Up Close with the Plume in the Strait of Georgia

January 12th, 2015 by Kathryn Hansen

Last week, an Earth Observatory Image of the Day featured a sediment plume from the Fraser River where it enters the Strait of Georgia. That photograph was taken by an astronaut on the International Space Station on September 6, 2014. After we posted the image on Facebook, researcher Ed Wiebe responded by sharing some close-up views of the plume.

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The photo above was taken by Kevin Bartlett of Ocean Networks Canada on May 4, 2013, from the deck of the Canadian Coast Guard research ship John P. Tully during an expedition in the Strait. According to Bartlett, the photo was taken during operations with a remotely operated vehicle (ROV), so the location would have been over the central or east node of the VENUS undersea network.

front between Fraser River water and Straight of Georgia water

Wiebe, who works at the University of Victoria, shot the second photo from the deck of a ferry in May 2007. According to Wiebe’s Facebook post: “The spring flood brings very intense loading of the surface water with sharp boundaries. The ferry between Vancouver Island and Vancouver crosses this boundary, providing a great opportunity to observe the river outflow floating on top of the saline water in the Strait of Georgia.”

Thanks to Ed and Kevin for sharing these terrific images!

The Hottest Volcano of Them All

January 9th, 2015 by Adam Voiland

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What is the hottest volcano of them all? It depends on how you define “hottest,” but a fascinating new analysis crunches the numbers in a few different ways, using satellite observations of 95 of Earth’s most active volcanoes since 2000.

In terms of total energy radiated, the prize goes to Hawaii’s Kilauea (shown above), which has been spilling lava continuously throughout the study period.  Thanks to its lava lake, Nyiragongo (Democratic Republic of Congo) came in a close second.  Africa’s most active volcano — and Nyiragongo’s neighbor — Nyamuragira came in third for overall energy radiated. For a full ranking of all 95 volcanoes, see the chart at the bottom of the bottom of this page.

Note that the volcanoes emitting the most heat do not necessarily emit it explosively. In fact, most of the top heat producers were shield volcanoes that released mafic lava slowly.

If you ignore the steady, continuous heat produced by volcanoes and look simply at the “extra” heat produced during eruptions, then the rankings look different. Iceland’s ongoing Holuhraun eruption has radiated the most heat for an event. At the time that the study was published, Holuhraun had radiated about one-third more thermal energy than the 2012-2013 eruption of Russia’s Tolbachik, which itself radiated about 50 percent more energy than the 2011-2012 eruption of Nyamuragira.

The study, led by Robert Wright of the Hawaii Institute of Geophysics and Planetology, was based on data acquired by the Moderate Resolution Imaging Spectroradiometers on NASA’s Aqua and Terra satellites. 

 

The Answers Are Still Blowing in from Wind

January 7th, 2015 by Mike Carlowicz

It’s human nature to get excited by novelty in science…to gravitate to the sexy headlines and the tales of new discoveries and the flashy imagery. But so much of science is a slow slog, an anonymous labor in ordinary looking labs and cinderblock office buildings. Most scientists know that the fundamental advances do not often come in “Eureka!” moments or get announced at press conferences. They get made in the background by the unsung worker bees, both human and technological.

And so it is for NASA’s Wind spacecraft. You probably have never heard of it. Most of my colleagues around NASA have never heard of it. And yet it has quietly made fundamental contributions to our understanding of the electric space around Earth.

wind-full

Wind studies a dark and mostly desolate netherworld between Earth and the Sun, a region that doesn’t quite fit into solar science (heliophysics) nor does it have a home in Earth science. The Wind spacecraft has no cameras and its data are rarely turned into images for public consumption. With particle counters and antennas and magnetometers, it studies how Earth’s sphere of space — geospace — interacts with the energy and particles Sun flying off of the Sun. The field is often referred to as space weather, but the analogies sort of fall apart when you learn that the most potent solar wind couldn’t ruffle the hair on your head. (It could wipe out your satellite, though.)

