On January 12-13, 2020, Taal Volcano erupted for the first time in more than four decades. On January 22, ash plumes again emanated from Taal—but, this time, not from an eruption (seen above). According to the Philippine Institute of Volcanology and Seismology (PHIVOLCS), strong low-level winds lifted previously deposited ash lying around the volcano to heights of 5,800 meters (19,000 feet).
“Resuspension of volcanic ash is more likely at higher wind speeds, if the ash is dry and if ash particles are small,” said Simon Carn, volcanologist at Michigan Tech. “The ash deposits at Taal may have initially been quite wet, so the fact that ash resuspension is now occurring may indicate that the deposits have dried out.” The Philippines is currently in its dry season.
This time it was resuspended ash, but officials are cautious about a potential eruption again. Since its initial eruption, Taal remains on a level 4 alert, with a hazardous eruption still possible. Data show that SO₂ emissions, one of the key parameters for monitoring active volcanoes, have been present, but low, since the initial eruption. Carn said this indicates magma is most likely intruding into the main portion of the volcano, but predicting whether the magma will ultimately erupt is challenging.
If the volcano erupts again, it could look different than the early January event. During that “wet” eruption, water from the nearby crater lake covered the ash particles with water droplets. Wetter eruptions tend to produce finer ash particles. However, nearly all of the water in the main crater is now gone. According to Carn, the lake could have vaporized from the heat of the emanating magma; some could have been physically ejected by the previous eruption; and some could have drained through fractures or fissures in the volcano. In the absence of water, this volcano could produce a “dry” eruption, which would make comparatively larger ash particles.
NASA was mostly shut down for January 2019, but Earth wasn’t. In case you missed it, here are some of the big stories we didn’t cover during the impasse.
Scientists Find Evidence of An Ancient Earth Rock on the Moon Four billion years ago, the Moon was about three times closer to Earth than it is now. So if a large asteroid or comet slammed into Earth and jettisoned material into space, it was more likely that rock fragments might end up landing on the Moon. That’s how an international team of scientists working with the Center for Lunar Science and Exploration (CLSE) think that a small fragment composed of quartz, feldspar, and zircon—a combination of minerals commonly found on Earth—ended up embedded within a larger Moon rock collected by Apollo astronauts. The team recently revealed evidence from the ancient rock fragment, suggesting that it is one of the oldest Earth rocks ever found.
A Rare Typhoon Hits Thailand It is rare for powerful tropical storms to strike Thailand. Before January 2019, the last time it happened was 1962. So meteorologists took notice when Tropical Storm Pabuk slammed into southern Thailand on January 4, 2019, packing sustained winds of 95 kilometers per hour (60 mph) and delivering torrential rains to some of Thailand’s most popular tourist destinations. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image of the storm on January 4, 2019.
Snow Falls in Algeria (Yes, the Sahara) In another unusual weather event, fresh snow created surreal scenery in Algeria when it coated Saharan desert dunes in mid-January. This is just the third time snow has fallen in Ain Sefra, the gateway to the Sahara Desert, in the past 37 years. (The last time was 2018.) The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured an image of the snow on January 14, 2019. It is composed with false color, using a combination of infraed and visible light (MODIS bands 7-2-1). Snow appears blue with this band combination.
China’s War on Particulates May Be Making Ozone Pollution Worse For the past few years, China has advanced an ambitious plan to reduce emissions of fine particulate (PM2.5), a harmful type of air pollution. Authorities have restricted the number of vehicles on the roads, capped how much coal industries can burn, and shuttered many polluting factories and power plants. The result has been impressive: over five years, concentrations of PM2.5 in eastern China have fallen nearly 40 percent. But, there is another wrinkle. Particulates also sponge up substances that make it harder for ground-level ozone to form. So even as concentrations of PM2.5 decline, ozone concentrations are rising, new research shows.
