Strong polar vortex winds normally trap cold air in the Arctic and circle the North Pole from west to east. This pattern broke down this month, allowing cold Arctic air to spill over the central United States and create record cold temperatures for the eastern half of the United States.

This isn’t the first time that the polar vortex has been weak. During late autumn and early winter in 2005, 2008, 2009 and 2010, weak polar vortex winds were associated with an increase of cold air moving south from the Arctic. During this event in 2009, North America was 3 to 18 °F cooler than normal monthly averages, and the Arctic region was more than 7 °F warmer than average.

Scientists think there may be a connection between the intense, short-term cold weather patterns that hit many parts of the country and the warming Arctic. Understanding the link between more severe weather in the mid-latitudes and less sea ice and snow cover in the Arctic is an active area of research.

More work needs to be done to understand these global, atmospheric connections. But we already know that the Arctic is changing dramatically. The most visible indication of this change is the long-term decline of Arctic summer sea ice from climate change. The seven lowest levels of Arctic summer sea ice on satellite record have occurred in the last seven years, from 2007 to 2013. These changes in Arctic climate—together with the threats posed by increasing industrial activity in the region—could have dire consequences not only for the Arctic and its wildlife, but for our entire planet.