This solar wind, the namesake of the spacecraft, stretches and pulls the Earth’s magnetic aura (the magnetosphere) like a windsock. The magnetic field occasionally snaps back to energize the Van Allen radiation belts and to create the cascade of atmospheric particles that we know as aurora borealis and aurora australis (the northern and southern lights). Click on this link to a 1997 vintage computer model showing how the solar wind stirs up the magnetosphere. (Seventeen year-old GIFs below, with credit to Ramon Lopez, Chuck Goodrich, and their former science team at the University of Maryland).

magnetsim

In November 2014, Wind celebrated its 20th birthday in space. After observing our magnetic and plasma environment from several angles, it has moved back to where it started its work at the L1 Lagrange point, where the gravitational pull of the Earth and Sun cancel each other out and provide a stable orbit. Engineers say there is enough fuel to keep the spacecraft there until 2074, so Wind will keep working until the batteries or money run out.

I have a special affection for Wind, as it is one of the missions that first brought me to work at NASA. In 1997, the scientists leading the International Solar Terrestrial Physics program and the Global Geospace Science hired a young science writer to help them tell their story, and I am grateful to have had the chance. If you want to spy a bit of ancient history on the web, take a look at this old web site.

My colleague in NASA’s heliophysics division, Karen Fox, has written a great roundup of where Wind has been and all that has been accomplished with this mostly anonymous spacecraft. Go here to read her article.  If you want to dig through nearly 3,000 scholarly references to Wind data, click here.

December Puzzler Answer: Don Juan Pond

December 29th, 2014 by Adam Voiland

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Shortly after we posted our December puzzler, Dan Mahr had responded with the correct answer. “This is definitely a scene of the McMurdo Dry Valleys in Antarctica. Specifically, I think this is Wright Valley, and the body of water at center is Don Juan Pond, one of the most saline lakes in the world. The high salinity prevents the water from freezing despite the temperature being well below the freezing point of normal, non-saline water,” wrote Mahr. About an hour later, Lee Saper chimed in with a link to the Dickson et al study that helped inspire the post. Meanwhile, Edwin Clatworthy was the first of many to weigh in with the correct location on Facebook.

If you read our Image of the Day caption, you know that Don Juan’s water is the saltiest in the world. But where exactly does the water come from in such an arid environment? While scientists suspected deep groundwater bubbling up was the source for decades, the Dickson et al study comes to a different conclusion. By setting up a monitoring station that took thousands of photographs, the scientists showed that salts in the soil suck available moisture from the air through a process called deliquescence.

These water-rich salts then trickle down slopes toward the pond, often mixing with small amounts of melt water from snow and ice. Fresh melt water flows in from the west, while a briny trickle arrives from the east. For a more visual explanation of how this works, check out the two videos from Jay Dickson below. By stringing together all the photographs, you can literally see how Don Juan pond gets its water. The captions accompanying the videos are straight from Dickson’s Antarctic time-lapse research page.

Time-lapse data show water tracks hydrating at the exact moment that a front of moist air passes through Upper Wright Valley. This is confirmation that salts (specifically CaCl2) absorb water out of the atmosphere, generating brines that match the composition of Don Juan Pond, the saltiest body of water in the world.

Two months of 5-minute interval imaging allowed for detailed mapping of inputs into Don Juan Pond. Freshwater is input from the west (right), while previously undocumented seeps of brine provide input from the east (left). These pulses are controlled by diurnal spikes in surface temperature, consistent with a near-surface source. Input from deep groundwater sources was not observed.

December Puzzler

December 22nd, 2014 by Adam Voiland

decemberpuzzler2014

Update: The answer has been posted here.

Every month on Earth Matters, we offer a puzzling satellite image. The December 2014 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, 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. In the credits, we’ll acknowledge the person who was first to correctly ID the image. We’ll also recognize people 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!

AGU 2014: Urban Areas as Seen from Space

December 18th, 2014 by Kathryn Hansen

The 2014 fall meeting of the American Geological Union (AGU) is more than halfway over. Throughout the week we’ve been enjoying a series of cartoons drawn live at the meeting by Miles Traer, a multimedia producer at Stanford’s School of Earth Sciences, inspired by various sessions. Below is a cartoon from December 16 titled: “Atlas of Global Urban Change, a compendium of Earth’s rapid urbanization.” See the full collection here.

Urban Change Atlas_0 copy

Also on December 16 at AGU, scientists presented images demonstrating an aspect of urbanization that appeared less like a cartoon and a bit more festive. The images showed that city lights shine brighter during the holidays in the U.S. when compared with the rest of the year. In central urban areas, brightness was shown to increase by 20 to 30 percent, while suburbs and outskirts of major cities saw light intensity increase by 30 to 50 percent. Read more about the holiday lights images here and here.

