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.
At the time of his death on December 23, 2016, Piers Sellers was the deputy director of the Sciences and Exploration Directorate and the acting director of the Earth science division at NASA’s Goddard Space Flight Center. But he was a lot more than that to his colleagues and to the world. NASA science writer Patrick Lynch (and occasional Earth Observatory contributor) had the unenviable task of trying to capture the essence of Sellers:
“As an astronaut, he helped build the International Space Station. As a manager, he helped lead hundreds of scientists. And as a public figure he was an inspiration to many for his optimistic take on humanity’s ability to confront Earth’s changing climate. But his most lasting contributions will be in the field where he began his career: science.”
Piers came to NASA Goddard from Britain in 1982 as a research meteorologist and climate scientist. His focus was the interaction between the biosphere — the living, breathing plant-life of Earth — and the atmosphere. He helped develop models and wrote several papers that are still widely cited in the field. But he also had another lifelong dream: to become an astronaut. He applied to the astronaut training program in the 1990s, and worked through rigorous screening and training to go into space. He flew to the International Space Station in 2002, 2006, and 2010, participating in six spacewalks and helping with assembly of the station. Upon retiring from the astronaut corps, he came back to Goddard and resumed his place as a leader in Earth science, while also promoting conversations and collaborations with researchers studying planetary science and hunting for life beyond our solar system.
I did not have the chance to get to know Piers well. He was someone I mostly watched from afar and our interactions were sporadic, though always interesting, dignified, and thoughtful. I came to know him mostly through his words — to the media and to my fellow scientific and communications staff of NASA Goddard — and in the ways he inspired people. The more I read, the more I wish I had been able to spend more time with him.
In January 2016, one year ago this week, he wrote a poignant op-ed in The New York Times. The words were a compelling prelude to his final year with us.
I’m a climate scientist who has just been told I have Stage 4 pancreatic cancer. This diagnosis puts me in an interesting position. I’ve spent much of my professional life thinking about the science of climate change, which is best viewed through a multi-decadal lens. At some level I was sure that, even at my present age of 60, I would live to see the most critical part of the problem, and its possible solutions, play out in my lifetime. Now that my personal horizon has been steeply foreshortened, I was forced to decide how to spend my remaining time. Was continuing to think about climate change worth the bother?
In the summer of 2016, Sellers wrote another compelling piece, this time in The New Yorker. In “Space, Climate Change, and the Real Meaning of Theory,” he took on a very sensitive and fundamental facet of science: the accumulation of evidence and observation that leads to truth. Here is my favorite passage:
When we talk about why the climate has changed, and what the future climate is likely to be, scientists use analyses and predictions that rest heavily on results from computer models, which in turn rest on layers and layers of theory. And there’s the rub—a lot of the confusion about what is known and unknown about the changing climate can be traced to people’s understanding of the role of theory in science.
Fundamentally, a theory in science is not just a whim or an opinion; it is a logical construct of how we think something works, generally agreed upon by scientists and always in agreement with the available observations. A good example is Isaac Newton’s theory of gravitation, which says that every physical object in the universe exerts a gravity force field around itself, with the strength of that field depending on its mass. The theory—one simple equation—does a superb job of explaining our observations of how planets orbit around the sun, and was more than good enough to make the calculations we needed to send spacecraft to the moon and elsewhere. Einstein improved on Newton’s theory when it comes to large-scale astronomical phenomena, but, for everyday engineering use, Newton’s physics works perfectly well, even though it is more than three hundred years old.
…Engineering theory, based on Newton’s work, is so accepted and reliable that we can get it right the first time, almost every time. The theory of aerodynamics is another perfect example: the Boeing 747 jumbo-jet prototype flew the first time it took to the air—that’s confidence for you. So every time you get on a commercial aircraft, you are entrusting your life to a set of equations, albeit supported by a lot of experimental observations. A jetliner is just aluminum wrapped around a theory.
On camera, it is easy to pick up the energy, humor, and dignity of the man. In the past year, he was a frequent interview subject for the television and radio media. He also made an appearance in Leonardo DiCaprio’s documentary Before the Flood. Some of us think Piers stole the show.
But I am most fond of this simple video, posted last month to YouTube. It’s a conversation between Piers and Compton Tucker, one of his best friends, his next-door neighbor, and a fellow NASA scientist. So many people have stilted and distant impressions about scientists, and Hollywood caricatures don’t help. I like this video because it shows bright people having fun, being human, and savoring life, learning, and friendship.
At the conclusion of his January 2016 piece in The New York Times, Piers offers a thought that inspires us to keep up the good work.
