The Pacific-North American teleconnection pattern influences regional weather by affecting the strength and location of the East Asian jet stream, and subsequently, the weather it delivers to North America.

The total amount of water on Earth isn’t increasing, but the volume of liquid that fills the ocean is growing as ice and snow on land melt. The water is also getting warmer, which makes it expand. 

Minimum sea ice extent observed by satellites each September has decreased by 13.7 percent per decade since the late 1970s. The seven lowest extents all occurred since 2007.

(Updated June 2, 2014)

The Arctic Oscillation (AO) refers to an atmospheric circulation pattern over the mid-to-high latitudes of the Northern Hemisphere. The most obvious reflection of the phase of this oscillation is the north-to-south location of the storm-steering, mid-latitude jet stream.