activity are also apparent in multi-century climate model simulations, but the 20th century intensification stands out as statistically significant and could be linked with global warming.

The new information will help assess the accuracy of climate model projections for 21st century climate change in the tropical Pacific. (more…)

Filed under: climate and weather, El Niño, Environment | Tagged: , , , , , , , | Leave a Comment »

Global warming: Arctic ice loss has profound impact on weather patterns over North America, Asia and Europe

Posted on February 28, 2012 by Bob Berwyn

This map shows the percent change in winter blockings relative to the long-term average. Blocking patterns favor more frequent movement of cold air masses to middle and lower latitudes, leading to increased heavy snowfall in Europe and the Northeast and Midwest regions of the United States. Credit: Georgia Tech/Jiping Liu

Global circulation patterns shift, bringing more frequent blocking patterns and polar outbreaks

By Summit Voice

SUMMIT COUNTY — Evidence is growing that the loss of Arctic sea ice is having a profound effect on seasonal weather patterns over North America, Europe and Asia.

In addition to previous research from the Rutgers University Institute of Marine and Coastal Sciences, a new study led by the Georgia Institute of Technology again shows the  relationship between melting ice in the Arctic regions and widespread cold outbreaks in the Northern Hemisphere.

The study’s findings could be used to improve seasonal forecasting of snow and temperature anomalies across northern continents.

Since the level of Arctic sea ice set a new record low in 2007, significantly above-normal winter snow cover has been seen in large parts of the northern United States, northwestern and central Europe, and northern and central China. During the winters of 2009-2010 and 2010-2011, the Northern Hemisphere measured its second and third largest snow cover levels on record. (more…)

Filed under: climate and weather, Environment, global warming, seasons, Snow and weather, Summit County news | Tagged: , , , , , | 1 Comment »

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