As for me, I’ve no complaints. I’m very grateful for the experiences I’ve had on this planet. As an astronaut I spacewalked 220 miles above the Earth. Floating alongside the International Space Station, I watched hurricanes cartwheel across oceans, the Amazon snake its way to the sea through a brilliant green carpet of forest, and gigantic nighttime thunderstorms flash and flare for hundreds of miles along the Equator. From this God’s-eye-view, I saw how fragile and infinitely precious the Earth is. I’m hopeful for its future.
October 18th, 2016 by Michael Cabbage & Leslie McCarthy
September 2016 was the warmest September in 136 years of modern record-keeping, according to a monthly analysis of global temperatures by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York.
September 2016’s temperature was a razor-thin 0.004 degrees Celsius warmer than the previous warmest September in 2014. The margin is so narrow those two months are in a statistical tie. Last month was 0.91 degrees Celsius warmer than the mean September temperature from 1951-1980.
The record-warm September means 11 of the past 12 consecutive months dating back to October 2015 have set new monthly high-temperature records. Updates to the input data have meant that June 2016, previously reported to have been the warmest June on record, is, in GISS’s updated analysis, the third warmest June behind 2015 and 1998 after receiving additional temperature readings from Antarctica. The late reports lowered the June 2016 anomaly by 0.05 degrees Celsius to 0.75.
“Monthly rankings are sensitive to updates in the record, and our latest update to mid-winter readings from the South Pole has changed the ranking for June,” said GISS director Gavin Schmidt. “We continue to stress that while monthly rankings are newsworthy, they are not nearly as important as long-term trends.”
The monthly analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments measuring sea surface temperature, and Antarctic research stations. The modern global temperature record begins around 1880 because previous observations didn’t cover enough of the planet. Monthly analyses are updated when additional data become available, and the results are subject to change.
September 12th, 2016 by Leslie McCarthy & Michael Cabbage
August 2016 was the warmest August in 136 years of modern record-keeping, according to a monthly analysis of global temperatures by scientists at NASA’s Goddard Institute for Space Studies (GISS).
Although the seasonal temperature cycle typically peaks in July, August 2016 wound up tied with July 2016 for the warmest month ever recorded. August 2016’s temperature was 0.16 degrees Celsius warmer than the previous warmest August (2014). The month also was 0.98 degrees Celsius warmer than the mean August temperature from 1951-1980.
“Monthly rankings, which vary by only a few hundredths of a degree, are inherently fragile,” said GISS Director Gavin Schmidt. “We stress that the long-term trends are the most important for understanding the ongoing changes that are affecting our planet.” Those long-term trends are apparent in the plot of temperature anomalies above.
The record warm August continued a streak of 11 consecutive months (dating to October 2015) that have set new monthly temperature records. The analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments measuring sea surface temperature, and Antarctic research stations. The modern global temperature record begins around 1880 because previous observations didn’t cover enough of the planet.
Many of the Olympic festivities are taking place in Barra da Tijuca, one of the youngest and most affluent neighborhoods in Rio. Credit: Landsat 8/NASA Earth Observatory.
While gymnasts leap, cyclists pedal, and divers twirl for Olympic gold in Rio de Janeiro, sensors on several NASA Earth Observing satellites are catching glimpses of the city and its surroundings from space. The mix of satellites and sensors in orbit are nearly as varied and diverse as the athletes competing below.
The marathoner among NASA’s fleet would have to be Terra. Despite having a design life of six years, this reliable spacecraft has been in orbit since 2000. The multi-purpose satellite carries five scientific payloads and monitors everything from phytoplankton to forest cover to airborne particles called aerosols.
The swimmers would have to be Aquarius, Aqua, and the Global Precipitation Measurement (GPM). All three satellites, as their names suggest, specialize in studying water. Aquarius focuses on measuring the ocean’s salinity. Aqua, like Terra, is versatile: It studies water vapor, sea ice, snow ice, clouds, and more. GPM is the newest of the trio. Launched in 2014, it makes global maps of precipitation and sets standards for precipitation measurements worldwide.
The synchronized divers of space would have to be the Gravity Recovery and Climate Experiment (GRACE). While divers seem to temporarily defy gravity with their flips and turns, the pair of GRACE satellites actually measures Earth’s gravity from space.
The twin GRACE satellites. Credit: NASA
The archers would be CALIPSO and CloudSat. These two satellites shoot laser pulses (CALIPSO) and radar waves (CloudSat) down toward features in the atmosphere such as clouds and smoke plumes. They measures precisely how long it takes for the light or radio waves to bounce back, making it possible to map the vertical structure of the atmosphere.
