Geography - Blog Posts
Earth’s Land Ice by the Numbers
“At a glacial pace” used to mean moving so slowly the movement is almost imperceptible. Lately though, glaciers are moving faster. Ice on land is melting and flowing, sending water to the oceans, where it raises sea levels.
In 2018, we launched the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) to continue a global record of ice elevation. Now, the results are in. Using millions of measurements from a laser in space and quite a bit of math, researchers have confirmed that Earth is rapidly losing ice.
16 Years
ICESat-2 was a follow-up mission to the original ICESat, which launched in 2003 and took measurements until 2009. Comparing the two records tells us how much ice sheets have lost over 16 years.
½ Inch
During those 16 years, melting ice from Antarctica and Greenland was responsible for just over a half-inch of sea level rise. When ice on land melts, it eventually finds its way to the ocean. The rapid melt at the poles is no exception.
400,000 Olympic Swimming Pools
One gigaton of ice holds enough water to fill 400,000 Olympic swimming pools. It’s also enough ice to cover Central Park in New York in more than 1,000 feet of ice.
200 Gigatons
Between 2003 and 2019, Greenland lost 200 gigatons of ice per year. That’s 80 million Olympic swimming pools reaching the ocean every year, just from Greenland alone.
118 Gigatons
During the same time period, Antarctica lost 118 gigatons of ice per year. That’s another 47 million Olympic swimming pools every year. While there has been some elevation gain in the continent’s center from increased snowfall, it’s nowhere near enough to make up for how much ice is lost to the sea from coastal glaciers.
10,000 Pulses
ICESat-2 sends out 10,000 pulses of laser light a second down to Earth’s surface and times how long it takes them to return to the satellite, down to a billionth of a second. That’s how we get such precise measurements of height and changing elevation.
These numbers confirm what scientists have been finding in most previous studies and continue a long record of data showing how Earth’s polar ice is melting. ICESat-2 is a key tool in our toolbox to track how our planet is changing.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Earth’s Land Ice by the Numbers
“At a glacial pace” used to mean moving so slowly the movement is almost imperceptible. Lately though, glaciers are moving faster. Ice on land is melting and flowing, sending water to the oceans, where it raises sea levels.
In 2018, we launched the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) to continue a global record of ice elevation. Now, the results are in. Using millions of measurements from a laser in space and quite a bit of math, researchers have confirmed that Earth is rapidly losing ice.
16 Years
ICESat-2 was a follow-up mission to the original ICESat, which launched in 2003 and took measurements until 2009. Comparing the two records tells us how much ice sheets have melted over 16 years.
½ Inch
During those 16 years, melting ice from Antarctica and Greenland was responsible for just over a half-inch of sea level rise. When ice on land melts, it eventually finds its way to the ocean. The rapid melt at the poles is no exception.
400,000 Olympic Swimming Pools
One gigaton of ice holds enough water to fill 400,000 Olympic swimming pools. It’s also enough ice to cover Central Park in New York in more than 1,000 feet of ice.
200 Gigatons
Between 2003 and 2019, Greenland lost 200 gigatons of ice per year. That’s 80 million Olympic swimming pools reaching the ocean every year, just from Greenland alone.
118 Gigatons
During the same time period, Antarctica lost 118 gigatons of ice per year. That’s another 47 million Olympic swimming pools every year. While there has been some elevation gain in the continent’s center from increased snowfall, it’s nowhere near enough to make up for how much ice is lost to the sea from coastal glaciers.
10,000 Pulses
ICESat-2 sends out 10,000 pulses of laser light a second down to Earth’s surface and times how long it takes them to return to the satellite, down to a billionth of a second. That’s how we get such precise measurements of height and changing elevation.
These numbers confirm what scientists have been finding in most previous studies and continue a long record of data showing how Earth’s polar ice is melting. ICESat-2 is a key tool in our toolbox to track how our planet is changing.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Looking 50 Years in the Future with NASA Earth Scientists
In the 50 years since the first Earth Day, the view from space has revolutionized our understanding of Earth’s interconnected atmosphere, oceans, freshwater, ice, land, ecosystems and climate that have helped find solutions to environmental challenges.
If NASA’s Earth science has changed this much in 50 years, what will it look like in 50 more years?
