A rectangular box-shaped spacecraft with long arms extending from either side. Above the arms are wing-like solar panels extending in the opposite direction. The curvature of Earth and wispy clouds are depicted just below the spacecraft.

Explore how and why the SWOT mission will take stock of Earth's water budget, what it could mean for assessing climate change, and how to bring it all to students.

Update: Dec. 15, 2022 – NASA, the French space agency, and SpaceX are now targeting 3:46 a.m. PST (6:46 a.m. EST) on Friday, Dec.16, for the launch of the Surface Water and Ocean Topography (SWOT) satellite. Visit NASA's SWOT launch blog for the latest updates.


NASA is launching an Earth-orbiting mission that will map the planet’s surface water resources better than ever before. Scheduled to launch on Dec. 16 from Vandenberg Space Force Base in California, the Surface Water and Ocean Topography, or SWOT mission is the latest international collaboration designed to monitor and report on our home planet. By providing us with a highly detailed 3D view of rivers, lakes, and oceans, SWOT promises to improve our understanding of Earth’s water cycle and the role oceans play in climate change, as well as help us better respond to drought and flooding.

Read on to find out why we're hoping to learn more about Earth's surface water, get to know the science behind SWOT's unique design, and follow along with STEM teaching and learning resources.

Why It's Important

Observing Earth from space provides scientists with a global view that is important for understanding the whole climate system. In the case of SWOT, we will be able to monitor Earth’s surface water with unprecedented detail and accuracy. SWOT will provide scientists with measurements of water volume change and movement that will inform our understanding of fresh water availability, flood hazards, and the mechanisms of climate change.

Scientists and engineers provide an overview of the SWOT mission. Credit: NASA/JPL-Caltech | Watch on YouTube

Water Flow

Scientists use a variety of methods to track Earth’s water. These include stream and lake gauges and even measurements from space such as sea surface altimetry and gravitational measurements of aquifer volumes. Monitoring of river flow and lake volume is important because it can tell us how much freshwater is readily available and at what locations. River flow monitoring can also help us make inferences about the downstream environmental impact. But monitoring Earth’s surface water in great detail with enough frequency to track water movement has proven challenging. Until now, most monitoring of river flow and lake levels has relied on water-flow and water-level gauges placed across Earth, which requires that they be accessible and maintained. Not all streams and lakes have gauges and previous space-based altimetry and gravitational measurements, though useful for large bodies of water, have not been able to adequately track the constant movement of water through smaller rivers or lakes.

Here's why understanding Earth’s "water budget" is an important part of understanding our planet and planning for future water needs.

SWOT will be able to capture these measurements across the globe in 3D every 21 days. The mission will monitor how much water is flowing through hundreds of thousands of rivers wider than 330 feet (100 meters) and keep a close watch on the levels of more than a million lakes larger than 15 acres (6 hectares). Data from the mission will be used to create detailed maps of rivers, lakes, and reservoirs that will enable accurate monitoring to provide a view of freshwater resources that is not reliant on physical access. Meanwhile, SWOT’s volumetric measurements of rivers, lakes, and reservoirs will help hydrologists better track drought and flooding impacts in near-real-time.

Coastal Sea Level Rise

SWOT will measure our oceans with unprecedented accuracy, revealing details of ocean features as small as 9 miles (15 kilometers) across. SWOT will also monitor sea levels and tides. Though we have excellent global sea level data, we do not have detailed sea level measurements near coastlines. Coastal sea levels vary across the globe as a result of ocean currents, weather patterns, land changes, and other factors. Sea levels are rising faster than ever, and higher sea levels also mean that hurricane storm surges will reach farther inland than ever before, causing substantially more damage than the same category of hurricanes in the past. SWOT will be able to monitor coastal sea level variations and fill gaps in the observations we currently have from other sources.

What is sea level rise and what does it mean for our planet? | › View Transcript

Ocean Heat Sinks

Further contributing to our understanding of the role Earth’s oceans play in climate change, SWOT will explore how the ocean absorbs atmospheric heat and carbon, moderating global temperatures and climate change. Scientists understand ocean circulation on a large scale and know that ocean currents are driven by temperature and salinity differences. However, scientists do not currently have a good understanding of fine-scale ocean currents, where most of the ocean's motion-related energy is stored and lost. Circulation at these fine scales is thought to be responsible for transporting half of the heat and carbon from the upper ocean to deeper layers. Such downward ocean currents have helped to mitigate the decades-long rise in global air temperatures by absorbing and storing heat and carbon away from the atmosphere. Knowing more about this process is critical for understanding the mechanisms of global climate change.

JPL scientist Josh Willis uses a water balloon to show how Earth's oceans are absorbing most of the heat being trapped on our warming world. | › Related lesson

These fine-scale ocean currents also transport nutrients to marine life and circulate pollutants such as crude oil and debris. Understanding nutrient transport helps oceanographers assess ocean health and the productivity of fisheries. And tracking pollutants aids in natural hazard assessment, prediction, and response.

How It Works

A joint effort between NASA and the French space agency – with contributions from the Canadian and UK space agencies – SWOT will continue NASA’s decades-long record of monitoring sea surface height across the globe. But this mission will add a level of detail never before achieved.

SWOT will measure more than 90% of Earth’s surface water, scanning the planet between 78°N latitude and 78°S latitude within 1 centimeter of accuracy and retracing the same path every 21 days. Achieving this level of accuracy from a spacecraft height of 554 miles (891 kilometers) requires that the boom using radar to measure water elevation remain stable within 2 microns – or about 3% of the thickness of a human hair.

This visualization shows ocean surface currents around the world during the period from June 2005 through December 2007. With its new, high resolution wide-swath measurements, SWOT will be able to observe eddies and current features at greater resolution than previously possible. Credit: NASA Scientific Visualization Studio | Watch on YouTube

Prior to SWOT, spacecraft have used conventional nadir, or straight-down, altimetry to measure sea surface height. Conventional nadir altimetry sends a series of radar or laser pulses down to the surface and measures the time it takes for each signal to return to the spacecraft, thus revealing distances to surface features. To acquire more detailed information on surface water, SWOT will use an innovative instrument called the Ka-band Radar Interferometer, or KaRIn, to measure water height with exceptional accuracy. Ka-band is a portion of the microwave part of the electromagnetic spectrum. SWOT uses microwaves because they can penetrate clouds to return data about water surfaces.

A radar signal is sent straight down from the SWOT spacecraft as it flies over Earth. Beams are shown bouncing back to receivers on either side of the spacecraft. The section of Earth measured by the spacecraft is shown as two side-by-side tracks colored in as a heatmap. The camera zooms out to show these tracks criscrossing the planet and eventually covering a majority of the surface.

SWOT will track Earth's surface water in incredible detail using an innovative instrument called the Ka-band Radar Interferometer, or KaRIn. Image credit: NASA/JPL-Caltech | + Expand image

The KaRIn instrument uses the principles of synthetic aperture radar combined with interferometry to measure sea surface height. A radar signal is emitted from the end of the 10-meter-wide boom on the spacecraft. The reflected signal is then received by antennas on both ends of the boom, capturing data from two 30-mile (50-kilometer) wide swaths on either side of the spacecraft. The received signals will be slightly out of sync, or phase, from one another because they will travel different distances to return to the receivers on either end of the boom. Knowing the phase difference, the distance between the antennas, and the radar wavelength allows us to calculate the distance to the surface.

