January 20, 2014

The Arctic Oscillation describes simultaneous, geographically “choreographed” shifts in multiple features of the polar vortex: air pressure, temperature, and the location and strength of the jet stream. They all follow the hemisphere-wide oscillation of atmospheric mass back and forth between the Arctic and the middle latitudes, sort of like water sloshing in a bowl.

January 10, 2014

A few days of unusually cold weather in the U.S. and Canada aren't a sign that a century-or-more trend of rising global surface temperatures has reversed itself. In fact, the cold wasn't even all that widespread for the Northern Hemisphere.

January 8, 2014

Meteorologists have known for years that the pattern of the polar vortex determines how much cold air escapes from the Arctic and makes its way to the U.S. during the winter. Climate scientists are wondering if a warmer Arctic could explain its odd behavior in recent years.

November 6, 2013

October in Alaska this year was more like September, with warmth and rain in place of autumn chill and snow. Wind anomalies related to unusual pressure patterns conspired to bring a steady stream of warm, wet air from southerly latitudes into Alaska.

October 30, 2013

For much of Alaska, lack of snow, soaking rains, and record-warmth have made October feel more like September.

April 18, 2013

Much colder-than-average temperature during March and a strongly negative Arctic Oscillation Index reminded people in the United States how important this index is to our own climate conditions.

February 5, 2013

As the whole ocean gets warmer, NOAA scientists must redefine what they consider “average” temperature in the central tropical Pacific, where they keep watch for El Niño and La Niña.

December 17, 2012

Deke Arndt, Chief of the Climate Monitoring Branch, at the National Climatic Data Center talks about the influence of La Niña on the 2011 global average temperature. 

September 13, 2012

 

In a place routinely afflicted by drought, water managers in Tampa Bay use climate forecasts to ensure a water supply to people’s taps without sucking the region’s rivers, wetlands, and groundwater dry. The limits of their innovation might be tested in a future which could pose even more challenges to ensuring the oasis remains green.

 

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