The images above and below offer a glimpse of some of the types of imagery and data that NASA-Earth observing satellites collect. The image at the top of the page shows how Olympic Park in Rio appeared to the Operational Land Imager (OLI), a sensor on Landsat 8. The image immediately above shows Rio at night as seen by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. The instrument can sense light 100,000 times fainter than conventional visible-light sensors, making it extremely sensitive to moonlight and city lights.
The image directly above shows a view of Rio and Guanabara Bay on August 6, 2016, the day after the opening ceremony. The fourth image (below) shows a view of aerosols observed over Rio by the Multi-Angle Imaging Spectrometer (MISR) on August 2, 2016.
Scientists at NASA and officials in the Rio de Janeiro government recently signed an agreement about natural hazards preparedness. The hope is that satellite imagery and data—in conjunction with in situ data from the ground—will help scientists better understand, anticipate, and monitor drought, flooding, and landslides that occur in and around Rio. The collaboration will focus on integrating, visualizing, and sharing relevant data from NASA satellites.
Severe mudslides and landslides affected Rio in 2011. Read more about this image here. Credit: EO-1/NASA Earth Observatory
In a NASA press release, Rio de Janeiro Mayor Eduardo Paes said that his city has historically suffered from massive rainstorms and subsequent floods and landslides, all of which can cause casualties and disrupt the economy. Discussions are underway to address those hazards and to plan future cooperative activities.
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The 2015 fire season was the most severe ever observed by NASA Earth Observing System satellites, a new study shows. As we reported in December, 2015 was an intense fire season in Indonesia because the drying effects of El Niño exacerbated seasonal fires lit by growers. Many farmers lost control of fires, which then spread through dried-out peat deposits. Peat fires produce thick, acrid smoke rich with greenhouse gases.
Some of the results from their analysis are shown in the chart below. Note that red lines indicate trends in 2006 (also a severe fire year); blacks lines indicate 2015. The tick marks on the X-axis indicate the month of the year. Comparing the two years, it is clear that 2015 was the more severe fire season. The sensors generally detected higher levels (or longer duration of emissions) of each pollutant in 2015. The peak number of fires observed by MODIS was slightly higher in 2006, but the sensor detected more fires overall in 2015. In both 2006 and 2015, fire activity increased rapidly as rainfall decreased.
To see how the 2015 fires compared to severe fire seasons before the Earth Observing System satellites were in space, Goddard Institute for Space Studies scientist Robert Field looked back at longer-term records of visibility collected at Indonesian airports. The chart below compares visibility in 2015 with 1997 and 1991—two other years that were dry because of El Niño. (Note: Bext stands for extinction coefficient; a higher extinction coefficient means more smoke was in the air. The upper part of the chart shows how much rain fell. In that chart, “CPC pcp” stands for precipitation from the Climate Prediction Center, a NOAA research group.) By that measure, 1997 was a far more severe fire season. In Sumatra, visibility was also lower in 1991, though in Kalimantan. visibility was about the same in 2015 and 1991.
“Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Niño events,” the authors emphasized.
+Read a NASA press release about the study here.
+Read a more detailed story about the 2015 fires here.
In Indonesia, dry weather can mean fire. September 2015 data from the TRMM satellite shows lack of rainfall in the areas where fire broke out. Image by NASA Earth Observatory.
March 17th, 2016 by Adam Voiland and Holli Riebeek
Fourteen years ago, a rocket launched a pair of satellites known as the Gravity Recovery and Climate Experiment (GRACE) from the Plesetsk Cosmodrome in Russia. Though just 487 kilograms (1,074 pounds) each, the satellites have produced out-sized scientific advances. As we noted in 2012, few hydrologists believed the satellites would be able to detect—no less measure—changes in groundwater when they launched. As the map below shows, scientists working with GRACE data have shown otherwise.
This map shows how water supplies have changed between 2003 and 2012. GRACE measures subtle shifts in gravity from month to month. Variations in land topography or ocean tides change the distribution of Earth’s mass; the addition or subtraction of water also changes the gravity field. During that period, groundwater supplies decreased in California’s Central Valley and in the Southern High Plains (Texas and Oklahoma)—places that rely on ground water to irrigate crops. Eastern Texas, Alabama, and the Mid-Atlantic states also saw a decrease in ground water supplies because of long-term drought. The flood-prone Upper Missouri basin, on the other hand, stored more water over the decade.