Can Satellites SensePoverty? Increasingly, yes, at least in rural areas. By analyzing observations of villages in Kenya, one team of researchers recently showed that land use and land cover data from satellites contains some useful clues for identifying the poorest households in rural areas. Key indicators included: the size of buildings within a homestead, the amount of bare agricultural land adjacent to a homestead, and the length of the growing season. The researchers think this type of information could make it easier to monitor the progress of efforts designed to reduce poverty in rural areas, such as the U.N. Sustainable Development Goals.
Urban Heat Islands Come with a Cost The urban heat island effect has been shown to raise the temperature of cities compared to their neighboring rural and semi-rural areas. Research published in May 2017 in Nature Climate Change spells out the cost associated the effect. Economists analyzed 1,692 cities and found that the economic cost of climate change this century could be 2.6 times larger when the heat island effect is accounted for. The costs stem from factors like air pollution, water quality, and energy for cooling.
CO2 Reached Record Highs In April 2017, the concentration of carbon dioxide in the atmosphere reached (and surpassed) 410 parts per million (ppm) for the first time in recorded history. The milestone measurement was made at the Mauna Loa Observatory in Hawaii, a ground-based station that has collected CO2 data since 1958. (Global, space-based data now supplement those measurements and provide the big-picture view.)
Levels continued to rise, and by the end of May, the monthly average was the highest on record at 409.65 ppm. CO2 concentrations reach an annual peak every May, but the average in May 2017 was well above that of previous years. Check out this graph to see how 2017 has measured up.
Rainfall Reorg Climate change is likely to affect Earth’s rainfall patterns. Authors of a recent study published in Science Advances used paleoclimate data to examine how rainfall patterns have responded to past climate shifts. These past trends lend evidence to scenarios that could unfold in the future. During the northern hemisphere’s summer, dry areas are likely to become drier and wet areas would be wetter; in the winter, regions of relatively heavy rainfall would expand northward.
Plants Pack a Punch on Precipitation During photosynthesis, plants release water vapor into the air. This water vapor can ultimately cause clouds to form, which in turn can affect Earth’s energy balance and produce precipitation. A May 2017 study published in Nature Geoscience used global satellite data and a statistical technique to show that as much as 30 percent of the variability in climate and weather patterns can be attributed to plants.
“Hottest” Events on the Rise Scientists have developed a framework to help determine if an extreme weather events can be attributed to climate change. Using the framework, they show that for 80 percent of areas where observations are available, global warming has increased the chances for (and severity of) “hottest” events—months and days that measure in as the hottest of the year. The research was published May 2017 in Proceedings of the National Academy of Sciences.
The DC-8’s four engines burned either JP-8 jet fuel or a 50-50 blend of JP-8 and renewable alternative fuel made from camelina plant oil.Credits: NASA/SSAI Edward Winstead
Taking Some of the Search Out of ‘Search and Rescue’
NASA engineers are developing prototypes of second-generation locator beacons. The little devices have been used by pilots, mariners, and hikers since the 1970s to relay distress signals in times of emergency. Until now, those beacons have had a 2-kilometer (1 mile) radius. The new beacons will pinpoint location within a 140-meter radius—that’s more than 10 times more precise.
Small Satellites Will Track Big Storms
Atlantic hurricane season has just begun—and the CYGNSS mission has it covered. The constellation of eight mini-satellites, launched into low-Earth orbit in December 2016, measures surface winds using GPS signals reflected from the ocean surface. The data will help track storms as they grow, giving forecasters a better sense of storm intensity.
Long a source of wonder (and occasional conspiracy theories), the white plumes that trail behind aircraft are a focus of study for NASA scientists testing the effects of biofuels. A new study shows that alternative fuels made from plant oils can cut down on particle emissions in jet exhaust by as much as 50 to 70 percent. From the news release:
Contrails are produced by hot aircraft engine exhaust mixing with the cold air that is typical at cruise altitudes several miles above Earth’s surface, and are composed primarily of water in the form of ice crystals…Researchers are most interested in persistent contrails because they create long-lasting, and sometimes extensive, clouds that would not normally form in the atmosphere, and are believed to be a factor in influencing Earth’s environment.
