Much of the country and for that matter the Northern Hemisphere has been locked in an icy weather pattern that sent records tumbling and even forced Florida produce growers to seal oranges and strawberries in ice to protect them from frigid temperatures.
Some scientists are saying this is yet another sign of the extreme temperature fluctuations that climate change is bringing. Others are quick to dismiss this cold stretch as evidence of anything but a cold winter.
But there is a climate force at work. Called the Arctic Oscillation, scientists noticed that the air pressure that usually remains high at the top of the world weakened and became very low in December. That allowed the coldest Arctic air to flow south and cover large swaths of the Northern Hemisphere.
