Earth Observation Archives

August 17, 2011December 24, 2015 by Nancy Atkinson

Explosive Phytoplankton Bloom Seen From Space

Phytoplankton bloom in the Barents Sea. Credit: NASA/Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite

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Phytoplankton are tiny, microscopic plant-like organisms, but when they get together and start growing they can cover hundreds of square kilometers and be easily visible in satellite images. This image of the Barents Sea was taken on August 14, 2011 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite. When conditions are right, phytoplankton populations can grow explosively, a phenomenon known as a bloom. A bloom may last several weeks, but the life span of any individual phytoplankton is rarely more than a few days. The area in this image is immediately north of the Scandinavian peninsula. Blooms spanning hundreds or even thousands of kilometers occur across the North Atlantic and Arctic Oceans every year. But, said Jeff Schmaltz from NASA’s Earth Observatory website, seeing such a wide area without clouds during the bloom is a rare treat.

Phytoplankton thrive in cold ocean waters, which tend to be rich in nutrients. Schmaltz said the milky blue color is an indicator that the bloom probably contains coccolithophores, which are plated with white calcium carbonate. Seen through ocean water, a coccolithophore bloom is bright blue. Other shades may be from other species of phytoplankton.

Source: NASA’s Earth Observatory website

July 26, 2011April 26, 2016 by Jason Major

Manhattan-Sized Ice Island Seen From Space

An iceberg the size of Manhattan drifts off the coast of Labrador

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Taken by NASA astronaut and Expedition 27 flight engineer Ron Garan, this image shows the Petermann Ice Island (PII-A) currently adrift off the coast of Labrador. The island is a chunk of ice that broke off the Petermann Glacier in Greenland in August of 2010 and has been moving slowly southward ever since. It is currently about 21 square miles (55 square km) in size – nearly the same area as Manhattan!

Garan’s original photo was posted to his Twitter feed earlier today… I cropped the full-size version, rotated it so that south is down and edited it to bring out surface details in the island. Ridges in its surface can be seen as well as many bright blue meltwater ponds.

356413805 — "Another look at that lonely iceberg from space... can you find it?" @Astro_Ron

Overlaid on the left side is an approximate scale size of Manhattan. This thing is BIG!

PII-A is currently drifting toward Newfoundland but is unlikely to reach land… its base will run against the sea floor long before that. But it has been reported to be posing a problem for ships and offshore oil rigs. (Read more about PII-A on NASA’s Earth Observatory site here.)

When he’s not performing other duties aboard the Space Station, Ron Garan posts photos of Earth from orbit on his Twitter feed (@Astro_Ron) and also on his website FragileOasis.org, thereby sharing his unique and privileged perspective on our world. Founded by Garan, Fragile Oasis is a site that supports and publicizes many global projects supporting humanitarian and environmental missions. Visit, become a member, and you too can “learn, act, and make a difference.” After all, who better than an astronaut would know how much our world is connected, and how fragile it really is!

Image credit: NASA / Ron Garan. Edited by Jason Major.

PS: If you want an idea of how something like this would look like up close, check out this video below taken from a ship near one of the smaller pieces of the ice island!

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Jason Major is a graphic designer, photo enthusiast and space blogger. Visit his website Lights in the Dark and follow him on Twitter @JPMajor or on Facebook for the most up-to-date astronomy awesomeness!

June 27, 2011December 24, 2015 by Nancy Atkinson

Satellite Looks Down the Eye of Erupting Nabro Volcano

This false color satellite image shows active lava flows of the Nabro volcano in Eritrea on June 24, 2011. Credit: the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite.

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Wow! What an amazing and detailed top-down view of an active volcano! This is the Nabro Volcano, which has been erupting since June 12, 2011. It sits in an isolated region on the border between Eritrea and Ethiopia and satellite remote sensing is currently the only reliable way to monitor the ongoing eruption, according to the NASA Earth Observatory website. The bright red portions of the false-color image (above) indicate hot surfaces. See below for a zoomed-in look. Both images were taken by the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite.

This natural-color image shows a close-up view of the volcanic plume and eruption site of the Nabro volcano. Credit: the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite. — This natural-color image shows a close-up view of the volcanic plume and eruption site of the Nabro volcano. Credit: the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite

Robert Simmon of the NASA Earth Observatory website describes the scenes:

Hot volcanic ash glows above the vent, located in the center of Nabro’s caldera. To the west of the vent, portions of an active lava flow (particularly the front of the flow) are also hot. The speckled pattern on upstream portions of the flow are likely due to the cool, hardened crust splitting and exposing fluid lava as the flow advances. The bulbous blue-white cloud near the vent is likely composed largely of escaping water vapor that condensed as the plume rose and cooled. The whispy, cyan clouds above the lava flow are evidence of degassing from the lava.