The first of three images shows two paths of different lengths extending diagonally from a point on Earth’s surface to receivers on either side of the SWOT spacecraft. A second image shows the paths as light waves that are slightly out of phase. The third image shows a line drawn directly from the rightmost receiver to the path leading to the leftmost receiver, such that the intersected paths from Earth are equal in length. The upper triangle formed by this intersection has a short leg, highlighted in yellow, that represents the remaining length of the leftmost path. The yellow short leg represents the range difference between the two paths from Earth.

Radar signals bounced off the water’s surface will be received by antennas on both ends of SWOT's 10-meter-wide boom. The received signals will be slightly out of phase because they will travel different distances as they return to the receivers. Scientists use this phase difference and the radar wavelength to calculate the distance to the surface. Image credit: NASA/JPL-Caltech | + Expand image

The observations acquired by the two antennas can be combined into what is known as an interferogram. An interferogram is a pattern of wave interference that can reveal more detail beyond the 1-centimeter resolution captured by the radar. To explain how it works, we'll recall a couple of concepts from high school physics. When out-of-phase waves from the two antennas are combined, constructive and destructive interference patterns result in some wave crests being higher and some wave troughs being lower than those of the original waves. The patterns that result from the combination of the waves reveal more detail with resolution better than the 1-centimeter wavelength of the original Ka-band radar waves because the interference occurs over a portion of a wavelength. An interferogram can be coupled with elevation data to reveal a 3D representation of the water’s surface.

A diagram illustrating the swaths of data that SWOT will collect, including labels for the following: 10 m baseline between SWOT's receivers; a distance of 891 km between the surface and Interferometer Antenna 1; Interferometer Left Swath resulting in ocean topography with an H-Pol swath of 10-60 km; Interferometer Right Swath resulting in surface water topography with a V-Pol of 10-60 km; a straight-down Nadir Altimeter path directly below the spacecraft in the gap between the swaths; a cross-track resolution from 70m to 10m.

The KaRIn instrument illuminates two parallel tracks of approximately 50 kilometres on either side of a nadir track from a traditional altimeter. The signals are received by two antennas 10 metres apart and are then processed to yield interferometry measurements. Image credit: NASA/JPL-Caltech | + Expand image

This highly accurate 3D view of Earth’s surface water is what makes SWOT so unique and will enable scientists to more closely monitor the dynamics of the water cycle. In addition to observing ocean currents and eddies that will inform our understanding of the ocean’s role in climate change, SWOT's use of interferometry will allow scientists to track volumetric changes in lakes and quantify river flooding, tasks that cannot yet be done on a wide scale in any other way.

A colorful swath of yellows, oranges, magentas, purples is overlaid horizontally on a satellite image of desert landscape with thin yellow and red lines cutting diagonally across the image. On the center-left of the image, the colors fan out like a rainbow sprinkler. On the left side of the swath are a cluster of yellow dots.

This interferogram was captured by the air-based UAVSAR instrument of the magnitude 7.2 Baja California earthquake of April 4, 2010. The interferogram is overlaid atop a Google Earth image of the region. Image credit: NASA/JPL/USGS/Google | › Learn more

Follow Along

SWOT is scheduled to launch no earlier than Dec. 16, 2022, on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California. Tune in to watch the launch on NASA TV.

After launch, the spacecraft will spend 6-months in a calibration and validation phase, during which it will make a full orbit of Earth every day at an altitude of 553 miles (857 kilometers). Upon completion of this phase, SWOT will increase its altitude to 554 miles (891 kilometers) and assume a 21-day repeat orbit for the remainder of its mission.

Visit the mission website to follow along as data are returned and explore the latest news, images, and updates as SWOT provides a new view on one of our planet's most important resources.

Teach It

The SWOT mission is the perfect opportunity to engage students in studying Earth’s water budget and water cycle. Explore these lessons and resources to get students excited about the STEM involved in studying Earth’s water and climate change from space.

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TAGS: K-12 Education, Teachers, Educators, Earth Science, Earth, Climate Change, Climate, Satellites, Teachable Moments, Climate TM

  • Ota Lutz
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A small piece of the ISS is visible in the top corner of this view looking down from space station over Earth. A large cloud of dust takes half the view over Earth's surface.

A data map overlaid on the globe shows thick swirls of dust traveling from West Africa, across the Atlantic Ocean and all the way to the Caribbean and Southern U.S.

Learn about the role that dust plays in Earth's climate, why scientists are interested in studying dust from space, and how to engage students in the science with STEM resources from JPL.


A NASA instrument launched to the International Space Station this summer will explore how dust impacts global temperatures, cloud formation, and the health of our oceans. The Earth Surface Mineral Dust Source Investigation, or EMIT, is the first instrument of its kind, designed to collect measurements from space of some of the most arid regions on Earth to understand the composition of soils that generate dust and the larger role dust plays in climate change.

Read on to find out how the instrument works and why scientists are hoping to learn more about the composition of dust. Then, explore how to bring the science into your classroom with related climate lessons that bridge physical sciences with engineering practices.

Why It’s Important

Scientists have long studied the movements of dust. The fact that dust storms can carry tiny particles great distances was reported in the scientific literature nearly two centuries ago by none other than Charles Darwin as he sailed across the Atlantic on the HMS Beagle. What still remains a mystery all these years later is what that dust is made of, how it moves, and how that affects the health of our planet.

For example, we now know that dust deposited on snow speeds up snow melt even more than increased air temperature. That is to say, that dust traveling to cold places can cause increased snow melt.

Sharp mountain peaks are covered in splotches of snow with a fine coating of dust visible on top of the snow.

A coating of dust on snow speeds the pace of snowmelt in the spring. Credit: NASA | + Expand image

Dust can affect air temperatures as well. For example, dust with more iron absorbs light and can cause the air to warm, while dust with less iron reflects light and is responsible for local cooling. Iron in dust can also act as a fertilizer for plankton in oceans, supplying them with nutrients needed for growth and reproduction.

A plume of dust eminates from over the Copper River in Alaska, spreading out as this series of overhead satellite images progresses.

A plume of dust is shown emanating from over Alaska's Copper River in October 2016 in these images captured by the Moderate Resolution Imaging Spectroradiometer, or MODIS, instrument on NASA’s Terra and Aqua satellites. Dust storms play a key role in fueling phytoplankton blooms by delivering iron to the Gulf of Alaska. Credit: NASA | › Full image and caption

Floating dust potentially alters the composition of clouds and how quickly or slowly they form, which can ultimately impact weather patterns, including the formation of hurricanes. That’s because clouds need particles to act as seeds around which droplets of moisture in the atmosphere can form. This process of coalescing water particles, called nucleation, is one factor in how clouds form.

An overhead view of a swirl of clouds mixed with a streak of dust like a swirl of milk froth in a cappuccino

A swirl of dust mixes with the clouds in a low-pressure storm over the Gobi desert between Mongolia and China. This image was captured by the MODIS instrument on the Terra satellite in May 2019. Credit: NASA | › Full image and caption

Thanks to EMIT, we’ll take the first steps in understanding how the movements of dust particles contribute to local and global changes in climate by producing “mineral maps”. These mineral maps will reveal differences in the chemical makeup of dust, providing essential information to help us model the way dust can transform Earth’s climate.

› Learn more about what EMIT will do from JPL News

How It Works

NASA has been exploring how dust moves across the globe by combining on-the-ground field studies with cutting-edge technology.

Dr. Olga Kalashnikova, an aerosol scientist at NASA's Jet Propulsion Laboratory and a co-investigator for EMIT, has been using satellite data to study atmospheric mineral dust for many years, including tracking the movements of dust and investigating trends in the frequency of dust storms.