A Different Kind of Scat
Scientists have a new tool for measuring both ocean winds and water currents. Tested on airborne missions this spring, DopplerScatt is a cousin of QuickSCAT and RapidScat, which used a scatterometer to measure the “roughness” of the ocean surface and determine the direction and intensity of wind. DopplerScat adds a doppler radar to the package, allowing scientists to measure the speed and direction of the moving water. The instrument is another potential tool to measure currents along shipping routes or predict the direction that oils and other slicks might move.
The Gulf of Mexico, like any sea, is rich in dissolved salts. Unlike most seas, the Gulf also sits atop a big mound of salt. Left behind by an ancient ocean, salt deposits lie beneath the Gulf seafloor and get pressed and squeezed and bulged by the heavy sediments laying on top of them. The result is pock-marked, almost lunar-looking seafloor. The many mounds and depressions came into clearer relief this spring with the release of a new seafloor bathymetry map compiled from oil and gas industry surveys and assembled by the U.S. Bureau of Ocean Energy Management.
3D Water Babies
NASA’s Scientific Visualization Studio took a look back at conditions in the Pacific Ocean in 2015-16, which included the arrival and departure of both El Nino and La Nina. The 3D visualizations were derived from NASA’s Modern-Era Retrospective Analysis for Research and Applications (MERRA) dataset, a global climate modeling effort that is built from remote sensing data.
In other Nino news, a research team led by NASA Langley scientists found that the strong 2015-2016 El Niño lofted abnormal amounts of cloud ice and water vapor unusually high into the atmosphere, creating conditions similar to what could happen on a larger scale in a warming world.
Not the Kind of Brightening You Want to See
For past few years, warm ocean temperatures in the western Pacific Ocean have wrecked havoc on the Great Barrier Reef. Extreme water temperatures can disrupt the symbiotic partnership between corals and the algae that live inside their tissues. This leads the colorful algae to wash out of the coral, leaving them bright white in what scientists refer to as “bleaching” events. The health of coral reefs is usually monitored by airborne and diver-based surveys, but the European Space Agency recently reported that scientists have been able to use Sentinel 2 data to identify a bleaching event on the Great Barrier Reef. Such satellite monitoring could prove especially useful for monitoring reefs that are more remote and not as well studied as those around Australia.
Eyeing the Fuel for Hurricane Season
On June 1, the beginning of Atlantic Hurricane Season, the National Oceanic and Atmospheric Administration released a map of sea surface temperatures in the Caribbean, the Gulf of Mexico, and the tropical North Atlantic Ocean. The darkest orange areas indicate water temperatures of 26.5°C (80°F) and higher — the temperatures required for the formation and growth of hurricanes. Forecasters are expecting a hurricane season that is a bit more active than average.
(Finger)Prints of Tides
In a new comprehensive analysis published in Geophysical Research Letters, a French-led research team found that global mean sea level is rising 25 percent faster now than it did during the late 20th century. The increase is mostly due to increased melting of the Greenland Ice Sheet. A big part of the study was a reanalysis and recalibration of data acquired by satellites over the past 25 years, which are now better correlated to surface-based measurements. The study found that mean sea level has been increasing by 3 millimeters (0.1 inches) per year. The American Geophysical Union published a popular summary of the study.
Here’s a roundup of some of the latest Earth science news from NASA.
ANATOMY OF A TSUNAMI
When it comes to generating a tsunami, it’s not just the vertical movement of the seafloor that matters. Research performed in a giant tank showed that horizontal movement also contributes to the formation and strength of these potentially destructive waves. See the wave tank in the video below, and read more about the research here.
NASA data contributed to a study led by University of Texas researchers, which shows that the amount of ice lost by glaciers in Greenland depends on their shape. They found that the thick, wide parts of glaciers lose ice more easily than the thin, steep portions. Read more here.
SATELLITE SEES A SOLITARY CONTRAIL
And last but not least, check out this image from Landsat 8 posted to Twitter by @andrewmiskelly. The scene shows a “solitary contrail” over western Queensland, Australia.
