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Earth Matters

NASA News Roundup: March 2017

March 31st, 2017 by Pola Lem

Here’s a roundup of some of the latest Earth science news from NASA.

The number of days with lethal dehydration risk rises in a future scenario where the Earth warms by 7 degrees Fahrenheit. Credit: NASA


Longer, more intense, and more frequent heatwaves threaten U.S. songbirds, according to a recent study. In a scenario where temperatures increase by 4 degrees Celsius (7 degrees Fahrenheit), five species of songbirds will become more prone to mass die-offs due to dehydration. Researchers used data from the North American Land Data Assimilation System (NLDAS) and physiological data in the study. Read more here.


This spring, scientists descended into ice caves below Mount Erebus—the entrance to the underworld, according to the ancient Greeks. Aaron Curtis, a postdoctoral scholar at NASA’s Jet Propulsion Laboratory, used the icy environment to test robots, a drill, and computer-aided mapping technology. The tests were intended to explore and simulate how these tools might perform on icy planets.  Read more here.


How thick is the Earth’s ozone layer now, after years of depletion, regulation, and recovery? The Stratospheric Aerosol and Gas Experiment (SAGE) III instrument is set to monitor “the Earth’s sunscreen,” as well as other gases and particles, from the International Space Station. Following its installation in March 2017, SAGE will keep a pulse on ozone, water vapor, and aerosols in our atmosphere.

Read more about SAGE III here and here.

Egypt’s Greening Desert

March 29th, 2017 by Kathryn Hansen

NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey.


Cultivated desert. Photo by Ragab Hafiez.

In early March 2017, we featured the top image as our monthly satellite puzzler and as an Image of the Day. But sometimes we learn even more about an image after we publish, as people write to us with a local or personal connection to the place. That was the case here.

Local knowledge is especially important when it comes to agriculture. Ragab Hafiez, a hydrogeologist and geologist working for DASCO, studies Egypt’s Western Desert. He gave us permission to re-publish some of his photographs showing the ground-based view of East Owinat, one of Egypt’s land reclamation projects aimed at making some desert areas suitable for agriculture. He also took the time to answer some questions about the satellite image that inspired the puzzler.

Q: What features visible in these images strike you as interesting?

A: The features visible in these images are the irrigated crops mainly clustered in a center-pivot irrigation systems; the diameter of the pivots range from 700 to 820 meters. The total irrigated area at the beginning of this year was about 79,000 hectares.

Q: Is there anything not visible that is worth noting?

A: East Owinat is an interesting area located at the far south of Egypt. It’s an arid to hyper-arid area, the rainfall is nil, and fossil groundwater is the only source of water in the area.

The area is covered with a thin sheet of loose sand, followed by the thick sandstone rock bed. The sandstone beds belong to the Nubian sandstone formation deposited through the Lower Cretaceous and Jurassic periods.

The water wells in the area are usually drilled to depths of 200 to 350 meters (650 to 1150 feet) below the ground surface. The water level ranged from 30 to 60 meters (100 to 200 feet) below ground.

Q: Do you happen to know what crops are planted here, and the reason for the various green/brown patters?

A: The crops cultivated in the winter season are wheat, barley, potatoes, and alfalfa. Virgin soil, fresh water (salinity less than 700 parts per million), mild weather, and long daily sunlight hours are all factors that combine to produce high-quality and prolific crops.

The green areas are currently cultivated, while the brown areas are left without cultivation this season.

Wheat fields. Photo by Ragab Hafiez.


Potato fields in the desert. Photo by Ragab Hafiez.


Most NASA stories about sea ice records tend to start with the year 1979, when consistent observations started to be collected regularly by satellites. But we do know a bit about what happened before then based on aerial, ocean, and ground-based data. And now some recently recovered observations and new modeling suggest that Arctic sea ice grew for a period between 1950 and 1975.