As Dr. Kalashnikova describes, “From the ground, we can see what types of dusts are lifted into the atmosphere by dust storms on a local scale, but with EMIT, we can understand how they differ and where they originally came from.”

EMIT is the first instrument designed to observe a key part of the mineral dust cycle from space, allowing scientists to track different dust compositions on a global scale, instead of in just one region at a time. To understand dust’s impact on Earth’s climate, scientists will use EMIT to answer key questions, including:

  • How does dust uplifted in the atmosphere alter global temperatures?
  • What role do dusts play in fertilizing our oceans when they are deposited?
  • How do dust particles in the atmosphere affect cloud nucleation; the process by which clouds are ‘seeded’ and begin to coalesce into larger clouds?
A picture of the EMIT instrument, shaped like a small megaphone, is overlaid on an picture of the International Space Station flying above Earth.

The EMIT instrument will fly aboard the International Space Station, which orbits Earth about once every 90 minutes, completing about 16 orbits per day. Credit: NASA | + Expand image

To achieve its objectives, EMIT will spend 12 months collecting what are called “hyperspectral images” of some of the most arid regions of our planet selected by scientists and engineers as areas of high dust mobility, such as Northern Africa, the Middle East, and the American Southwest.

These images are measurements of light reflected from the Earth below, calibrated to the distinct patterns, or spectra, of light we see when certain minerals are present. The EMIT team has identified 10 minerals that are most common, including gypsum, hematite, and kaolinite.

Bands of satellite images looking at a seciton of Earth are highlighted in different colors to reveal different concentrations of minerals.

This example spectra shows how scientists will be able to identify different concentrations of minerals and elements in data collected by EMIT. Credit: NASA/JPL-Caltech | + Expand image

Why are these minerals important? One key reason is the presence or absence of the element iron, found in some minerals but not others.

Dr. Bethany Ehlmann is a planetary scientist and co-investigator for the EMIT project at Caltech and explains that when it comes to heating, “a little bit of iron goes a long way.” Iron in minerals absorbs visible and infrared light, meaning that even if only a small amount is present, it will result in a much warmer dust particle. Large amounts of warm dust in our atmosphere may have an impact on temperatures globally since those dust particles radiate heat as they travel, sometimes as far as across oceans!

Collecting images from space is, of course, no easy task, especially when trying to look only at the ground below. Yet it does allow scientists to get a global picture that's not possible to capture from the ground. Field studies allow us to take individual samples from tiny places of interest, but from space, we can scan the entire planet in remote places where no scientist can visit.

Of course, there are some complications in trying to study the light reflected off the surface of Earth, such as interference from clouds. To prevent this problem, the EMIT team plans to collect data at each location several times to ensure that the images aren’t being obscured by clouds between the instrument and the minerals we’re looking for.

The data collected by EMIT will provide a map of the compositions of dust from dry, desert environments all over the world, but the team involved won’t stop there. Knowing more about what the dust is made of sets the stage for a broader understanding of a few more of the complex processes that make up our global climate cycle. Upon completion of this study, EMIT's mineral maps will support further campaigns to complete our global dust picture. For example, NASA hopes to couple the data from EMIT with targeted field campaigns, in which scientists can collect wind-blown dust from the ground to learn more about where dust particles move over time and answer questions about what types of dust are on the go.

Furthermore, missions such as the Multiangle Imager for Aerosols, or MAIA, will allow us to better understand the effects of these dust particles on air-quality and public health.

Teach it

Studying Earth’s climate is a complex puzzle, consisting of many trackable features. These can range from sea level to particles in our atmosphere, but each makes a contribution to measuring the health of our planet. Bring EMIT and NASA Earth Science into your classroom with these lessons, articles, and activities to better understand how we’re exploring climate change.

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TAGS: Earth, climate, geology, weather, EMIT, Teachers, Classroom, Lessons, Earth Science, Climate Change, Dust, Global Warming, Educators, K-12, Teachable Moments, Climate TM

  • Brandon Rodriguez
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Just beyond the wing of a plane, the edge of a tall glacier is visible through the plane's window. At the bottom of the glacier, bits of ice surround an elliptical pool of brown water at the glacier's edge.

Explore how the OMG mission discovered more about what's behind one of the largest contributors to global sea level rise. Plus, learn what it means for communities around the world and how to get students engaged.


After six years investigating the effects of warming oceans on Greenland's ice sheet, the Oceans Melting Greenland, or OMG, mission has concluded. This airborne and seaborne mission studied how our oceans are warming and determined that ocean water is melting Greenland’s glaciers as much as warm air is melting them from above.

Read on to learn more about how OMG accomplished its goals and the implications of what we learned. Then, explore educational resources to engage students in the science of this eye-opening mission.

Why It's Important

Global sea level rise is one of the major environmental challenges of the 21st century. As oceans rise, water encroaches on land, affecting populations that live along shorelines. Around the world – including U.S. regions along the Gulf of Mexico and Eastern Seaboard and in Alaska – residents are feeling the impact of rising seas. Additionally, freshwater supplies are being threatened by encroaching saltwater from rising seas.

Sea level rise is mostly caused by melting land ice (primarily glaciers), which adds water to the ocean, as well as thermal expansion, the increase in volume that occurs when water heats up. Both ice melt and thermal expansion result from rising global average temperatures on land and in the sea – one facet of climate change.

This short video explains why Greenland's ice sheets are melting and what it means for our planet. Credit: NASA/JPL-Caltech | Watch more from the Earth Minute series

Greenland’s melting glaciers contribute more freshwater to sea level rise than any other source, which is why the OMG mission set out to better understand the mechanisms behind this melting.

How We Did It

The OMG mission used a variety of instruments onboard airplanes and ships to map the ocean floor, measure the behemoth Greenland glaciers, and track nearby water temperature patterns.

Join JPL scientist Josh Willis as he and the NASA Oceans Melting Greenland (OMG) team work to understand the role that ocean water plays in melting Greenland’s glaciers. Credit: NASA/JPL-Caltech | Watch on YouTube

An animation shows a ship passing over the ocean directly in front of a glacier and scanning the sea floor followed by a plane flying overhead and scanning the air.

This animation shows how the OMG mission created a map of the ocean floor, known as a bathymetric map, to determine the geometry around Greenland's glaciers. Image credit: NASA/JPL-Caltech | + Expand image

An animation shows a plan flying over a glacier and scanning the ground below followed by a plane flying over the ocean shelf next to the glacier and dropping probes into the water.

This animation shows how the OMG mission used radar to measure changes in the thickness and retreat of Greenland's glaciers as well as probes to measure ocean temperature and salinity. Credit: NASA/JPL-Caltech | + Expand image

Early on, the mission team created a map of the ocean floor, known as a bathymetric map, by combining multibeam sonar surveys taken from ships and gravity measurements taken from airplanes. Interactions among glaciers and warming seas are highly dependent on the geometry of the ocean floor. For example, continental shelf troughs carved by glaciers allow pathways for water to interact with glacial ice. So understanding Greenland's local bathymetry was crucial to OMG's mission.

To locate the edges of Greenland's glaciers and measure their heights, the mission used a radar instrument known as the Glacier and Ice Surface Topography Interferometer. Every spring during the six-year OMG mission, the radar was deployed on NASA’s Gulfstream III airplane that flew numerous paths over Greenland’s more than 220 glaciers. Data from the instrument allowed scientists to determine how the thickness and area of the glaciers are changing over time.

Finally, to measure ocean temperature and salinity patterns, scientists deployed numerous cylindrical probes. These probes dropped from an airplane and fell through the water, taking measurements from the surface all the way to the ocean floor. Each probe relayed its information back to computers onboard the plane where ocean temperatures and salinity were mapped. Then, scientists took this data back to their laboratories and analyzed it for trends, determining temperature variations and circulation patterns.