The natural-color image (lower) shows a close-up view of the volcanic plume and eruption site. A dark ash plume rises directly above the vent, and a short, inactive (cool) lava flow partially fills the crater to the north. A gas plume, rich in water and sulfur dioxide (which contributes a blue tint to the edges of the plume) obscures the upper reaches of the active lava flow. Black ash covers the landscape south and west of Nabro.

Limited reports from the region say that at least 3,500 people and up to 9,000 that have been affected by the eruption, with at least 7 deaths caused by the erupting volcano. The ash plume has also disrupted flights in the region.

For more information see NASA’s Earth Observatory website, and BigThink

May 23, 2011January 18, 2016 by Nancy Atkinson

The View from 100,000 Feet

I love these student projects that send a camera via a balloon high in the atmosphere to film the view of Earth below. Here’s another from a group of German students who were able to film in HD from an altitude of more than 100,000 ft. (30,480 meters). Enjoy the music, too.

“Our challenge was to survive ambient air pressures as low as 1/100th of an atmosphere, temperatures as low as -60°C and finally to locate and recover the Camera,” Tobias Lohf wrote UT. “We had a HD-Cam, GPS tracker and a heating pad on board, and all the construction had a total weight of about 1kg.”

The rest of the team included Marcel Dierig, Tobias Stodieck, Tristan Eggers and Marvin Rissiek and they hope to inspire other students to try the same project. “All you need need is a camera, weather balloon and Duct Tape,” they said.

May 17, 2011December 24, 2015 by Nancy Atkinson

New Satellite Will ‘Taste’ Earth’s Salty Seas from Orbit

Artist's concept of the Aquarius/SAC-D spacecraft, a collaboration between NASA and Argentina's space agency, with participation from Brazil, Canada, France and Italy. Aquarius, the NASA-built primary instrument on the spacecraft, will take NASA's first space-based measurements of ocean surface salinity, a key missing variable in satellite observations of Earth that links ocean circulation, the global balance of freshwater and climate. The mission is scheduled to launch in June. Image credit: NASA

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From a JPL press release:

Final preparations are under way for the June 9 launch of the international Aquarius/SAC-D observatory. The mission’s primary instrument, Aquarius, will study interactions between ocean circulation, the water cycle and climate by measuring ocean surface salinity.

Engineers at Vandenberg Air Force Base in California are performing final tests before mating Aquarius/SAC-D to its Delta II rocket. The mission is a collaboration between NASA and Argentina’s space agency, Comision Nacional de Actividades Espaciales (CONAE), with participation from Brazil, Canada, France and Italy. SAC stands for Satelite de Applicaciones Cientificas. Aquarius was built by NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and the agency’s Goddard Space Flight Center in Greenbelt, Md.

In addition to Aquarius, the observatory carries seven other instruments that will collect environmental data for a wide range of applications, including studies of natural hazards, air quality, land processes and epidemiology.

The mission will make NASA’s first space observations of the concentration of dissolved salt at the ocean surface. Aquarius’ observations will reveal how salinity variations influence ocean circulation, trace the path of freshwater around our planet, and help drive Earth’s climate. The ocean surface constantly exchanges water and heat with Earth’s atmosphere. Approximately 80 percent of the global water cycle that moves freshwater from the ocean to the atmosphere to the land and back to the ocean happens over the ocean.

Salinity plays a key role in these exchanges. By tracking changes in ocean surface salinity, Aquarius will monitor variations in the water cycle caused by evaporation and precipitation over the ocean, river runoff, and the freezing and melting of sea ice.

Salinity also makes seawater denser, causing it to sink, where it becomes part of deep, interconnected ocean currents. This deep ocean “conveyor belt” moves water masses and heat from the tropics to the polar regions, helping to regulate Earth’s climate.

“Salinity is the glue that bonds two major components of Earth’s complex climate system: ocean circulation and the global water cycle,” said Aquarius Principal Investigator Gary Lagerloef of Earth & Space Research in Seattle. “Aquarius will map global variations in salinity in unprecedented detail, leading to new discoveries that will improve our ability to predict future climate.”