We asked some researchers what they thought. Here are their answers, in their own words.
Mahta Moghaddam is a professor of electrical and computer engineering at the University of Southern California. She’s building a system that helps sensors sync their measurements.
I am interested in creating new ways to observe the Earth. In particular, my team and I are building and expanding a system that will allow scientists to better study soil moisture. Soil moisture plays a vital role in the water and energy cycle and drives climate and weather patterns. When soil is wet and there is enough solar radiation, water can evaporate and form clouds, which precipitate back to Earth. Soil also feeds us – it nourishes our crops and sustains life on Earth. It’s one of the foundations of life! We need to characterize and study soil in order to feed billions of people now and in the future.
Our novel tool aims to observe changes in soil moisture using sensors that talk to each other and make decisions in real time. For instance, if one sensor in a crop field notes that soil is dry in a plot, it could corroborate it with other sensors in the area and then notify a resource manager or decision maker that an area needs water. Or if a sensor in another location senses that soil moisture is changing quickly due to rain or freeze/thaw activity, it could send a command to launch a drone or even to notify satellites to start observing a larger region. We live in one big, connected world, and can and will use many different scales of observations – local to global – from point-scale in-situ sensors to the scales that can be covered by drones, airplanes, and satellites. In just a few years from now, we might see much more vastly automated systems, with some touching not only Earth observations, but other parts of our lives, like drone deliveries of medical tests and supplies.
Odele Coddington is a scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. She’s building an instrument to measure how much solar energy Earth reflects back into space.
My research is focused on the Earth system response to the Sun’s energy. I spend half of my time thinking about the amount and variability of the Sun’s energy, also known as the solar irradiance. I’m particularly interested in the solar spectral irradiance, which is the study of the individual wavelengths of the Sun’s energy, like infrared and ultraviolet. On a bright, clear day, we feel the Sun’s warmth because the visible and infrared radiation penetrate Earth’s atmosphere to reach the surface. Without the Sun, we would not be able to survive. Although we’ve been monitoring solar irradiance for over 40 years, there is still much to learn about the Sun’s variability. Continuing to measure the solar irradiance 50 years from now will be as important as it is today.
I spend the other half of my time thinking about the many processes driven by the Sun’s energy both within the atmosphere and at the surface. I’m excited to build an instrument that will measure the integrated signal of these processes in the reflected solar and the emitted thermal radiation. This is my first foray into designing instrumentation and it has been so invigorating scientifically. My team is developing advanced technology that will measure Earth’s outgoing radiation at high spatial resolution and accuracy. Our instrument will be small from the onset, as opposed to reducing the size and mass of existing technology. In the future, a constellation of these instruments, launched on miniaturized spacecraft that are more flexible to implement in space, will give us more eyes in the sky for a better understanding of how processes such as clouds, wildfires and ice sheet melting, for instance, alter Earth’s outgoing energy.
Sujay Kumar is a research physical scientist at NASA’s Goddard Space Flight Center. He works on the Land Information System.
Broadly, I study the water cycle, and specifically the variability of its components. I lead the development of a modeling system called the Land Information System that isolates the land and tries to understand all the processes that move water through the landscape. We have conceptual models of land surface processes, and then we try to constrain them with satellite data to improve our understanding. The outputs are used for weather and climate modeling, water management, agricultural management and some hazard applications.
I think non-traditional and distributed platforms will become more the norm in the future. So that could be things like CubeSats and small sats that are relatively cheaper and quicker than large satellites in terms of how much time it takes to design and launch. One of the advantages is that because they are distributed, you’re not relying on a single satellite and there will be more coverage. I also think we’ll be using data from other “signals of opportunity” such as mobile phones and crowd-sourced platforms. People have figured out ways to, for example, retrieve Earth science measurements from GPS signals.
I feel like in the future we will be designing our sensors and satellites to be adaptive in terms of what the observational needs on the ground are. Say a fire or flood happens, then we will tell the satellite to look over there more intensely, more frequently so that we can benefit. Big data is a buzzword, but it’s becoming a reality. We are going to have a new mission call NISAR that’s going to collect so much data that we really have to rethink how traditional modeling systems will work. The analogy I think of is the development of a self-driving car, which is purely data driven, using tons and tons of data to train the model that drives the car. We could possibly see similar things in Earth science.