What We Discovered

Prior to the OMG mission, scientists knew that warming air melted glaciers from above, like an ice cube on a hot day. However, glaciers also flow toward the ocean and break off into icebergs in a process called calving. Scientists had the suspicion that warmer ocean waters were melting the glaciers from below, causing them to break off more icebergs and add to rising seas. It wasn’t until they acquired the data from OMG, that they discovered the grim truth: Glaciers are melting from above and below, and warming oceans are having a significant effect on glacial melt.

This narrated animation shows warm ocean water is melting glaciers from below, causing their edges to break off in a process called calving. Credit: NASA | Watch on YouTube

What this means for our Earth's climate is that as we continue burning fossil fuels and contributing to greenhouse gas accumulation, the oceans, which store more than 90% of the heat that is trapped by greenhouse gases, will continue to warm, causing glaciers to melt faster than ever. As warming ocean water moves against glaciers, it eats away at their base, causing the ice above to break off. In other words, calving rates increase and sea level rises even faster.

Our oceans control our climate and affect our everyday lives, whether or not we live near them. With the pace of the melt increasing, our shorelines and nearby communities will be in trouble sooner than previously expected. And it’s not just the beaches that will be affected. If Greenland’s glaciers all melt, global sea levels will rise by over 24 feet (7.4 meters), bringing dramatic change to the landscapes of major cities around the world.

› Read more about OMG’s findings and how scientists are continuing their research through ongoing initiatives and projects.

Teach It

Check out these resources to bring the real-life STEM behind the mission into your teaching. With lessons for educators and student projects, engage students in learning about the OMG mission and NASA climate science.

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TAGS: Teachable Moment, Climate, Earth Science, Glaciers, Greenland, Ice, Sea Level Rise, Teachers, Educators, Parents, Lessons, Missions, Earth, Climate TM

  • Ota Lutz
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Collage of images and graphics representing the science goals of the Sentinel-6 Michael Freilich mission

Learn about the mission and find out how to make classroom connections to NASA Earth science – plus explore related teaching and learning resources.


In the News

A new spacecraft that will collect vital sea-surface measurements for better understanding climate change and improving weather predictions is joining the fleet of Earth science satellites monitoring our changing planet from space. A U.S.-European partnership, the Sentinel-6 Michael Freilich satellite continues a long tradition of collecting scientific data from Earth orbit. It’s named in honor of NASA’s former Earth Science Division director and a leading advocate for ocean measurements from space.

Read on to find out how the mission will measure sea-surface height for the next 10 years and provide atmospheric data to help better predict weather. Plus, find out how to watch the launch online and explore related teaching resources to bring NASA Earth science into the classroom and incorporate sea level data into your instruction.

How It Works

The Sentinel-6 Michael Freilich satellite is designed to measure sea-surface height and improve weather predictions. Once in orbit, it will be able to measure sea-surface height – with accuracy down to the centimeter – over 90% of the world’s oceans every 10 days. It will do this using a suite of onboard science tools, or instruments.

To measure sea-surface height, a radar altimeter will send a pulse of microwave energy to the ocean’s surface and record how long it takes for the energy to return. The time it takes for the signal to return varies depending on the height of the ocean – a higher ocean surface results in a shorter return time, while a lower ocean surface results in a longer return time. A microwave radiometer will measure delays that take place as the signal travels through the atmosphere to correct for this effect and provide an even more precise measurement of sea-surface height.

A blue beam extends from the spacecraft down toward Earth as a red dot pulses back and forth between the spacecraft and the surface of the planet.

This animation shows the radar pulse from the Sentinel-6 Michael Freilich satellite's altimeter bouncing off the sea surface in order to measure the height of the ocean. Image credit: NASA/JPL-Caltech | + Expand image

To measure atmospheric data, Sentinel-6 Michael Freilich is equipped with the Global Navigation Satellite System - Radio Occultation, or GNSS-RO, instrument, which will measure signals from GPS satellites – the same ones you use to navigate on Earth. As these satellites move below or rise above the horizon from Sentinel-6 Michael Freilich's perspective, their signals slow down, change frequency and bend as a result of the phenomenon known as refraction. Scientists can use these changes in the GPS signal to measure small shifts in temperature, moisture content, and density in the atmosphere. These measurements can help meteorologists improve weather forecasts.

Why It's Important

Scientists from around the world have been collecting sea level measurements for more than a century. The data – gathered from tide gauges, sediment cores, and space satellites – paint a clear picture: sea level is rising. Looking at the average height of the sea across the planet, we see that in the last 25 years global sea level has been rising an average of 0.13 inches (3.3 mm) per year. This average is increasing each year (in the 2000s, it was 0.12 inches, or 3.0 mm, per year) as is the rate at which it’s increasing. That means that sea level is rising, and it’s rising faster and faster. Since 1880, global sea level has risen more than eight inches (20 cm). By 2100, it is projected to rise another one to four feet (30 to 122 cm).

This satellite data show the change in Earth's global sea level since 1993. Roll over the chart to see the various data points. For more Earth vital signs, visit NASA's Global Climate Change website

Measuring sea level from space provides scientists with global measurements of Earth’s oceans in a matter of days, including areas far from shore where measurements aren’t practical or possible. Starting in 1992 with the launch of the TOPEX/Poseidon mission, the record of sea level measurements from space has continued uninterrupted, providing an increasingly detailed picture of Earth’s rising seas. The Sentinel-6 Michael Freilich satellite – and its twin, which will launch in 2025 – will extend those measurements to 2030, allowing scientists to continue collecting vital information about Earth’s changing oceans and climate.

Unlike previous satellites that measured sea level, Sentinel-6 Michael Freilich has the capability to measure sea level variations more accurately near coastlines, giving scientists insight into changes that can have direct impacts on communities and livelihoods, such as commercial fishing and ship navigation.

This playlist for students and teachers features explainers about the causes and effects of sea level rise and how NASA is studying our changing planet – plus related STEM activities and experiments for students. | Watch on YouTube

With rising seas already impacting people and communities, it's important to understand not just how much seas are rising, but also where and how quickly they are rising. Data from instruments on Sentinel-6 Michael Freilich can be combined with data from other satellites to get a clearer picture of what's contributing to sea level rise and where. For example, by looking at the satellite's radar altimeter measurements along with gravity measurements from the GRACE-FO mission, scientists can better determine how melting ice and thermal expansion are contributing to sea level rise. And by tracking the movement of warm water (which stands taller than cold water), scientists can better predict the rapid expansion of hurricanes.

Watch the Launch

Scheduled to launch at 9:17 a.m. PST (12:17 p.m. EST) on November 21, Sentinel-6 Michael Freilich will launch atop a SpaceX Falcon 9 rocket from Vandenberg Air Force Base in California.

Watch a live broadcast of the launch from the Vandenberg Air Force Base on NASA TV and the agency’s website. Visit the Sentinel-6 Michael Freilich website to explore more news about the mission. Follow launch updates on NASA's Twitter, Facebook and Instagram accounts.

Teach It

Make classroom connections to NASA Earth science with lessons about rising seas, thermal expansion and ice melt, data collection and graphing, and engineering. Plus explore independent activities and experiments students can do at home, video playlists, and more:

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TAGS: Teachable Moments, Educators, Teachers, Parents, K-12 Education, Launch, Mission, Earth, Satellite, Earth Science, Climate Change, Sentinel-6 Michael Freilich, Sea Level, Sea Level Rise, Climate TM

  • Lyle Tavernier
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Satellite Image of smoke above the Western U.S.

