Natural Climate Patterns

We're nine laps into the race to set a new global annual temperature record. NOAA climate scientist Deke Arndt talks about how this year's race might end--and why yearly rankings tell us less about the big picture of climate change than we might think.

Saturday, August 1, 2009

  • The Southern Oscillation Index tracks differences in air pressure between the eastern and western sides of the tropical Pacific.

  • 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.

  • Over the span of days or weeks, the strength of surface air pressure over the North Atlantic seesaws between Iceland and the Azores Islands. The shifting pressure reflects changes in atmospheric circulation that have a big impact on mid-latitude weather in the U.S. and Europe. 

  • El Niño and La Niña conditions occur when abnormally warm or cool waters accumulate in tropical latitudes of the central and eastern Pacific Ocean. The Oceanic Nino Index is the tool NOAA scienitsts use to watch for these temperature changes.