Hear from more NASA scientists on what they think the future will bring for Earth science:
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10 Ground-breaking Earth Satellite Images from 2018
In 2018, our satellites captured beautiful imagery from throughout the solar system and beyond. However, some of our favorite visualizations are of this very planet. While this list is by no means exhaustive, it does capture some Earth satellite images from this year that are both visually striking as well as scientifically informative. This list also represents a broad variety of Earth’s features, as well as satellite instrumentation. Take a journey with our eyes in the sky!
10. Hurricane Florence
Before making landfall, Hurricane Florence churned in the Atlantic for a full two weeks — making it among the longest-lived cyclones of the 2018 season. When it finally did hit land on Sep. 14, the storm devastated the southeastern U.S. coast with intense winds, torrential rains and severe flooding.
This natural-color image was acquired by MODIS on the Terra Satellite on Sep. 12, 2018.
Images like this, as well as other satellite information, were used to anticipate the impact of the storm. Our Disasters Program created flood proxy maps that were shared with the Federal Emergency Management Agency (FEMA) and the National Guard to estimate how many and which communities would be most affected by the storm, in order to help prepare recovery efforts ahead of time.
9. Australia’s Lake Eyre Basin
The Lake Eyre Basin covers one-sixth of Australia and is one of the world’s largest internally draining river systems. However, the rivers supported by this system are ephemeral, meaning that they only run for short periods of time following unpredictable rain — the rest of the time, the Basin is a dry, arid desert.
However, when the heavy rain comes, the basin erupts in an explosion of green. In this false-color image captured by the Operational Land Imager (OLI) on Landsat 8 on Apr. 25, 2018, you can see how the vegetation completely envelops the spaces where the water has receded. (Flood water is indicated by light blue, and vegetation is indicated by light green.)
Satellites are an excellent tool for tracking greening events that are followed by flooding. These events offer opportunities for predictive tools as well as recreation.
8. Alaska’s Chukchi Sea
A Monet painting comes to life as the Chukchi Sea swirls with microscopic marine algae.
This image was captured off the Alaskan coast by OLI on Landsat 8 on Jun. 18, 2018. After the Arctic sea ice breaks up each spring, the nutrient-rich Bering Sea water mixes with the nutrient-poor Alaskan coastal water. Each type of water brings with it a different type of phytoplankton and the surface waters have just enough light for the algae to populate and flourish. The result is these mesmerizing patterns of turquoise and green.
This image represents one piece of much larger, incredibly complex ecosystem. While one would not normally associate the breaking up of sea ice with phytoplankton blooms, it is an intricate process of the phytoplankton life cycle. The size of the blooms have varied greatly from year to year, and experts are unsure why. Images like these can help scientists track the development of these blooms and link it to other environmental changes.
7. Hawaii’s Kilauea
Sometimes fresh lava is best viewed in infrared.
This false-color image of Kilauea, captured by OLI on Landsat 8 on May 23, 2018, shows the infrared signal emitted by lava flowing toward the sea. The purple areas surrounding the glowing lava are clouds lit from below, indicating that this image was taken through a break in the clouds.
The Puʻu ʻŌʻō Kupaianaha eruption has been continuously spewing red-hot lava since 1983, making it the longest eruption at Kilauea in recorded history. However, new fissures opened up this year that forced many to evacuate the area. Hawaii’s largest lake evaporated in hours and hundreds of homes were destroyed in Vacationland and Kapoho.
Imagery, seismometers and ground-based instruments were used to track the underground movement of magma. Infrared imagery can be incredibly helpful in disasters like this when you to view data that cannot be observed with the naked eye.
6. California’s Woolsey Burn Scar
Nothing quite encapsulates the destruction of a wildfire like a photo from outer space.
This image of the Woolsey Fire aftermath in Southern California was captured on Nov. 18, 2018 by the Advanced Spaceborned Thermal Emission and Reflection Radiometer (ASTER) on the Terra satellite. This false-color infrared image has been enhanced to clearly show the burned vegetation (indicated by brown) and the vegetation that survived unscathed (indicated by green).