IDL TIFF file

Picturing Science: December 17, 2014

December 17th, 2014 by Adam Voiland

Nighttime lights around many major U.S. cities shine 20 to 50 percent brighter during Christmas and New Year’s when compared to light output during the rest of the year.  Full story. Related.

swusalights_vir_2012-14

Kilauea lava flow burning through forest near Pahoa, Hawaii. Full story. Related.

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Yes, that’s a NASA plane without wings. Its top speed: 1,064 miles per hour. (Mach 1.6).  Full story.

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We like to show you snazzy pictures from the field and from space, but this is what science really looks like. AGU 2014 is on. Full story. Related.

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The occurrence of summertime fog in the eastern Pacific declined by 33 percent over the course of the 20th century, a recent study found. Full story. Related.

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“Any thunderstorm can produce gamma rays, even those that appear to be so weak a meteorologist wouldn’t look twice at them,” said Themis Chronis of the University of Alabama. Full story. Related.

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“Venus sits in the background of the Earth’s atmosphere.” — Via @AstroTerry.  Original Tweet.

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AGU 2014: The Buzz

December 16th, 2014 by Kathryn Hansen

A record 25,000 researchers and exhibitors descended on San Francisco this week for the 2014 meeting of the American Geophysical Union (AGU). That number of attendees translates to a tremendous amount of Earth science being discussed via presentations and posters, and we can’t possibly cover it all in this blog. Fortunately, this buzz word graphic posted by @AGU_Eos helped us sort what attendees are talking about, at least on twitter at #AGU14.

agu buzz words

Drought was certainly a hot topic, particularly California’s multi-year episode. NASA scientists announced at a press briefing that it would take about 11 trillion gallons of water (42 cubic kilometers)—or 1.5 times the maximum volume of the largest U.S. reservoir—to recover from the current drought. The calculation, based on data from the Gravity Recovery and Climate Experiment (GRACE) satellites, is the first of its kind. Read the full story here.

The buzz word “ice” probably stems from the abundance of research on Greenland that was presented on December 15. Scientists using ground-based and airborne radar instruments found that liquid water can now persist throughout the year on the perimeter of the ice sheet; it might help kick off melting in the spring and summer. Read more about those studies here. Look, too, at this new study that used satellite data to get a better picture of how the ice sheet is losing mass.

And finally, take a minute to browse some of the cool photos presented by Anders Bjørk of the Natural History Museum of Denmark, which included the portrait of Arctic explorers (below) and this image pair demonstrating glacial retreat in Greenland.

Arctic-History

NASA Earth Science in the News

December 10th, 2014 by Patrick Lynch

Editor’s Note: The following is an excerpt from the NASA Earth Science in the News column, published in the November/December issue of The Earth Observer newsletter. You can download the current issue here.

America’s Tiny Four Corners Region is an Outsized Methane Hotspot; TIME.com. One small spot in the U.S. Southwest is surprisingly the producer of the largest concentration of methane (CH4) gas seen across the nation. Levels of CH4 over the Four Corners region are more than triple the standard groundbased estimate of the greenhouse gas, as reported in a point study of satellite data by scientists at NASA/Jet Propulsion Laboratory (JPL) and the University of Michigan. CH4 is a heat-trapping gas whose increasing quantities in the atmosphere have fueled concerns about global climate change. The methane “hotspot,” seen on the map as a small splotch—see map above—measures approximately 6475 km2 (2500 mi2) at the junction of Arizona, New Mexico, Colorado, and Utah. For scale, the state of Arizona is about 292,668 km2 (113,000 mi2). But the area generated an annual 0.59 million metric tons of methane between 2003 and 2009—about as much CH4 as the entire coal, oil, and gas industries of the U.K. give off each year.

The Four Corners area (red) is the major U.S. hot spot for methane emissions in this map showing how much emissions varied from average background concentrations from 2003-2009 (dark colors are lower than average; lighter colors are higher). Image Credit: NASA/JPL-Caltech/University of Michigan

 

Scientists Say Ozone Layer is Recovering; Associated Press. Earth’s protective ozone layer is beginning to recover from its previously reduced levels, largely because of the phase-out since the 1980s of certain chemicals used in refrigerants and aerosol cans, a U.N. scientific panel reported. Scientists said the development demonstrates that when the world’s peoples come together, we can counteract a brewing ecological crisis. For the first time in 35 years, scientists were able to confirm a statistically significant and sustained increase in stratospheric ozone, which shields the planet from solar radiation that causes skin cancer, crop damage, and other problems. From 2000 to 2013, ozone levels climbed 4% in the key mid-northern latitudes at about 48 km (30 mi) above Earth’s surface, said scientist Paul Newman [NASA’s Goddard Space Flight Center (GSFC)].