GRACE has observed a number of significant changes in the water cycle. For instance, the mission revealed losses in ice mass on Greenland (where the loss is dramatic), Alaska, and Antarctica. The gravity measurements revealed how much the melting glaciers are contributing to sea level rise by recording both ice lost from land and the mass gained in the ocean. The image below shows changes in the Antarctic ice sheet between 2003 and 2010 as measured by GRACE.
GRACE measured changes in the Antarctic ice sheet from December 2003 through 2010. Red areas lost mass, while blue regions gained mass. (NASA map adapted from Luthke et al., 2012.)
As seen in the set of maps below, GRACE-based measurements can also be combined with ground-based measurements to map water at the surface, in the root zone, and as groundwater.
These maps compare conditions during the week of August 20, 2012, to the long-term average from 1948 to the present. For example, dark red regions represent dry conditions that should occur only 2 percent of the time (once every 50 years).
Thank you, GRACE! Here’s to many more years of observations. You can learn more about the mission here. Launch and clean room photos available here.
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The statistical record is notable, but keep in mind that this year is just part of a much longer story about the climate. If you want to learn more about climate science as a whole rather than just the latest headlines, here are a few resources that you may find informative. The list is not comprehensive (and we are open to more suggestions), but it is a useful starting point for understanding climate science.
The plot above comes from an interactive graphic called “What’s Really Warming the World?” Put together by Eric Roston and Blacki Migliozzi of Bloomberg News (with assistance from NASA climatologists Gavin Schmidt and Kate Marvel), the chart does an excellent job of breaking down the various factors (greenhouse gases, aerosols, solar activity, orbital variations, etc.) that affect climate. It parses out visually how much each factor contributes. The bottom line: greenhouse gases are absolutely central to explaining global temperature trends since 1880. The screenshot above hints at what the interactive looks like, but I highly recommend heading over to Bloomberg to see the full graphic.
Another invaluable graphic for understanding climate change is the “radiative forcing bar chart” below. (You can read an interesting post by Schmidt that explains how these charts have evolved over the decades). At first glance, the chart from the fifth assessment report by the United Nations’ Intergovernmental Panel on Climate Change may seem technical and difficult to understand. It is. But it is well worth looking up the technical terms.
In short, you are looking at a balance sheet of the major types of emissions that have either a warming or cooling effect on climate. Bars that extend to the left of the 0 signify a cooling effect; bars that extend to the right signify warming. The longer the bar, the more warming or cooling a given type of emissions contributes. What becomes immediately obvious is that carbon dioxide (CO2) and methane (CH4) have the biggest warming influence by far. The other well-mixed greenhouse gases — halocarbons, nitrous oxide (N20), chlorofluorocarbons (CFCs), and hydrochlorofluorocarbons (HCFCs) play a much smaller role.
The situation gets messy when you look at the role that short-lived gases and aerosols play. Some gases like carbon monoxide (CO) and the non-methane volatile organic compounds (NMVOC) — such as benzene, ethanol, formaldehyde — contribute to warming, but not much. Others like NOx actually slightly cool the climate overall if you consider how these gases interact with other substances in the atmosphere. Things get even messier if you look at aerosols. Mineral dust, sulfate, nitrate, and organic carbon have a cooling effect. On the other hand, black carbon causes warming. Albedo changes due to land use and changes in solar irradiance are minor in comparison to the other factors.
That’s a lot of variables, but one reason I like this chart is the error bars and the “level of confidence” column. The error bars give you a sense of how much uncertainty there is when it comes to the effects of various emissions. Look at the aerosol section, for instance, and you will see that the error bars are quite large and there is still some uncertainty about how aerosols affect clouds. The level of confidence column offers further clues to what scientists understand well and which areas they are less confident about. VH stands for very high confidence; H stands for high confidence; M stands for medium confidence; and L stands for low confidence.
What is striking is that even when you account for the error bars, there is little doubt that carbon dioxide and methane are warming the climate.
A third graphic, produced by NASA but based on data described here, is particularly compelling. Based on atmospheric information preserved in air bubbles in ancient ice cores, the plot offers a view of carbon dioxide levels in Earth’s atmosphere for the past 400,000 years. As this graph makes obvious, it has been a long time since carbon dioxide levels have been anywhere near where they are now.
