Question

What is a circulation pattern in which the atmospheric pressur over the polar regions varies in opposition with that over middle lattitudes on time scales ranging from weeks to decades, the negative or cold phase of this circulation pattern is typically assocated with cold and snowy weather in the Eastern US?

Answer 1

The Arctic Oscillation (AO) is the circulation pattern affecting weather by varying atmospheric pressure between polar and mid-latitude regions, influencing cold and snowy conditions in the Eastern US.

Step-by-step explanation:

The circulation pattern described in the question is known as the Arctic Oscillation (AO) or the Northern Annular Mode. This climate pattern involves atmospheric pressure anomalies at polar and middle latitudes which lead to fluctuations in cold and warm air distribution. When the AO is in its negative phase, it typically results in cold and snowy weather in the Eastern United States due to the southward movement of polar air. Meteorologists use weather maps displaying regions of high and low pressure, along with isobars, to predict such weather conditions.