Aquarius will measure salinity by sensing microwave emissions from the water’s surface with a radiometer instrument. These emissions can be used to indicate the saltiness of the surface water, after accounting for other environmental factors. Salinity levels in the open ocean vary by only about five parts per thousand, and small changes are important. Aquarius uses advanced technologies to detect changes in salinity as small as about two parts per 10,000, equivalent to a pinch (about one-eighth of a teaspoon) of salt in a gallon of water.

Aquarius will map the entire open ocean every seven days for at least three years from 408 miles (657 kilometers) above Earth. Its measurements will produce monthly estimates of ocean surface salinity with a spatial resolution of 93 miles (150 kilometers). The data will reveal how salinity changes over time and from one part of the ocean to another.

The Aquarius/SAC-D mission continues NASA and CONAE’s 17-year partnership. NASA provided launch vehicles and operations for three SAC satellite missions and science instruments for two.

JPL will manage Aquarius through its commissioning phase and archive mission data. Goddard will manage Aquarius mission operations and process science data. NASA’s Launch Services Program at the agency’s Kennedy Space Center in Florida is managing the launch.

CONAE is providing the SAC-D spacecraft, an optical camera, a thermal camera in collaboration with Canada, a microwave radiometer,; sensors from various Argentine institutions and the mission operations center there. France and Italy are contributing instruments.

See the Aquarius/SAC-D website for more information. , visit:

May 13, 2011December 24, 2015 by Nancy Atkinson

Mississippi River Flooding As Seen from the Space Station

Flood water from the Mississippi river near New Madrid, Missouri, as seen by Paolo Nespoli on board the International Space Station. Credit:ESA/NASA

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Big Muddy, as the Mississippi River is known, looks especially big and muddy these days with record flooding occurring along the largest river in the US. The Mississippi has risen to levels not seen in since the 1920’s and 30’s, fed by heavy spring rains and the spring thaw from heavy snows in the northern US this winter. Here are some new images taken by International Space Station astronaut Paolo Nespoli, which show surprising detail of how the river has spread across farmland and through cities and towns. The image above shows the area around New Madrid, Missouri, along the border of Kentucky.

Flooding near Ridgely, Tennessee. Credit: ESA/NASA

In this image, levees are visible which are containing the flood near Ridgely, Tennessee.

Here, flooded areas from the Mississippi is about 5 miles wide. Credit: ESA/NASA

Flooding near Caruthersville, Missouri. Farmland, roads and bridges are under water. Credit: ESA/NASA

Last week, the US Army Corps of Engineers opened floodways in Missouri to keep pressure off levees protecting the town of Cairo, Illinois, flooding thousands of acres of farmland. This week, the Corp is preparing to flood up to three million acres in southern Louisiana in hopes of protecting large cities along the Mississippi River such as Baton Rouge and New Orleans, Louisiana. More than 25,000 people are preparing to leave the region before the spillways would be opened.

See more images from Nespoli on his Flickr page.

May 2, 2011December 24, 2015 by Nancy Atkinson

Satellite Imagery Shows How Tornadoes Slashed Across Alabama, Mississippi

This image shows the path of exposed ground left in the wake of an EF5 tornado in Mississippi. Credit: MODIS Rapid Response Team at NASA GSFC.

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Some extraordinary satellite and radar imagery shows how the deadly tornado supercell slashed through Alabama and Mississippi last week, as in the image above, leaving a gash of exposed ground and destruction that is visible from space. The latest reports indicate fatalities from the outbreak now exceed 342 people, and according to the Washington Post, this is the most people killed by tornadoes in a two-day period since April 5-6, 1936 when 454 people died. The image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on April 28. See more imagery below.

Part of the path of a 12-mile swath of destruction in Alabama from an EF4 tornado on April 27. Click to see the entire swath taken by a NOAA satellite. Credit: NOAA

The National Weather Service said an EF4, with winds around 175 miles per hour, created a 12-mile-long track of destruction. This tornado caused more than 20 deaths.

Radar sequence of tornado supercell thunderstorms that tracked from western Mississippi into southwest North Carolina. Credit: NCAR, Brian Tang.

This image is pretty amazing: it is a radar montage of the supercell showing some of the 150 tornadoes that were reported on April 27 and 28, 2011. This cell traveled about 450 miles and lasted over 8 hours.

