Scientists anticipate the phases of the El Niño-Southern Oscillation by identifying differences between sea-surface temperatures in the equatorial Pacific and those elsewhere in the tropics.

Because the intensity of the phases in the cycle is sensitive to small variations in atmospheric and ocean conditions and depends on complex interactions between these two systems, no two El Niño or La Niña events are identical. This contributes to the variability in the length of each phase, which is why an ENSO can last as little as two years or as long as seven.

An analysis of El Niño and La Niña patterns from 1901 to 2020 suggests that anthropogenic warming—global warming caused by humans—has at least partly contributed to increased ENSO variability in recent decades. While ENSO increases the likelihood of droughts and flooding across different regions, researchers say these severe weather events are made more extreme by greenhouse gas emissions.

Second only to the seasons, ENSO is the most significant source of variability in global climate, shifting rainfall and temperature patterns, particularly in Africa, Latin America, and South and Southeast Asia. The incidence of vector-borne diseases like malaria, respiratory diseases related to wildfire smoke, food insecurity, and drought-related health and nutritional impacts has been observed to be affected by ENSO.

El Niño causes warm water to move east, disrupting ocean life and bringing wetter conditions to the southern US and drier ones to the North. La Niña strengthens the usual wind patterns, triggering cooler northern winters and more storms in the Pacific Northwest.

During La Niña, trade winds reinforce the flow of warm ocean water from the eastern to the western Pacific, allowing colder subsurface water in the eastern Pacific to rise to the surface. These changes reinforce overhead air movements by altering the air temperature near the ocean surface. During El Niño, these trade winds weaken or reverse, preventing upwelling by shifting warm water back to the eastern Pacific and displacing atmospheric circulation patterns.

Jet streams are predominantly west-to-east air currents in the atmosphere that mark the boundary between cold polar air and warm tropical air, where cells of atmospheric circulation meet. By disrupting the location of these circulations on two- to seven-year cycles, ENSO alters the probability of droughts, floods, and above- or below-average temperatures across the US.

Although the El Niño-Southern Oscillation is among the most impactful, the North Atlantic Oscillation strongly influences weather patterns in the Northeast US by periodically changing atmospheric pressure over the Atlantic. The North Pacific Oscillation fluctuates atmospheric pressure and sea-surface temperatures that affect winter temperatures over much of the US.

A comprehensive deep dive tracking components of the climate system over time, such as temperature, sea level, sea ice amounts, ocean heat, greenhouse gases, and more (w/charts and graphs).

The Geomagnetic Storm scale indicates the expected severity of the deformation of Earth's magnetic field based on the amount of energy injected by the solar wind. Solar activity is monitored using various satellites to forecast these storms, which can also be used to anticipate damage and disruption to power systems, radio communications, and satellite navigation.

How much does the temperature of the sea change in a given year? This visualization helps illustrate the changes by showing sea surface temperature data from January 2016 through March 2020. Sea surface temperature, which refers to water temperature at the sea's surface, plays a significant role in climate and weather.

Essential climate variables include physical, chemical, and biological variables that meaningfully contribute to Earth's climate and how it changes with time. Many of these variables influence one another through feedback mechanisms across Earth's atmosphere, hydrosphere, cryosphere, biosphere, and geosphere.

Volcanic activity on the seafloor produces high ratios of helium-3 to helium-4, which can be tracked in ocean samples more easily than other elements because helium is nonreactive. Water from deep ocean currents can also be distinguished from air-exposed surface water sources by comparing these ratios, since atmospheric helium ratios are much lower.

The rise in sea levels is primarily due to melting ice in Greenland and Antarctica, and predicted levels have been confirmed accurate by satellite observations. Ocean currents influence regional variations in sea level rise, which are expected to accelerate.

Emissions of this molecule increased 40% from 1980 to 2020, with atmospheric concentrations reaching levels higher than at any other time in the last 800,000 years, based on ice core records. Its warming potential is 273 times that of carbon dioxide over 100 years and remains in the atmosphere for more than a century, on average.

As more parts of the world are facing extreme weather, from high temperatures to increased natural disasters, there is much debate about what can be done. MIT News explores and explains the 1.5-degree benchmark for limiting the effects of climate change. Read to understand where the planet stands in relation to this threshold and what can be done at the global, regional, and personal levels to “keep 1.5 alive.”

How will rising seas affect you? Launch NOAA's sea level rise viewer and zoom in on impacts to different parts of the United States, or type in your city or address to learn more.

These cycles include changes in Earth's orbit shape, tilt, and wobble, all of which alter how much solar energy different parts of Earth receive over time. Due to orbital eccentricity, summers in the Northern Hemisphere last about 4.5 days longer than winters.

While some volcanoes erupt with predictable signs, such as surface deformation from the build-up of underground magma pressure, others release magma at inconsistent rates. Extensive monitoring is needed to identify less clear patterns and indicators of future eruptions.

Hindcasting tests model forecasts against observational data to determine their accuracy. In this interactive, you can learn about the differences between eight climate models and evaluate them against available climate data.

An incredible interactive project showing how global warming is projected to affect the world, from temperatures to rainfall, droughts and flooding, and more.

Between 750 and 1350 CE, some regions experienced temperatures that rivaled or exceeded late-20th-century averages, likely due to shifts in El Niño–La Niña cycles. The warmer, wetter climate in Europe and northeast North America boosted agriculture, while causing droughts elsewhere.

The Earth orbits the Sun in an elliptical shape, and winter in the Northern Hemisphere occurs when the Earth reaches the point in its orbit closest to the Sun, known as perihelion. The lower temperatures result from the hemisphere tilting away from the Sun.

Scientists use satellites, balloons, ocean buoys, and land-based instruments to track climate variables like temperature, precipitation, and wind. These tools gather data from deep ocean waters to the upper atmosphere.

The Global Monitoring Laboratory conducts research on greenhouse gas and carbon cycle feedbacks, changes in clouds, aerosols, and surface radiation, and recovery of stratospheric ozone.

By studying extreme environments in Earth's hadal zone—the deepest part of the ocean —NASA tests technologies, probes life under crushing pressure, and gathers clues about potential oceans and possible life on worlds like Europa and Enceladus.

The Atlantic Meridional Overturning Circulation plays a critical role in regulating earth's climate, but is threatened by climate change. Explore the effects of temperature, density, and salinity on ocean currents in this 13-minute PBS video.

The En-ROADS tool lets you role-play as a global decision maker to explore the long-term effects of various policy ideas on climate. More than 341,000 people worldwide, including over 130 members of Congress, have used the simulation.

More than 4,000 robotic floats with biogeochemical data sensors, including oxygen, pH, nitrate, suspended particles, chlorophyll, temperature, and conductivity, have been deployed as part of the Global Ocean Biogeochemical Array. They have identified changes to ecosystem structure affecting the ocean's ability to transport carbon from surface waters into the deep.

A fun interactive on how old ships’ logs are giving scientists new insights into the past and future of the Earth’s changing climate (w/maps and pictures).

Seen via ultraviolet radiation scattered by neutral hydrogen in the region, observations by the ESA/NASA Solar and Heliospheric Observatory indicate that the geocorona extends roughly 50 times Earth's diameter above its surface. At this distance, the geocorona extends beyond the Moon's orbit.