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.
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.
“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.
Global atmospheric concentrations of methane are rising—along with scientific scrutiny of this potent greenhouse gas. In March 2016, we published a feature story that took a broad look at why methane matters. Since that story came out, several new studies have been published. But first, some broader context from that feature story…
The long-term, global trend for atmospheric methane is clear. The concentration of the gas was relatively stable for hundreds of thousands of years, but then started to increase rapidly around 1750. The reason is simple: increasing human populations since the Industrial Revolution have meant more agriculture, more waste, and more fossil fuel production. Over the same period, emissions from natural sources have stayed about the same.
The Zeppelin Observatory in Svalbard monitors methane concentrations. It is one of several stations that helps scientists assemble a global picture of atmospheric aerosols and pollutants. Photo courtesy of AGAGE.
If you focus on just the past five decades—when modern scientific tools have been available to detect atmospheric methane—there have been fluctuations in methane levels that are harder to explain. Since 2005, methane has been on the rise, and no one is quite sure why. Some scientists think tropical wetlands have gotten a bit wetter and are releasing more gas. Others point to the natural gas fracking boom in North America and its sometimes leaky infrastructure. Others wonder if changes in agriculture may be playing a role.
A combination of historical ice core data and air monitoring instruments reveals a consistent trend: global atmospheric methane concentrations have risen sharply in the past 2000 years. (NASA Earth Observatory image by Joshua Stevens, using data from the EPA.)
The stakes are high when it comes to sorting out what is going on with methane. Global temperatures in 2014 and 2015 were warmer than at any other time in the modern temperature record, which dates back to 1880. The most recent decade was the warmest on the record. The current year, 2016, is already on track to be the warmest. And carbon emissions — including methane — are central to that rise.
Atmospheric methane has continued to increase, though the rate of the increase has varied considerably over time and puzzled experts. (NASA Earth Observatory image by Joshua Stevens, using data from NOAA.)
Isotope Data Suggests Fossil Fuels Not to Blame for Increase
Methane bubbles up from swamps and rivers, belches from volcanoes, rises from wildfires, and seeps from the guts of cows and termites (where is it made by microbes). Human settlements are awash with the gas. Methane leaks silently from natural gas and oil wells and pipelines, as well as coal mines. It stews in landfills, sewage treatment plants, and rice paddies. With so many different sources, many scientists who study methane are hesitant to pin the rising concentration of the gas on a particular source until more data is collected and analyzed.
However, an April 2016 study led by a researcher from New Zealand’s National Institute of Water and Atmospheric Research came down squarely on one side. After measuring the isotopic composition, or chemical structure, of carbon trapped in ice cores and archived air samples from a global network of monitoring stations, the scientists concluded that blaming the rise in atmospheric methane on fossil fuel production makes little sense.
When methane has extra neutrons in its chemical structure, it is said to be a “heavier” isotope; fewer neutrons make for “lighter” methane. Different processes produce different proportions of heavy and light methane. Lighter isotopes of a carbon (meaning they have a lower ratio of Carbon 13 to Carbon 12 than the atmosphere), for instance, are usually associated with methane recovered from fossil fuels.
As shown in the chart above, the authors observed a decrease in the isotopes associated with fossil fuels at all latitudes beginning in 2006. But at the same time, global concentrations of methane (blue line in the top chart) have risen. “The finding is unexpected, given the recent boom in unconventional gas production and reported resurgence in coal mining and the Asian economy. Either food production or climate-sensitive natural emissions are the most probable causes of the current methane increase,” the authors noted.
If fossil fuel production is not responsible for increasing concentrations of atmospheric methane, than what is? The authors say that more research is needed to be certain, but that there are indications that the agricultural sector in southeast Asia (especially rice cultivation and livestock production) is likely responsible.
Large Increase in U.S. Emissions over Past Decade A March 2016 study led by Harvard researchers based on surface measurements and satellite observations detected a 30 percent increase in methane emissions from the United States between 2002 and 2014 — an amount the authors argue could account for between 30 to 60 percent of the global growth in atmospheric methane during the past decade.