This animation from the NASA Earth Observatory team starts on April 26 and runs through the morning of April 28. It shows a relatively stable mass of cold air—visible as a swirl of more-or-less continuous clouds—rotates in the north along the top of the image, and meanwhile, moist air pushes north and west from the Atlantic Ocean and Gulf of Mexico. The two air masses collide and generate severe weather, but the bad weather also was amplified by the jet stream on April 27, which helped generate the lines of intense thunderstorms and tornadoes.

Sources: NASA Earth Observatory, Washington Post, NOAA

April 28, 2011December 24, 2015 by Nancy Atkinson

Satellite Captures 3-D View of Violent Storms that Ravaged the US on April 27-28

The Tropical Rainfall Measuring Mission satellite captured the rainfall rates occurring in the line of thunderstorms associated with a powerful cold front moving through the eastern U.S. on April 28, 2011. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. The very small red areas are heavy rainfall at almost 2 inches (50 mm) per hour. Credit: NASA/SSAI, Hal Pierce

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NASA’s Tropical Rainfall Measuring Mission (TRMM) satellite captured 3-D images of severe thunderstorms that were spawning tornadoes over the eastern United States on April 28, detecting massive thunderstorms and very heavy rainfall. Tornadoes associated with this extremely unstable weather left at least 202 dead across the Eastern U.S, with injuries numbering over a thousand.

TRMM flew over the strong cold front and captured data at 0652 UTC (2:52 AM EDT) on April 28, 2011. Most of the rainfall was occurring at moderate rates however, there were pockets of very heavy rainfall in Virginia, North Carolina, South Carolina, Georgia and Alabama where rain was falling at a rate of 2 inches (50 millimeters) per hour.

This TRMM radar vertical cross section shows that some of these violent storms reached to incredible heights of almost 17 km (~10.6 miles). Credit: NASA/SSAI, Hal Pierce

In the image above and the lead animation, TRMM data was used to generate a 3-D look at the storm. TRMM’s Precipitation Radar (PR) data was used by Hal Pierce of SSAI at NASA’s Goddard Space Flight Center in Greenbelt, Md. to create a 3-D structure of those storms. The image Pierce created is a TRMM radar vertical cross section that shows some of these violent storms reached to incredible heights of almost 17 km (~10.6 miles).

TRMM, is the Energizer Bunny of satellites as it keeps going and going. It was launched in 1997 and was scheduled at one time to be decommissioned in 2004. But its systems keep operating and it is has been able to keep gathering useful information on storms and climate. It now has operated well over a decade past its original life expectancy.

TRMM is managed by both NASA and the Japanese Space Agency.

Source: NASA

April 6, 2011December 24, 2015 by Nancy Atkinson

Arctic Ozone Levels Reach All-Time Low

This set of images by the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite shows March 19, 2010 on the left, and the right shows the same date in 2011. March 2010 had relatively high ozone, while March 2011 has low levels. NASA image by Rob Simmon, with data courtesy of Ozone Hole Watch.

In the past, massive ozone loss over Antarctica has grabbed the headlines. But this year, measurements by several different sources show record levels of stratospheric ozone loss over the Arctic. Scientists say the main reason for the record ozone loss this year is that unusually cold stratospheric temperatures, which have endured later into the season than usual. Scientists say the unusual loss is not catastrophic, but something that needs to be monitored.

The World Meteorological Organization cautioned that people who live in northerly latitudes could get sunburned easier, noting that ozone-depleted air masses extended from the north pole to southern Scandinavia.

The record low temperatures were caused by unusually strong winds, known as the polar vortex, which isolated the atmospheric mass over the North Pole and prevented it from mixing with air in the mid-latitudes.

This has allowed for the formation of polar stratospheric clouds, and the catalytic chemical destruction of ozone molecules occurs on the surface of these clouds which form at 18-25 kilometers height when temperatures drop below -78 C.

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This created conditions similar to those that occur every southern hemisphere winter over the Antarctic.
Measurements by ESA’s Envisat satellite, the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite, and France’s MetOp satellite, as well as observations made since January from the ground and from balloons show all show that 40% of ozone molecules have been destroyed over the Arctic.

Ozone is a protective atmospheric layer found at around 25 km altitude that acts as a sunlight filter shielding life on Earth from harmful ultraviolet rays, which can increase the risk of skin cancer and cataracts in humans and harm marine life.

Stratospheric temperatures in the Arctic usually do vary widely from winter to winter. Last year, temperatures and ozone above the Arctic were very high. The last unusually low stratospheric temperatures over the North Pole were recorded in 1997.

See this link from ESA that shows a animation comparison between 2010 and 2011.