Data overlayed on a satellite image of the United States shows a thick cloud of aerosols over the western US

Animated satellite image of Earth

Update: Sept. 14, 2020 – This feature, originally published on Aug. 23, 2016, has been updated to include information on the 2020 fires and current fire research.


In the News

Once again, it’s fire season in the western United States with many citizens finding themselves shrouded in wildfire smoke. Late summer in the West brings heat, low humidity, and wind – optimal conditions for fire. These critical conditions have resulted in the August Complex Fire, the largest fire in California's recorded history. Burning concurrently in California are numerous other wildfires, including the SCU Lightning Complex fire, the third-largest in California history.

Fueled by high temperatures, low humidity, high winds, and years of vegetation-drying drought, more than 7,700 fires have engulfed over 3 million acres across California already this year. And the traditional fire season – the time of year when fires are more likely to start, spread, and consume resources – has only just begun.

Because of their prevalence and effects on a wide population, wildfires will remain a seasonal teachable moment for decades to come. Keep reading to find out how NASA studies wildfires and their effects on climate and communities. Plus, explore lessons to help students learn more about fires and their impacts.

How It Works

With wildfires starting earlier in the year and continuing to ignite throughout all seasons, fire season is now a year-round affair not just in California, but also around the world. In fact, the U.S. Forest Service found that fire seasons have grown longer in 25 percent of Earth's vegetation-covered areas.

Animation of the FireSat network of satellites capturing wildfires on Earth

This animation shows how FireSat would use a network of satellites around the Earth to detect fires faster than ever before. | + Expand image

For NASA's Jet Propulsion Laboratory, which is located in Southern California, the fires cropping up near and far are a constant reminder that its efforts to study wildfires around the world from space, the air, and on the ground are as important as ever.

JPL uses a suite of Earth satellites and airborne instruments to help better understand fires and aide in fire management and mitigation. By looking at multiple images and types of data from these instruments, scientists compare what a region looked like before, during, and after a fire, as well as how long the area takes to recover.

While the fire is burning, scientists watch its behavior from an aerial perspective to get a big-picture view of the fire itself and the air pollution it is generating in the form of smoke filled with carbon monoxide and carbon dioxide.

Natasha Stavros, a wildfire expert at JPL, joined Zach Tane with the U.S. Forest Service during a Facebook Live event to discuss some of these technologies and how they're used to understand wildfire behavior and improve wildfire recovery.

Additionally, JPL worked with a startup in San Francisco called Quadra Pi R2E to develop FireSat, a global network of satellites designed to detect wildfires and alert firefighting crews faster. 

Using these technologies, NASA scientists are gaining a broader understanding of fires and their impacts.

Why It's Important

One of the ways we often hear wildfires classified is by how much area they have burned. Though this is certainly of some importance, of greater significance to fire scientists is the severity of the fire. Wildfires are classified as burning at different levels of severity: low, medium, and high. Severity is a function of intensity, or how hot the fire was, and its spread rate, or the speed at which it travels. A high-severity fire is going to do some real damage. (Severity is measured by the damage left after the fire, but can be estimated during a fire event by calculating spread rate and measuring flame height which indicates intensity.)

Google Earth image showing fire severity
This image, created using data imported into Google Earth, shows the severity of the 2014 King Fire. Green areas are unchanged by the fire; yellow equals low severity; orange equals moderate severity; and red equals high severity. A KMZ file with this data is available in the Fired Up Over Math lesson linked below. Credit: NASA/JPL-Caltech/E. Natasha Stavros.

The impacts of wildfires range from the immediate and tangible to the delayed and less obvious. The potential for loss of life, property, and natural areas is one of the first threats that wildfires pose. From a financial standpoint, fires can lead to a downturn in local economies due to loss of tourism and business, high costs related to infrastructure restoration, and impacts to federal and state budgets.

The release of greenhouse gases like carbon dioxide and carbon monoxide is also an important consideration when thinking about the impacts of wildfires. Using NASA satellite data, researchers at the University of California, Berkeley, determined that between 2001 and 2010, California wildfires emitted about 46 million tons of carbon, around five to seven percent of all carbon emitted by the state during that time period.

Animation showing Carbon Dioxide levels rising from the Station Fire in Southern California.
This animation from NASA's Eyes on the Earth visualization program shows carbon monoxide rising (red is the highest concentration) around Southern California as the Station Fire engulfed the area near JPL in 2009. Image credit: NASA/JPL-Caltech

In California and the western United States, longer fire seasons are linked to changes in spring rains, vapor pressure, and snowmelt – all of which have been connected to climate change. Wildfires serve as a climate feedback loop, meaning certain effects of wildfires – the release of CO2 and CO – contribute to climate change, thereby enhancing the factors that contribute to longer and stronger fire seasons.

While this may seem like a grim outlook, it’s worth noting that California forests still act as carbon sinks – natural environments that are capable of absorbing carbon dioxide from the atmosphere. In certain parts of the state, each hectare of redwood forest is able to store the annual greenhouse gas output of 500 Americans.

Studying and managing wildfires is important for maintaining resources, protecting people, properties, and ecosystems, and reducing air pollution, which is why JPL, NASA, and other agencies are continuing their study of these threats and developing technologies to better understand them.

Teach It

Have your students try their hands at solving some of the same fire-science problems that NASA scientists do with these two lessons that get students in grades 3 through 12 using NASA data, algebra, and geometry to approximate burn areas, fire-spread rate and fire intensity:

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Lyle Tavernier contributed to this feature.

TAGS: teachable moments, wildfires, science, Earth Science, Earth, Climate Change, Climate TM

  • Ota Lutz
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Illustration of spacecraft on a light purple background that reads "NASA Pi Day Challenge"

Update: March 16, 2020 – The answers to the 2020 NASA Pi Day Challenge are here! View the illustrated answer key (also available as a text-only doc).


In the News

Our annual opportunity to indulge in a shared love of space exploration, mathematics and sweet treats has come around again! Pi Day is the March 14 holiday that celebrates the mathematical constant pi – the number that results from dividing any circle's circumference by its diameter.

Infographic of all of the Pi in the Sky 7 graphics and problems

Visit the Pi in the Sky 7 lesson page to explore classroom resources and downloads for the 2019 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

Overhead view of Mars with a comparison of the smaller landing ellipse made possible by Range Trigger technology

A new Mars landing technique called Range Trigger is reducing the size of the ellipse where spacecraft touch down. Image credit: NASA/JPL-Caltech | › Full image and caption

Composite image of the Kuiper Belt object Arrokoth from NASA's New Horizons spacecraft. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko | › Full image and caption

Diagram of an airplane flying over a section of ocean with an example of the spectral data that CORAL collects

The CORAL mission records the spectra of light reflected from the ocean to study the composition and health of Earth's coral reefs. Image credit: NASA | + Expand image

Rays of bright orange and red shoot out diagonally from a blue circle surrounding the star Beta Pictoris

The star Beta Pictoris and its surrounding debris disk in near-infrared light. Image credit: ESO/A.-M. Lagrange et al. | › Full image and caption

Besides providing an excuse to eat all varieties of pie, Pi Day gives us a chance to appreciate some of the ways NASA uses pi to explore the solar system and beyond. You can do the math for yourself – or get students doing it – by taking part in the NASA Pi Day Challenge. Find out below how to test your pi skills with real-world problems faced by NASA space explorers, plus get lessons and resources for educators.

