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

Temperatures measured on land and at sea for more than a century show that Earth's globally averaged surface temperature is experiencing a long-term warming trend.

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. 

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. 

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.

Climate Change 2014: Impacts, Adaptation, and Vulnerability

On March 31 in Yokohama, Japan, the Intergovernmental Panel on Climate Change approved and released Working Group II's Summary for Policymakers and the underlying scientific and technical assessment.

Climate Change and Infrastructure, Urban Systems, and Vulnerabilities

This Technical Input to the U.S. National Climate Assessment examines vulnerabilities of infrastructures and urban systems to extreme weather and other events associated with climate change.