0.1 Climate Teleconnection
Teleconnections are significant relationships or links between weather phenomena at widely separated locations on earth, which typically entail climate patters that span thousands of miles. Many teleconnection patterns behave like a seesaw, with atmospheric mass/pressure shifting back and forth between two distant locations—an increase in, say, atmospheric pressure in one location results in a decrease in pressure somewhere far, far away.
Figure 1: Late winter temperatures compared to the 1981-2010 average when the North Atlantic Oscillation (NAO) was strongly negative (top, Jan-March 2010) and when it was strongly positive (bottom, January-March 1990). Winters are often cooler than average across the mid-latitudes when the NAO is negative, and warmer than average when it is positive. NOAA Climate.gov image, based on data from the Physical Sciences Lab.
One of the most famous drivers of teleconnection patterns is our good buddy ENSO (perhaps we are a little biased) a.k.a the El Niño/Southern Oscillation. The “Southern Oscillation” refers to changes in sea-level pressures that are centered over the eastern tropical Pacific and over Indonesia (learn more here and here). Followed closely in notoriety is the Pacific-North American pattern, an oscillatory pressure pattern over the Pacific Ocean and North America, which influences North American and European temperature and precipitation.