How It Works

The ratio of any circle's circumference to its diameter is equal to pi, which is often rounded to 3.14. But pi is what is known as an irrational number, so its decimal representation never ends, and it never repeats. Though it has been calculated to trillions of digits, we use far fewer at NASA.

Pi is useful for all sorts of things, like calculating the circumference and area of circular objects and the volume of cylinders. That's helpful information for everyone from farmers irrigating crops to tire manufacturers to soup-makers filling their cans. At NASA, we use pi to calculate the densities of planets, point space telescopes at distant stars and galaxies, steer rovers on the Red Planet, put spacecraft into orbit and so much more! With so many practical applications, it's no wonder so many people love pi!

In the U.S., 3.14 is also how we refer to March 14, which is why we celebrate the mathematical marvel that is pi on that date each year. In 2009, the U.S. House of Representatives passed a resolution officially designating March 14 as Pi Day and encouraging teachers and students to celebrate the day with activities that teach students about pi.

The NASA Pi Day Challenge

This year's NASA Pi Day Challenge poses four puzzlers that require pi to compare the sizes of Mars landing areas, calculate the length of a year for one of the most distant objects in the solar system, measure the depth of the ocean from an airplane, and determine the diameter of a distant debris disk. Learn more about the science and engineering behind the problems below or click the link to jump right into the challenge.

› Take the NASA Pi Day Challenge
› Educators, get the lesson here!

Mars Maneuver

Long before a Mars rover touches down on the Red Planet, scientists and engineers must determine where to land. Rather than choosing a specific landing spot, NASA selects an area known as a landing ellipse. A Mars rover could land anywhere within this ellipse. Choosing where the landing ellipse is located requires compromising between getting as close as possible to interesting science targets and avoiding hazards like steep slopes and large boulders, which could quickly bring a mission to its end. In the Mars Maneuver problem, students use pi to see how new technologies have reduced the size of landing ellipses from one Mars rover mission to the next.

Cold Case

In January 2019, NASA's New Horizons spacecraft sped past Arrokoth, a frigid, primitive object that orbits within the Kuiper Belt, a doughnut-shaped ring of icy bodies beyond the orbit of Neptune. Arrokoth is the most distant Kuiper Belt object to be visited by a spacecraft and only the second object in the region to have been explored up close. To get New Horizons to Arrokoth, mission navigators needed to know the orbital properties of the object, such as its speed, distance from the Sun, and the tilt and shape of its orbit. This information is also important for scientists studying the object. In the Cold Case problem, students can use pi to determine how long it takes the distant object to make one trip around the Sun.

Coral Calculus

Coral reefs provide food and shelter to many ocean species and protect coastal communities against extreme weather events. Ocean warming, invasive species, pollutants, and acidification caused by climate change can harm the tiny living coral organisms responsible for building coral reefs. To better understand the health of Earth's coral reefs, NASA's COral Reef Airborne Laboratory, or CORAL, mission maps them from the air using spectroscopy, studying how light interacts with the reefs. To make accurate maps, CORAL must be able to differentiate among coral, algae and sand on the ocean floor from an airplane. And to do that, it needs to calculate the depth of the ocean at every point it maps by measuring how much sunlight passes through the ocean and is reflected upward from the ocean floor. In Coral Calculus, students use pi to measure the water depth of an area mapped by the CORAL mission and help scientists better understand the status of Earth's coral reefs.

Planet Pinpointer

Our galaxy contains billions of stars, many of which are likely home to exoplanets – planets outside our solar system. So how do scientists decide where to look for these worlds? Using data gathered by NASA's Spitzer Space Telescope, researchers found that they're more likely to find giant exoplanets around young stars surrounded by debris disks, which are made up of material similar to what's found in the asteroid belt and Kuiper Belt in our solar system. Sure enough, after discovering a debris disk around the star Beta Pictoris, researchers later confirmed that it is home to at least two giant exoplanets. Learning more about Beta Pictoris' debris disk could give scientists insight into the formation of these giant worlds. In Planet Pinpointer, put yourself in the role of a NASA scientist to learn more about Beta Pictoris' debris disk, using pi to calculate the distance across it.

Participate

Join the conversation and share your Pi Day Challenge answers with @NASAJPL_Edu on social media using the hashtag #NASAPiDayChallenge

Blogs and Features

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NOAA Video Series: Coral Comeback

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TAGS: K-12 Education, Math, Pi Day, Pi, NASA Pi Day Challenge, Events, Space, Educators, Teachers, Parents, Students, STEM, Lessons, Problem Set, Mars 2020, Perseverance, Curiosity, Mars rovers, Mars landing, MU69, Arrokoth, New Horizons, Earth science, Climate change, CORAL, NASA Expeditions, coral reefs, oceans, Spitzer, exoplanets, Beta Pictoris, stars, universe, space telescope, Climate TM

  • Lyle Tavernier
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Side-by-side satellite and data images of soil moisture, flooding, temperature, a snowstorm, a wildfire and a hurricane

In the News

An extreme weather event is something that falls outside the realm of normal weather patterns. It can range from superpowerful hurricanes to torrential downpours to extended hot dry weather and more. Extreme weather events are, themselves, troublesome, but the effects of such extremes, including damaging winds, floods, drought and wildfires, can be devastating.

NASA uses airborne and space-based platforms, in conjunction with those from the National Oceanic and Atmospheric Administration, or NOAA, to monitor these events and the ways in which our changing climate is contributing to them. Together, the agencies are collecting more detailed data on weather and climate than ever before, improving society's ability to predict, monitor and respond to extreme events.

NASA makes this data available to the public, and students can use it to understand extreme weather events happening in their regions, learn more about weather and climate in general, and design plans for resilience and mitigation. Read on for a look at the various kinds of extreme weather, how climate change is impacting them, and ways students can use NASA data to explore science for themselves.

How It Works

Global climate change, or the overall warming of our planet, has had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up and melting earlier in the year, precipitation patterns have changed, plant and animal habitat ranges have shifted, and trees are flowering sooner, exposing fruit blossoms to damaging erratic spring hail and deadly late frost. Effects that scientists had predicted in the past are now occurring: loss of sea ice, accelerated sea level rise, shifting storm patterns and longer, more intense heat waves.

Some of the most visible and disruptive effects of global climate change are extreme weather and resulting disasters such as wildfires and flooding. These events vary by geographic location, with many regions, such as the Southwest United States and parts of Central and South America, Asia, Europe, Africa and Australia, experiencing more heat, drought and insect outbreaks that contribute to increased wildfires. Other regions of the world, including coastal areas of the United States and many island nations, are experiencing flooding and salt water intrusion into drinking water wells as a result of sea level rise and storm surges from intense tropical storms. And some areas of the world, such as the Midwestern and Southern United States, have been inundated with rain that has resulted in catastrophic flooding.

Side-by-side images showing the river on a typical day and the river flooded

This pair of images shows the northeast side of Tulsa, Oklahoma, in May 2018 (left) and in May 2019 (right) after the Caney and Verdigris rivers flooded. Image credit: NASA/USGS | › Full image and caption

Temperatures, rainfall, droughts, high-intensity hurricanes and severe flooding events all are increasing and projected to continue as the world's climate warms, according to the National Climate Assessment. Weather is dynamic and various types of weather can interact to produce extreme outcomes. Here's how climate change can play a role in some of these weather extremes.