“This depletion is not necessarily a big surprise,” said Paul Newman, an atmospheric scientist and ozone expert at NASA’s Goddard Space Flight Center. “The ozone layer remains vulnerable to large depletions because total stratospheric chlorine levels are still high, in spite of the regulation of ozone-depleting substances by the Montreal Protocol. Chlorine levels are declining slowly because ozone-depleting substances have extremely long lifetimes.”

Ozone “holes” do not form consistently over the North Pole like they do in Antarctica. “Last winter, we had very high lower stratospheric temperatures and ozone levels were very high; this year is just the opposite,” Newman said. “The real question is: Why is this year so dynamically quiet and cold in the stratosphere? That’s a big question with no good answer.”

Scientists will be watching in coming months for possible increases in the intensity of ultraviolet radiation (UV) in the Arctic and mid-latitudes, since ozone is Earth’s natural sunscreen. “We need to wait and see if this will actually happen,” Newman said. “It’s something to look at but it is not catastrophic.”

Scientists are also investigating why the 2011 and 1997 Arctic winters were so cold and whether these random events are statistically linked to global climate change. “In a changing climate, it is expected that on average stratospheric temperatures cool, which means more chemical ozone depletion will occur,” said Mark Weber from the University of Bremen.

Experts say that on a global scale, the ozone layer is still on a long-term course for recovery. But for decades to come, there remains a risk of major ozone losses on yearly or regional scales.

Sources: Nature, ESA, NASA, The Independant Science Daily Earth/Sky Blog

March 31, 2011December 24, 2015 by Nancy Atkinson

New Results from GOCE: Earth is a Rotating Potato

In this GOCE image, gravity is strongest in yellow areas; it is weakest in blue ones. Credit: ESA

Although they aren’t particularly fond of the comparison, scientists from the GOCE satellite team had to admit that new data showing Earth’s gravity field – or geoid — makes our planet look like a rotating potato. After just two years in orbit, ESA’s sleek and sexy GOCE satellite (Gravity Field and Steady-State Ocean Circulation Explorer) has gathered sufficient data to map Earth’s gravity with unrivalled precision. While our world certainly doesn’t look like a spinning tuber, this exaggerated view shows the most accurate model of how gravity varies across the planet.

The geoid is nothing more than how the oceans would vary if there were no other forces besides gravity acting on our planet.

“If we had an homogeneous sphere, it would be a boring sphere,” said GOCE scientist Roland Pail from Technical University in Munich, speaking at the press briefing today. “But due to rotation, you get a flattening of the Earth, and we have topography such as mountains, and irregular mass distribution in Earth’s interior. What we are showing you here, in principle, is the gravity field by any deviations due to inhomogeneous mass distributions on the Earth and the Earth’s interior.”

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While a previous gravity satellite, the Gravity Recovery And Climate Experiment (GRACE) operated for 8 years, most of the new data from GOCE was gathered in about 14 months, and provides data where there was none before.

GOCE is able to sense tiny variations in the pull of gravity over Earth, and the data is used to construct an idealized surface, which traces gravity lumps and bumps, and is the shape the oceans would take without winds, currents, Earth’s rotation and other forces.

By comparing sea level and geoid data, GOCE is revealing data on ocean currents and circulation, sea-level change, ice dynamics, said Rory Bingham, from the University of Newcastle, which helps understand heat transport and the changing climate.

But also of interest is how GOCE data reveals shifting tectonic plates in earthquakes and magma movements under volcanoes. Following the earthquakes in Japan, scientists are looking closely, as the data should reveal a three-dimensional view of what was going on inside the Earth. Even though the motion cannot be observed directly from space, earthquakes create signatures in gravity data, which could be used to understand the processes leading to these natural disasters and ultimately help to predict them.

“Even though these quakes resulted from big movements in the Earth, at the altitude of the satellite the signals are very small. But we should still seem them in the data,” said Dr. Johannes Bouman from the German Geodetic Research Institute.

“GOCE will give us dynamic topography and circulation patterns of the oceans with unprecedented quality and resolution,” said professor Reiner Rummel, former Head of the Institute for Astronomical and Physical Geodesy at the Technische Universität München. “I am confident that these results will help improve our understanding of the dynamics of world oceans.”

“You could say that, at its early conception, GOCE was more like science fiction,” said Volker Liebig, Director of ESA’s Earth Observation Program. “GOCE has now clearly demonstrated that it is a state-of-the-art mission.”

Sources: GOCE press briefing, ESA press release