The most significant increase (in red, as observed with Japan’s Greenhouse Gases Observing Satellite) occurred in the central United States. However, the authors avoid making claims about why. “The U.S. has seen a 20 percent increase in oil and gas production and a nine-fold increase in shale gas production from 2002 to 2014, but the spatial pattern of the methane increase seen by GOSAT does not clearly point to these sources. More work is needed to attribute the observed increase to specific sources.”
First Time Satellite View of Methane Leaking from a Single Facility For the first time, an instrument on a spacecraft has measured the methane emissions leaking from a single facility on Earth’s surface. The observation, detailed in a June 2016 study, was made by the hyperspectral spectrometer Hyperion on NASA’s Earth Observing-1 (EO-1) satellite. On three separate overpasses, Hyperion detected methane leaking from the Aliso Canyon gas leak, the largest methane leak in U.S. history.
“The percentage of atmospheric methane produced through human activities remains poorly understood. Future satellite instruments with much greater sensitivity can help resolve this question by surveying the biggest sources around the world and helping us to better understand and address this unknown factor in greenhouse gas emissions,” David Thompson, an atmospheric chemist at NASA’s Jet Propulsion Laboratory and an author of the study. For instance, the upcoming Environmental Mapping and Analysis Program (EnMAP) is a satellite mission (managed by the German Aerospace Center) that will provide new hyperspectral data for scientists for monitoring methane.
As detailed in a July 2016 study, scientists and engineering are also working on a project called GEO-CAPE that will result in the deployment of a new generation of methane-monitoring instruments on geostationary satellites that can monitor methane sources in North and South America on a more continuous basis. Current methane sensors operate in low-Earth orbit, and thus take several days or even weeks before they can observe the same methane hot spot. For instance, EO-1 detected the Aliso Canyon plume just three times between December 29, 2015 and February 14, 2016, due to challenges posed by cloud cover and the lighting angle. A geostationary satellite would have detected it on a much more regular basis.
I live in the Ketapang district of West Kalimantan. We had some serious fires here, but it wasn’t as bad as in Central Kalimantan, which was basically the epicenter of the disaster. Breathing the smoke wasn’t pleasant, and I didn’t dare open a window or a door in my house because it would just permeate everything.
The smoke also seriously disrupted some of my travel plans. There were no flights into or out of my town for at least a month, so we had to rely on boats or long-distance travel by car.
The smoke also disrupted my work. I do lot in the community and in schools, but September and October were quiet months for us because the schools were not in session. It was too dangerous for students. Adults were not available to participate in our conservation activities and meetings because they either had to stay in the field and guard their crops from fire, or didn’t want to be outside more then necessary.
Have you had health problems as a result of the haze? Do you know people who have?
I had a cough for several weeks. I do know people whose children were sick, and one woman I spoke to has a three-month old baby that she has not taken outside at all because of the smoke. One problem was that there just weren’t enough good masks to go around. During the worst of the pollution, normal surgical masks aren’t enough. But many people don’t own the N95 masks that block out the smoke particles.
Can you describe how the air smelled and tasted during the worst of the burning?
Acrid is the best word to describe it. Peat fires have a pretty distinctive smell. The smoke just goes right to the back of your throat, and makes your eyes sting. People here describe it has having mata pedas, which translates to “spicy eyes.” The smoke looks like morning fog, but it doesn’t dissipate.
A peat fire burns vegetation in the Sungai Laur area of Ketapang district, West Kalimantan. (Photo courtesy of the Gunung Palung Orangutan Conservation Program).
Is there anything else you would like to add?
I am afraid that the next huge hot spots—not this year, but maybe in the future—will be in Papua. And there, as someone has pointed out to me, there are no charismatic species to get people riled up and to motivate them to donate to conservation. There’s just peat. Most of the peatlands there are still intact, too, and they absolutely need to be protected.
You can read blog posts by Cassie Freund about the fires here and here.