High Temperatures

This color-coded map displays a progression of changing global surface temperature anomalies from 1880 through 2018. Higher-than-normal temperatures are shown in red and lower-than-normal temperatures are shown in blue. The final frame represents the global temperatures five-year averaged from 2014 through 2018. Scale in degrees Celsius. Credit: NASA's Scientific Visualization Studio. Data provided by Robert B. Schmunk (NASA/GSFC GISS). | Watch on YouTube

Eighteen of the 19 warmest years on record have occurred since 2001. September 2019 tied as the hottest month on record for the planet. Since the 1880s, the average global surface temperature has risen about 2 degrees Fahrenheit (1 degree Celsius). As a result of warming temperatures, global average sea level has risen nearly 7 inches (178 millimeters) over the past 100 years. Data show this warming of the Earth system has been driven in large part by increased emissions into the atmosphere of carbon dioxide and other greenhouse gases created by human activities. And as temperatures continue to rise, we can expect more extreme weather.

Drought and Wildfires

Side-by-side images showing red areas throughout Alaska representing hotter than usual temperatures and a satellite image showing smoke and clouds coming from the same areas

The image on the left shows air temperatures during a record-breaking June 2019 heat wave in Alaska. Around the same time, a cluster of lightning-triggered wildfires broke out in the same area. Smoke from the wildfires can be seen in the image on the right. Image credit: NASA | › Full image and caption

High temperatures alone can lead to drought. Drought can cause problems for humans, animals and crops dependent on water and can weaken trees, making them more susceptible to disease and insect attacks. High temperatures combined with low humidity, dry vegetation and hot, dry, fast winds typify what is known as "fire weather" or "fire season." During fire season, wildfires are more likely to start, spread rapidly and be difficult to extinguish.

A satellite image of Northern California showing a dark reddish brown section with smoke eminating from it

The Operational Land Imager on the Landsat 8 satellite captured this image of the Walker Fire in Northern California on Sept. 8, 2019. Image credit: NASA/USGS | › Full image and caption

In California, where climate change has brought hotter, drier weather, residents are plagued by two fire seasons – one lasting from June through September that is primarily caused by high heat, low humidity and dry vegetation, and another lasting from October through April that is generally more volatile, as it is fueled by high winds. This 11-month fire season is longer than in past years. In recent years, California has also seen an increase in destructive wildfires. Weather extremes and climate change are partly to blame, even in relatively wet years. In California, these years mean more plant growth and potentially more fuel for fires when those plants dry out in the fall and the winds arrive. Wildfires have some fairly obvious effects on people and property. In addition to the visible destruction, smoke from wildfires can dramatically decrease air quality, pushing carbon into the air and destroying important carbon-sequestering plants and trees. Large-scale biomass destruction, as is happening in the Amazon rainforest, will have a lasting impact on important Earth processes.

Hurricanes

Satellite image of a hurricane heading towards Japan

This image, acquired on October 11, 2019, by the Moderate Resolution Imaging Spectroradiometer, or MODIS, on NASA's Aqua satellite, shows Typhoon Hagibis as its outer cloud bands neared Japan. Image credit: NASA | › Full image and caption

Since the 1980s, regions of the world prone to hurricanes, cyclones and typhoons have witnessed an increase in intensity, frequency and duration of these destructive storms. All three are intense tropical storms that form over oceans. (The different names refer to where on Earth they occur.) They are all fueled by available heat energy from warm ocean water. Warmer oceans provide more energy to passing storms, meaning hurricanes can form more quickly and reach higher speeds. Typhoon Hagibis, which recently left a trail of destruction in Japan, was described as the worst storm to hit the region in decades. Growing unusually quickly from a tropical storm to a Category 5 storm in less than a day, Hagibis was so intense it was called a super typhoon. In 2018, the second strongest cyclone to hit a U.S. territory and the largest typhoon of the year, Super Typhoon Yutu, caused catastrophic destruction on the Mariana Islands, an archipelago in the North Pacific Ocean. More intense storms and rising sea levels make storm surge – ocean water that is pushed toward the shore by strong winds – even worse than in the past. Typhoons can wreak havoc on infrastructure and compromise fresh water reserves. It can take months or even years for a hard-hit region to recover.

Snowstorms

Satellite image of white snow clouds and snow over the Mid-Alantic U.S.

The MODIS instrument aboard NASA's Terra Satellite captured the low-pressure area near New England that brought heavy snows and thundersnow to the Mid-Atlantic and Northeastern U.S. in January 2011. Image credit: NASA Goddard/MODIS Rapid Response Team | › Full image and caption

Like any other weather event, extreme cold weather events such as blizzards and unusually heavy snowfall can be, but are not always, linked to climate change. Just as warmer ocean water increases the intensity of a warm tropical storm, warmer than average winter ocean temperatures in the Atlantic feed additional energy and moisture into cold storms, influencing the severity of snowfall once the storm comes ashore in the Eastern United States. There is some natural variability, such as the presence of El Niño conditions, that can also lead to severe snowstorms in the region. But natural variability isn't enough to fully explain the increase in major snowstorms in the U.S. In fact, the frequency of extreme snowstorms in the eastern two-thirds of the region has increased dramatically over the last century. Approximately twice as many extreme snowstorms occurred in the U.S. during the latter half of the 20th century as in the first half.

Why It's Important

Because of the risk to lives and property, monitoring the increasing number of extreme weather events is more important now than ever before. And a number of NASA satellites and airborne science instruments are doing just that.

Artist's concept of dozens of satellites circling Earth with a glare from the Sun in the background

This graphic shows NASA's fleet of Earth-science satellites designed to monitor weather and climate across the globe. Image credit: NASA | › Full image and caption

A large global constellation of satellites, operated by NASA and NOAA, combined with a small fleet of planes operated by the U.S. Forest Service, help detect and map the extent, spread and impact of forest fires. As technology has advanced, so has the value of remote sensing, the science of scanning Earth from a distance using satellites and high-flying airplanes. Wildfire data from satellites and aircraft provide information that firefighters and command centers can use to call evacuation orders and make decisions about where to deploy crews to best arrest a fire's progress.

The agencies' satellites and airborne instruments also work in conjunction with those from international partners to provide data about hurricanes to decision makers at the National Hurricane Center, where predictions and warnings are issued so evacuations can be coordinated among the public and local authorities. Visible imagery from NASA satellites helps forecasters understand whether a storm is brewing or weakening based on changes to its structure. Other instruments on NASA satellites can measure sea surface characteristics, wind speeds, precipitation, and the height, thickness and inner structure of clouds.

Three side-by-side data images of the hurricane from different perspectives with colors overlayed to represent various science data

Three images of Hurricane Dorian, as seen by a trio of NASA's Earth-observing satellites in August 2019. The data sent by the spacecraft revealed in-depth views of the storm, including detailed heavy rain, cloud height and wind. Image credit: NASA/JPL-Caltech | › Full image and caption

NASA's airborne instruments, such as those aboard the Global Hawk aircraft, provide data from within the storm that cannot be otherwise obtained. Global Hawk can fly above a storm in a back-and-forth pattern and drop instruments called dropsondes through the storm. These instruments measure winds, temperature, pressure and humidity on their way to the surface. This detailed data can be used to characterize a storm, informing scientists of shifting patterns and potential future developments.

NASA missions will continue to study both weather and climate phenomena – whether they be droughts, floods, wildfires, hurricanes or other extremes – returning data for analysis. New airborne instruments aboard the satellite-simulating ER-2 and cloud-penetrating P-3 aircraft will fly missions starting in 2020 to study Atlantic coast-threatening snowstorms. Data from these flights will be combined with ground-based radar measurements and satellite measurements to better understand storms and their potential impact. Meanwhile, climate science instruments and satellites will continue to collect data that can inform everyone about the many aspects of our changing planet.

Teach It

Weather and climate data isn't just for meteorologists. Explore the resources and standards-aligned lessons below to get students analyzing local weather patterns, understanding wildfire monitoring and modeling global climate!