The Sun hangs low on the horizon above solidified pancake ice in the Arctic Ocean. (Photograph courtesy Andy Mahoney, NSIDC.)

A new analysis led by Marie-Ève Gagné of Environment and Climate Change Canada offers an explanation for the rise: air pollution. Gagné and colleagues showed that sulfate aerosol particles, which are released by the burning of fossil fuels, may have disguised the impact of greenhouse gases on Arctic sea ice.

In a press release, the American Geophysical Union explained more details:

These particles, called sulfate aerosols, reflect sunlight back into space and cool the surface. This cooling effect may have disguised the influence of global warming on Arctic sea ice and may have resulted in sea ice growth recorded by Russian aerial surveys in the region from 1950 through 1975, according to the new research.

“The cooling impact from increasing aerosols more than masked the warming impact from increasing greenhouse gases,” said John Fyfe, a senior scientist at Environment and Climate Change Canada and a co-author of the new study accepted for publication in Geophysical Research Letters.

To test the aerosol idea, researchers used computer modeling to simulate sulfate aerosols in the Arctic from 1950 through 1975. Concentrations of sulfate aerosols were especially high during these years before regulations like the Clean Air Act limited sulfur dioxide emissions that produce sulfate aerosols.

The study’s authors then matched the sulfate aerosol simulations to Russian observational data that suggested a substantial amount of sea ice growth during those years in the eastern Arctic. The resulting simulations show the cooling contribution of aerosols offset the ongoing warming effect of increasing greenhouse gases over the mid-twentieth century in that part of the Arctic. This would explain the expansion of the Arctic sea ice cover in those years, according to the new study.

Aerosols spend only days or weeks in the atmosphere so their effects are short-lived. The weak aerosol cooling effect diminished after 1980, following the enactment of clean air regulations. In the absence of this cooling effect, the warming effect of long-lived greenhouse gases like carbon dioxide has prevailed, leading to Arctic sea ice loss, according to the study’s authors.

Read more about aerosols and sea ice.

This chart, from Gagné et al, shows the area-averaged annual mean sea ice concentration anomaly between 1950 and 2005. The red line reflects Arctic and Antarctic Research Institute (AARI) data, which is based on historical sea ice charts from several sources (aircraft, ship, and satellite observations). The blue Walsh & Chapman data includes additional historical sources and uses slightly different techniques for merging various data streams. The black line is a simulated mean sea ice concentration from the CanESM2 large ensemble, a group of models developed at the Canadian Center for Climate Modelling and Analysis. Anomalies are relative to climatological averages between 1975 and 2005. The time series have been lightly smoothed with 5-year running mean. The gray shading shows the 5-95 percent range over the individual simulations of the model ensemble. The dotted lines are the piecewise linear approximated trends.

Thank You, GRACE

March 23rd, 2017 by Adam Voiland

On March 17, 2002, two small satellites (nicknamed Tom and Jerry) blasted off from the Plesetsk Cosmodrome in northern Russia. In the 15 years since, there is nothing funny about what this pair has accomplished. In fact, as my colleague Carol Rasmussen noted, revolutionary is more often the word used when scientists describe the Gravity Recovery and Climate Experiment (GRACE).

By measuring Earth’s gravity field, the satellites have pioneered a whole new way of monitoring water. The details of what this pair has observed has been eye-opening. Among the most sobering of GRACE’s many discoveries:

In cat years, Tom and Jerry are nearing 75. To celebrate their longevity, give a read of this excellent overview story written by Holli Riebeek of the Earth Observatory and this list of all the GRACE press announcements from the Jet Propulsion Laboratory. Below are a few of my favorite videos and data visualizations about the mission.

The American Museum of Natural History video offers a quick overview. The State Department video is longer and wonkier, but has some really interesting details. And the 60 Minutes clip (part of this longer episode) is a reminder that NASA studies earth science in a way that few other organizations can. Click on each of the maps below to find out more about them.