For a much more recent view of carbon dioxide levels, the animation above is useful. Produced by NASA’s Scientific Visualization Studio, the video shows a time-series of the distribution and concentration of carbon dioxide in the mid-troposphere, as observed by the Atmospheric Infrared Sounder (AIRS) on the Aqua spacecraft. For comparison, the fluctuations in AIRS data is overlain by a graph of the seasonal variation and interannual increase of carbon dioxide observed at the Mauna Loa observatory in Hawaii. You can clearly see seasonal variations in carbon dioxide levels, but notice also that the mid-tropospheric carbon dioxide shows a steady increase in atmospheric carbon dioxide concentrations over time. That increase is because of human activity.
My last recommendation will take longer for you to get through, but it is an invaluable resource. Physicist Spencer Weart offers a detailed but understandable account of the history of climate science research in his book The Discovery of Global Warming. You can read an extended version of book online on the American Institute of Physics’ website. If you make it all the way through, you will know far more than most people about the climate.
Photo by William Hrybyk for NASA’s Goddard Space Flight Center.
Earth Observatory has a pretty small staff — seven people — for a daily publication. There are a lot of other folks inside and outside of NASA who help us find and tell stories, but one man stands out from the rest. We might not be able to bring you a new Image of the Day, every day, if it were not for the unsung, unofficial eighth member of our team: Jeff Schmaltz. Our colleagues at NASA Goddard Space Flight Center (GSFC) have just published a Q&A with Jeff, and we thought you should know more about him.
“Curious Jeff” Schmaltz is on his third career.
What do you do and what is most interesting about your role here at Goddard? How do you help support Goddard’s mission?
Our group provides real-time Earth imagery from NASA Earth-observing satellites. The data is transmitted from the satellites to the ground stations, then to NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and then to the near-real-time data processing system. The data is basically numbers that we convert to images which we place on NASA websites such as https://worldview.earthdata.nasa.gov.
Our images come from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument flying on the Aqua and Terra satellites. Each satellite covers the entire Earth every day, so we receive two complete images of the Earth daily. From the time the satellite acquires data to the time we put the image on our website is roughly three to four hours.
What is your education?
I have three master’s degrees, one each in wildlife management, computer science and remote sensing.
Please tell us about your three different careers.
Since I was a kid in Connecticut, I wanted to work in the outdoors with animals. I got a master’s in wildlife management and then worked as a wildlife biologist for the U.S. Forest Service in the Daniel Boone National Forrest in Somerset, Kentucky. We counted endangered woodpeckers and maintained the forest. I spent all day outside walking through the forest and then came in later to do the paperwork.
I returned to school to get a master’s in computer science. Although I intended to apply my new skills to natural resource management, I was seduced by computer graphics, which was in its infancy. My next job was with the Department of Energy’s Pacific Northwest Laboratory in Richland, Washington. I wrote software for scientists, which was then called scientific programming. We also used the computer to prospect for gold, but we never found any.
I went back to school again, this time, for a master’s in remote sensing. Then I came to work for Goddard.
Is there a connection between your different careers?
My careers are connected through the common theme of computers. I’m excited that some of the imagery I’m currently creating is being used by the wildlife management and forestry community where I initially started.
What inspires you?
For many years, I have had a quote on my wall from Alfred Lord Tennyson’s poem “Ulysses”:
Yet all experience is an arch wherethro’
Gleams that untravell’d world whose margin fades
For ever and forever when I move.
I always want to move forward, to see what is beyond the horizon, to try something new. It’s the way I was born. I’m curious.
What are you searching for at Goddard?
I want to make a practical difference in people’s lives.
How do you make a practical difference?
The thing that is so exciting about my work is that the satellites were originally designed for scientific research, to collect data, but people at Goddard and around the world have found so many other practical uses. In 2000, the western U.S. had a very bad fire season. At that time, the data from our Earth-observing satellites showing the location of the forest fires took weeks to months to be publicly available. At the request of the Forest Service, a team from Goddard and the University of Maryland figured out how to make this data available the same day.
Many other uses have been found for this information including tracking drought and agricultural production, volcanic ash and dust storms.
What is the role of teamwork?
Everything that I do involves teamwork. Thousands of people, in hundreds of disciplines, living all over the world are involved.
What life lesson would you pass along?
You can take anyone’s life story and make a good, entertaining hour-and-a-half movie out of it. Everyone is more interesting than they think.
What would you say to somebody just starting at Goddard?
You never want to be the smartest person in a place because you want to learn from other people. At Goddard, you are surrounded by geniuses. Take advantage of that.
What is first on your bucket list?
I’ve always wanted to go to New Zealand to see the spectacular landscape and wildlife.
This article, compiled by Elizabeth M. Jarrell of NASA Goddard Space Flight Center, was originally published here.