The Woolsey Fire clearly left its mark, with almost 152 square miles (394 square km) and 88% of the Santa Monica Mountains National Recreation Area badly burned. Images like this one can assist fire managers in the area plan for recovery.
5. Bangladesh’s Padma River
As the years go by, the Padma River grows and shrinks, twists and turns. It never has a fixed shape, and as a result, thousands of people must regularly adapt to the constant changes in the river’s 75-mile (130-km) shoreline.
This image captured on Jan. 20, 2018 by OLI on Landsat 8 depicts one of the major rivers of Bangladesh. For thirty years, scientists have been tracking the erosion of the river with satellite imagery. Combinations of shortwave infrared, near infrared, and visible light are used to detect differences year-to-year in width, depth, and shape of the river. Sometimes the river splits off, but then rejoins again later. These patterns are created by the river carrying and depositing sediment, shaping the curves of the path of water.
Monitoring the Padma River is going to become especially important as a new bridge development project advances in the Char Janajat area. Although the bridge will most certainly help shorten travel times for citizens, nobody is quite sure how the river erosion might affect the construction and vice versa.
4. Alaska’s Yakutat Glacier
It’s hard to believe that Harlequin Lake was once all dry land — but it only started to form once Yakutat Glacier started melting. The lake appeared at the beginning of the twentieth century, and has been growing rapidly ever since.
In this hauntingly beautiful image, captured on Sep. 21 2018 by OLI on Landsat 8, the effect of climate change is apparent — especially when compared to earlier images of the region.
Unless the climate warming starts to reverse very soon — which scientists consider very unlikely — Yakutat could be gone as soon as 2070.
3. South Africa’s Theewaterskloof
Cape Town is a seaside city planted on the tip of South Africa. It’s a city known for its beaches and biodiversity — it also almost became known as the first major city to officially run out of water.
This image of Cape Town’s largest reservoir — Theewaterskloof — was acquired on Jul. 9th, 2018 by OLI on Landsat 8. By the time this photo was taken, the city’s main reservoirs stood at 55%. This was a huge increase from where it stood just six months earlier: just 13%.
The severe water shortage in the region started in 2015, only to become more threatening after three successive and unusually dry years. The entire city was preparing for Day Zero — the day the tap water would be shut off.
Despite forecasts that Day Zero would arrive in April, a combination of heavier rains and local conservation efforts restored the majority of the reservoir.
2. Aerosol Earth
Aerosols are all around us. From the smoke from a fire, to the dust in the wind to the salt in sea spray — these solid particles and liquid droplets are always swirling in our atmosphere, oftentimes unseen.
The Goddard Earth Observing System Forward Processing (GEOS FP) model uses mathematical equations to model what is happening in our atmosphere. The inputs for its equations — temperature, moisture, wind, etc. — come from our satellites and ground sensors.
This visualization was compiled on Aug. 24, 2018 — obviously a busy day for aerosols in our atmosphere. Swirls of sea salt (indicated by blue) reveal typhoons Soulik and Cimaron heading straight towards South Korea and Japan. A haze of black carbon (indicated by red) suffuse from agricultural burning in Africa and large wildfires in North America. And clouds of dust (indicated by purple) float off the Sahara desert.
1. Camp Fire
With nearly a hundred fatalities, hundreds of thousands of acres burned and billions of dollars of damage, the world watched in horror as Camp Fire grew to become the most destructive California wildfire in recorded history.
This image was captured on Nov. 8, 2018 by OLI on Landsat 8 on the same day Camp Fire ignited. It consolidates both visible light and shortwave-infrared light in order to highlight the active fire. Strong winds and dry conditions literally fanned the flames and spread this wildfire like a rash.
This image has not only become the iconic portrait for Camp Fire, it is also sobering representation of how quickly a fire can grow out of control in a short amount of time. Even from space, you can almost smell the massive plumes of smoke and feel the heat of the fires.
Whether you realize it or not, our Earth satellite missions are collecting data everyday in order to monitor environmental changes and prepare for natural disasters. If your interest is piqued by this list, head over to the Earth Observatory. The Earth Observatory updates daily with fresh, new content — brought to you by none other than our eyes in the sky.
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