Basins shown in shades of brown have had more water extracted than could be naturally replenished.

NASA Earth Observatory images by Joshua Stevens using GRACE global groundwater data courtesy of Jay Famiglietti NASA JPL/University of California Irvine and Richey et al. (2015).


The freshwater storage rate in the United States changed between 2003-2012. Red areas stored less groundwater during that period.

NASA Earth Observatory image by Jesse Allen, using GRACE data provide courtesy of Jay Famigleitti, University of California Irvine and Matthew Rodell, NASA GSFC, and Famiglietti & Rodell (2013).

Water masses move around the planet throughout the year. Blues indicate increases above the normal water storage for an area. Browns indicate decreases.

NASA maps by Robert Simmon, using GRACE data.

Green Ice and Snow

March 21st, 2017 by Kathryn Hansen

You never know where phytoplankton will turn up next. From space, we regularly see colorful blooms of them swirling in the world’s oceans. Inland basins and waterways support them too, such as Florida’s Lake Okeechobee, Washington’s Hood Canal, and North America’s Great Lakes.

Even the waters off the coast of Antarctica can sustain blooms. We recently showed a satellite image in which algae in a harbor near the Ross Sea had turned the sea ice a wild shade of green. As this photograph shows, they also appear to thrive on the snow and ice capping the southern continent.

“I was in Antarctica in February 2013 and saw plenty of algae happily growing in the ice (green, yellow, and red),” said ocean scientist Norman Kuring of NASA’s Goddard Space Flight Center. “I took this photo on Orne Island showing lots of green snow and ice.”

Kuring notes, however, that the type of phytoplankton inhabiting the snow and ice on Orne Island — on the opposite side of the continent, near the Antarctic Peninsula — is probably different from the species that bloomed in the Ross Sea. Direct sampling and analysis is the best way to know for sure, but that’s not always possible, especially in remote regions.

Video Roundup: Snow, Snow Everywhere

March 16th, 2017 by Pola Lem

Editor’s note: Here’s a roundup of the latest eye-catching earth science videos from NASA and beyond. In March, snow emerged as a theme.

Where there is snow, there is water. Scientists trudged through thick white powder in Grand Mesa and the Senator Beck Basin to measure the depth of snow and its water content for the SnowEx campaign.


A scientist with the Global Precipitation Measurement (GPM) mission explains why snowflakes look the way they do.


Did you know that 60 million Americans rely on snowmelt as their main source of water?

And if you’re not completely buried in white stuff, check out a National Geographic short documentary on a Colorado man who has been taking daily snow measurements for decades.


Photon Jump” tells the story of an exuberant photon. Follow this miniature light particle as s/he is spat out of a satellite sensor in Earth’s orbit. A team of students at Georgia’s Savannah College of Art and Design (SCAD) created the film for the upcoming ICESat-2 mission, which will measure snow and ice on Earth.



Blizzard 2017: Not In Denver, but in Hawaii

March 10th, 2017 by Pola Lem

In Hawaii, land of palm trees, pineapples, and year-round surfing, a full-blown blizzard hit last week. The early March storm brought more than 8 inches (20 centimeters) to the top of Mauna Kea volcano, leading authorities to shut the road to the peak.

The snow was all the more surprising given how little has fallen in more traditionally snowy locales. Hawaii received more snow that day than Denver has accumulated over the past seven weeks. The Colorado city got 1.6 inches (4 centimeters) in the past 51 days, according to local news.

The island archipelago also got more white stuff than Chicago. That city, famed for its bitter winters, is currently in the midst of a snow drought, with a mere 0.6 inches (1.5 centimeters) falling in 2017. That’s the least on record since the late 1800s. To put that into perspective: Chicago averages 37 inches (94 cm) of yearly snowfall. By contrast, Hawaii gets a yearly average of 3.7 inches (9 cm).