Precipitation and Clouds

Wildfires and Temperature

Sea Level

Satellites and Data

Climate

For Students

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Resources for Students

TAGS: Earth, Earth science, climate change, weather, extreme weather, hurricane, wildfire, typhoons, drought, flood, sea level rise, Climate TM

  • Ota Lutz
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In the News

A pair of Earth orbiters designed to keep track of the planet's water resources and evolving water cycle is scheduled to launch this month – no earlier than May 22, 2018. The Gravity Recovery and Climate Experiment Follow-On mission, or GRACE-FO, will pick up where its predecessor, GRACE, left off when it completed its 15-year mission in 2017. By measuring changes in Earth’s gravity, the mission will track water movement around the globe, identifying risks such as droughts and floods and revealing how land ice and sea level are evolving. The GRACE-FO mission is a great way to get students asking, and answering, questions about how we know what we know about some of the major components of Earth’s water cycle: ice sheets, glaciers, sea level, and ground-water resources.

How It Works

The GRACE-FO mission, a partnership between NASA and the German Research Centre for Geosciences (GFZ), will measure small variations in Earth’s mass to track how and where water is moving across the planet. This is no easy task, as water can be solid, liquid or gas; it can be in plain sight (as in a lake or glacier); it can be in the atmosphere or hidden underground; and it’s always on the move. But one thing all this water has in common, regardless of what state of matter it is in or where it is located, is mass.

Everything that has mass exerts a gravitational force. It is this gravitational force that GRACE-FO measures to track the whereabouts of water on Earth. Most of Earth's gravitational force, more than 99 percent, does not change from one month to the next because it is exerted by Earth’s solid surface and interior. GRACE-FO is sensitive enough to measure the tiny amount that does change – mostly as a result of the movement of water within the Earth system.

GRACE-FO works by flying two spacecraft in tandem around Earth – one spacecraft trailing the other at a distance of about 137 miles (220 kilometers). By pointing their microwave ranging instruments at each other, the satellites can measure tiny changes in the distance between them – within one micron (the diameter of a blood cell) – caused by changes in Earth’s gravitational field. Scientists can then use those measurements to create a map of Earth’s global gravitational field and calculate local mass variations.

As the forward spacecraft travels over a region that has more or less mass than the surrounding areas, such as a mountain or low valley, the gravitational attraction of that mass will cause the spacecraft to speed up or slow down, slightly increasing or decreasing the relative distance between it and its trailing companion. As a result of this effect, GRACE-FO will be able to track water as it moves into or out of a region, changing the region’s mass and, therefore, its gravity. In fact, the previous GRACE spacecraft measured a weakening gravity field over several years in Central California, enabling an estimate of aquifer depletion, and in Greenland, providing accurate measurements of ice melt over more than 15 years.

Find out more about how the mission works in the video below, from JPL's "Crazy Engineering" video series:

Why It’s Important

Tracking changes in our water resources and the water cycle is important for everyone. The water cycle is one of the fundamental processes on Earth that sustains life and shapes our planet, moving water between Earth's oceans, atmosphere and land. Over thousands of years, we have developed our civilizations around that cycle, placing cities and agriculture near rivers and the sea, building reservoirs and canals to bring water to where it is needed, and drilling wells to pump water from the ground. We depend on this cycle for the water resources that we need, and as those resources change, communities and livelihoods are affected. For example, too much water in an area causes dangerous floods that can destroy property, crops and infrastructure. Too little water causes shortages, which require us to reduce how much water we use. GRACE-FO will provide monthly data that will help us study those precious water resources.

Graphic showing the amount of water in aquifers across Earth as measured by GRACE

A map of groundwater storage trends for Earth's 37 largest aquifers using GRACE data shows depletion and replenishment in millimeters of water per year. Twenty-one aquifers have exceeded sustainability tipping points and are being depleted, and 13 of these are considered significantly distressed, threatening regional water security and resilience. Image credit: NASA/JPL-Caltech

Changes to Earth’s water over multiple years are an important indicator of how Earth is responding in a changing climate. Monitoring changes in ice sheets and glaciers, surface and underground water storage, the amount of water in large lakes and rivers, as well as changes in sea level and ocean currents, provides a global view of how Earth’s water cycle and energy balance are evolving. As our climate changes and our local water resources shift, we need accurate observations and continuous measurements like those from GRACE and GRACE Follow-On to be able to respond and plan.

As a result of the GRACE mission, we have a much more accurate picture of how our global water resources are evolving in both the short and long term. GRACE-FO will continue the legacy of GRACE, yielding up-to-date water and surface mass information and allowing us to identify trends over the coming years.

Teach It

Have students interpret GRACE data for themselves:
Get students learning about global water resources:
Teach students to read, interpret and compare “heat map” representations of Earth science data:

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Try these related resources for students from NASA's Space Place:

TAGS: GRACE, Water, Water Cycle, Earth Science, Earth, Climate Change, Sea Level Rise, Climate TM

  • Ota Lutz
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Adopt the Planet campaign from NASA Earth

NASA uses a fleet of satellites and science instruments to study our changing climate. Here’s how students can use that NASA data to do Earth science of their own.

In the News

Earth Day, the day set aside each year to celebrate our planet and bring attention to the natural world, is celebrated each year on April 22. On Earth Day, people around the globe participate in events that draw attention to what we know about Earth, how it is changing, and how we can be kind to our home planet.

One of the ways that NASA participates – not just on Earth Day, but also year-round – is by collecting and analyzing science data from sensors on Earth and satellites. These data allow us to monitor the health of our planet and better understand how and why it is changing.

This year, to highlight the importance of these data, NASA is inviting people to “adopt” a portion of Earth’s surface and obtain a snapshot of some of the satellite data available for their adopted location. Even though you’ll have no legal or ownership rights to this region, it will be fun to learn about the various types of data available for different locations on Earth. Find out how you can participate.

How It Works

NASA’s fleet of Earth-observing satellites and airborne sensors provides us with data about such vital information as carbon dioxide, carbon monoxide, global land and sea temperature, ice, sea surface salinity, and chlorophyll – just to name a few. The satellites and sensors collect these data over time and from as many perspectives as possible, allowing us to discern trends in the data.

Learn about the fleet of NASA satellites and instruments studying Earth. | › Watch NASA's Earth Minute series

A snapshot of data is just one piece of a much larger puzzle because it only gives us an indication of what was happening at the exact moment that data was captured. Even data collected over a year has its limitations because local conditions may ebb and flow over longer time periods. Collecting data about multiple elements of the Earth system over decades or centuries enables us to develop correlation and causation models, powerful indicators of why trends are developing as they are. And using multiple platforms (satellite, aerial, Earth-based) to measure data enables us to validate our data sets.

Why It’s Important

Humans are dependent on a healthy and functioning Earth to survive, which means we need to keep a close eye on all Earth systems and our impacts on those systems. This process of collecting data over time from multiple perspectives, discerning trends and validating the data is crucial to understanding our planet and helping policymakers formulate actions we can take to preserve Earth for future generations.

Learn why NASA studies Earth in this one-minute video. | › Watch NASA's Earth Minute series

Teach It

First, introduce students to the kinds of data scientists use to study Earth. Participate in NASA’s Adopt the Planet campaign to receive a snapshot of Earth science data for one patch of Earth. Then encourage students to dig deeper with these standards-aligned lessons:

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TAGS: Earth Day, Climate Change, Earth Science, Lessons, Activities, K-12, Teaching, Earth, Sea Level Rise, Climate TM

  • Ota Lutz
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