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 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.
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.