Atmospheric Teleconnections

by

Gregory Goodrich

• LAST REVIEWED: 24 April 2023
• LAST MODIFIED: 24 April 2023
• DOI: 10.1093/obo/9780199874002-0147

Introduction

Climate teleconnections are commonly defined as low-frequency variability in the atmosphere and oceans, while weather is defined as random high-frequency variability in the atmosphere. A secondary definition of teleconnections is that of significant correlations of climatological variables at widely separated points on the earth, showing evidence of preferred trough/ridge positions. These preferred modes of variability can be measured through the use of indices to quantify flow patterns associated with the teleconnection. The indices can then be correlated with climate variables across the globe that display significant relationships. Teleconnections can have periods ranging from several weeks to several decades and can affect temperature, precipitation, storm tracks, severe weather, and drought. The strength and coherence of a teleconnection’s signal often changes over time, and evidence suggests that the phase of the multidecadal ocean oscillations in the Atlantic and Pacific are often the cause. Extreme weather is often influenced by teleconnection patterns that cause persistent weather in various locations. Teleconnections are often a useful tool for seasonal forecasters and are commonly used in predicting commodity and energy trading markets. While many teleconnections were originally empirically derived, there has been progress in understanding the physical mechanisms behind many of them, which has helped to improve their predictability. There is much uncertainty regarding how climate change will affect many teleconnections, and this is an area of active research. The objective of this article is to introduce atmospheric and oceanic teleconnections that commonly affect weather patterns in the United States and around the globe. The article will introduce the history of how teleconnections were discovered and the statistics of how the index that determines the phase of the teleconnection was calculated. Several oceanic and atmospheric teleconnections will be discussed along with their known impacts on weather and climate.

Reference Resources

There are a growing number of online resources that contain information related to climate teleconnections. Most of the resources are housed within governmental agencies although a few are housed on university campuses. The Climate Prediction Center (CPC) and Physical Sciences Laboratory (PSL), both branches within the National Oceanic and Atmospheric Administration (NOAA), have several websites dedicated to climate teleconnections. The CPC websites include information about all Northern Hemisphere atmospheric teleconnections in addition to monthly determinations of the phases of El Niño–Southern Oscillation (ENSO) (see Northern Hemisphere Teleconnections Patterns and El Niño and La Niña Episodes by Season). The largest number of teleconnection time series can be found at PSL, which also provides a way to calculate correlations with US climate division data (see Teleconnection Correlations, and Teleconnections Time Series). The National Climatic Data Center (NCDC), also a branch of NOAA; the Joint Institute for the Study of Atmosphere and Ocean (JISAO); and the International Research Institute (IRI) also provide useful teleconnection datasets.

• Climate Prediction Center. El Niño and La Niña Episodes by Season.

  Historical table of months of El Niño, La Niña, and neutral ENSO conditions dating back to 1950. The data are useful for analyses of ENSO correlations in different seasons.

• Climate Prediction Center. Northern Hemisphere Teleconnections Patterns.

  This website provides historical time series, pattern calculations, and a brief history of many of the atmospheric teleconnections discussed in this article. Correlation maps of temperature and precipitation for the positive phase of each teleconnection are also available.

• International Research Institute. Teleconnections Data Library.

  The IRI data library has a large number of teleconnection time series, with an especially large variety of time series related to ENSO.

• Joint Institute for the Study of Atmosphere and Ocean. Pacific Decadal Oscillation Time Series.

  The Pacific Decadal Oscillation (PDO) was developed at JISAO, and this website provides the entire historical time series of the PDO in addition to a description of the index.

• National Climatic Data Center. Teleconnections.

  Provides historical information and time series of many of the leading modes of Northern Hemisphere variability.

• Physical Sciences Laboratory. Teleconnection Correlations.

  This website allows the user to develop maps of correlations between US climate division data (temperature, precipitation, and drought) and many of the teleconnections discussed in this paper.

• Physical Sciences Laboratory. Teleconnections Time Series.

  A comprehensive list of time series of many of the oceanic and atmospheric teleconnections found in this article. Multiple versions of some teleconnections are available as are some lesser-known teleconnections.