Deep Ocean Hasn’t Warmed Measurably in a Decade, Says NASA; The Weather Channel. Deep below the ocean surface, there’s a place global warming hasn’t yet reached. According to a study published on October 5, 2014, in Nature Climate Change, scientists at NASA/Jet Propulsion Laboratory (JPL) have found that over the last decade the deepest part of the world’s ocean has not warmed measurably. The scientists analyzed ocean temperatures from between 2005 and 2013 and found that below a depth of approximately 2 km (~1.2 mi)—roughly halfway to the bottom at this location—the global ocean has not warmed nearly as quickly as the top half. The scientists collected the temperature data using both satellite measurements and data from the Argo array, a network of some 3500 floating probes scattered throughout the world that measure ocean temperatures and salinity. “The sea level is still rising,” said study coauthor Josh Willis [JPL] in a news release. “We’re just trying to understand the nitty-gritty details.”

Antarctic Sea Ice Level Breaks Record, NASA Says; CBSNews.com. Sea ice surrounding Antarctica is at an all-time high, even as global temperature averages continue to climb. NASA reports that ice formation in the continent’s southern oceans peaked this year, breaking ice-measuring satellite records dating back to the late 1970s. For the first time since 1979, on September 19, 2014, Antarctic sea ice extent exceeded ~20 million km2 (~7.7 million mi2) whereas the average maximum extent between 1981 and 2010 was ~19 million km2 (~7.3 million mi2). Despite this trend, sea ice as a whole is decreasing on a global scale. Researchers say that, just like global warming, trends have different outcomes in different parts of the world; not every location with sea ice will experience ice loss or gain. “When we think about global warming we would expect intuitively that ice should also be declining in the Antarctic region as in the Arctic,” explained senior research scientist Josefino Comiso [GSFC]. “But station and satellite data currently show that the trends in surface temperatures are most positive in the Arctic, while in the Antarctic region the trends are a mixture of positive and negative trends,” he said, adding that cooling and declining sea surface temperatures could also contribute to a “more rapid advance at the ice edge.”

1934’s Dust Bowl Drought Was the Worst in a Thousand Years for U.S.; NBCNews.com. The drought of 1934 wasn’t just bad, it was the worst. That’s the finding of a reconstruction of North American drought history over the past 1000 years, done by scientists from NASA and Columbia University’s Lamont-Doherty Earth Observatory. Their study, published in the October 17 issue of Geophysical Research Letters, concludes the drought of 1934, during the Dust Bowl years in the North American Plains, was 30% more severe than the next worst, which occurred in 1580, NASA scientists said. The scientists used tree ring records from 1000 to 2005 along with modern observations. They found that the 1934 drought extended across over 71% of western North America, compared with almost 60% during the 2012 drought. “It was the worst by a large margin,” said lead author of the study Ben Cook [NASA’s Goddard Institute for Space Studies—Climate Scientist]. The scientists found two main reasons: a winter high-pressure system over the West Coast that blocked precipitation and spring dust storms that suppressed rainfall.

GRACE Spacecraft Changed the Way Groundwater was Measured; CBS’ 60 Minutes. Leslie Stahl hosted a segment on California’s groundwater issues. The segment described the difficulty in sampling groundwater levels until NASA’s Gravity Recovery and Climate Experiment (GRACE) spacecraft was launched. Mike Watkins [JPL—GRACE Project Scientist] described how GRACE “can tell whether an area has gained water weight or lost it.” Jay Famiglietti [University of California, Irvine] said that he thought the method was “complete nonsense” until he started examining the data, which changed his position. The broadcast noted that Famiglietti was so worried by what he saw in the data that he is working “to alert governments and academics to the problem.”

November Puzzler

November 25th, 2014 by Mike Carlowicz

puzzler-November-2014

Every month we offer a puzzling satellite image, and the November 2014 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 but we can promise you credit and glory (well, maybe just credit). Roughly five days after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. In the credits, we’ll acknowledge the person who was first to correctly ID the image. We’ll also recognize people 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!