Thanks to their height, the peaks of Mauna Kea and Mauna Loa volcanoes do receive a dusting now and again. But that snow rarely sticks around for more than a few days, according to Ken Rubin, an assistant professor of geology and geophysics at the University of Hawaii.

Mauna Kea in December 2016. Image: NASA Earth Observatory/Jesse Allen, using Landsat data from the U.S. Geological Survey.


The Surreal Beauty of Lightning Seen from Space

March 9th, 2017 by Adam Voiland

If you’re like me, you’ll find yourself transfixed by this newly released clip of lightning flashes flitting across Texas skies at night. These data were captured by the Geostationary Lightning Mapper (GLM), a first-of-its-kind sensor that was launched into space on GOES-16 (called GOES-R prior to launch) in November 2016. The sensor makes continuous observations of lightning flashes—a new capability that should markedly improve weather forecasts of severe thunderstorms and tornadoes.

The video clip—an animation of GLM observations overlaid on Advanced Baseline Imager (ABI) cloud imagery—shows lightning flashing over southeast Texas on the morning of February 14, 2017. As explained by NOAA’s Michelle Smith, the green cross indicates the location of Houston, and the green dotted lines show the Texas coastline. Rendered at 25 frames per second, the animation simulates what your eye might see if it was above the clouds. GLM observes the scene at 500 frames per second, and can distinguish the location, intensity, and horizontal propagation of individual strokes within each lightning flash.

March Puzzler

March 8th, 2017 by Kathryn Hansen

Every month on Earth Matters, we offer a puzzling satellite image. The March 2017 puzzler is above. Your challenge is to use the comments section to tell us what part of the world we are looking at, when the image was acquired, what the image shows, and why the scene is interesting.

How to answer. Your answer can be a few words or several paragraphs. (Try to keep it shorter than 200 words). You might simply tell us what part of the world an image shows. Or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure speck in the far corner of an image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t offer prize money or a trip to Mars, but we can promise you credit and glory. Well, maybe just credit. Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. After we post the answer, we will acknowledge the person who was first to correctly ID the image at the bottom of this blog post. We may also recognize certain readers who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have played a role in molding the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you want us to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the last few months or work in geospatial imaging, please sit on your hands for at least a day to give others a chance to play.

Releasing Comments. Savvy readers have solved some of our puzzlers after only a few minutes or hours. To give more people a chance to play, we may wait between 24-48 hours before posting the answers we receive in the comment thread.

Good luck!

Editor’s Note: Congratulations to Italo Moletto-Lobos, Mark D, Peter Upshall, and Avinash Wagh for being the first readers to solve the puzzler on Earth Matters and Facebook. Special mention goes to Mark D and James Varghese for their thorough explanations. See a labeled version of the March puzzler with a detailed description of central-pivot irrigation in Egypt’s Western Desert here.

Is That The Best You Can Do?

March 2nd, 2017 by jallen

Regular readers of our site may have noticed our recent piece on the Antarctic Peninsula. That Aqua MODIS shot was made possible by a weather pattern that brings clearer skies to the peninsula in January or February most years. You can see the same pattern in finer detail with a mosaic of Landsat scenes from early 2016.

But that was last year: what are things like this year?

Here’s the best shot of the peninsula this year during the “clear skies” season. It comes from the Aqua MODIS instrument and was acquired on February 7, 2017.

You can quickly see that it is not as clear as the best view from early 2016. The western side of the Peninsula and its neighboring islands are clouded in. On the other side, there’s a clearer edge to the eastern ice shelves because the wind has been blowing the loose sea ice in the Weddell Sea away from the coast, leaving a narrow gap of open water along the edges of the shelves. The distinction between the Larsen C and D shelves and the sea ice is much more clear than it was last year.

In a closer view, you can also see the crack in the Larsen C ice shelf.  In August 2016, the crack extended from the Gipps Ice Rise northward for 130 kilometers (80 miles), and the crack has continued to grow since.