Soaring for Science

NASA's Global Hawk autonomous plane

The newest bird in NASA’s flock — the unmanned Global Hawk — took off at 7 a.m. Pacific time today (April 2) from Dryden Flight Research Center at Edwards Air Force Base in California. The flight is the first airborne checkout of the plane since it was loaded with 11 science instruments for the Global Hawk Pacific (GloPac) mission.

Pilots are also streamlining processes to coordinate the workload while the nearly autonomous plane is flying at altitudes above 60,000 feet (almost twice as high as a commercial airliner). Operators and mission researchers are using the day to make sure all instruments are operating properly while in flight — particularly at the cold temperatures of high altitude — and communicating clearly with the plane and ground controllers. Mission participants expect to begin collecting data when actual GloPac science flights begin over the Pacific Ocean later this month.

GloPac is the Global Hawk’s first scientific mission. Instruments will sample the chemical composition of air in Earth’s two lowest atmospheric layers — the stratosphere and troposphere — and profile the dynamics and meteorology of both. They also will observe the distribution of clouds and aerosol particles. The instruments are operated by scientists and technicians from seven science institutions and are funded by NASA and the National Oceanic and Atmospheric Administration (NOAA).

Paul Newman, the co-mission scientist for GloPac, has been blogging about the mission on Earth Observatory’s “Notes from the Field” site. Here are a few excerpts to whet your appetite…

…There is an old Latin quote: “Maxima omnium virtutum est patientia.” Or “patience is the greatest virtue.” When it comes to mounting science instruments on an aircraft, you need to continually return to that quote…

…During the integration this week, we’ve had to cut holes into the aircraft. I told Chris Naftel, the Global Hawk project manager, that we had to cut some holes into the plane for the Meteorological Measurement System. Chris replied: “I don’t want to hear anything about the holes. It pains me!” In spite of Chris’ pain, the little holes are critical for measuring winds. You’re now asking, what? Little holes? For winds? It’s actually a very slick little measurement that relies on the work of Daniel Bernoulli, a Dutch mathematician who lived in the 1700s…

Read more here …

Working (Very) Remotely

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Bryan Fabbri, Fred Denn, and Bob Arduini typically drive to their jobs at NASA’s Langley Research Center in Hampton, Va. But then there are a few days each month when they take the helicopter instead.

The three scientists are part of the small, hands-on team that maintains a suite of meteorological and climate-observing instruments on the Chesapeake Light, a platform lighthouse 15 miles off the Virginia coast in the Atlantic Ocean.

The instruments record air and sea surface temperature, the amount of sunlight and heat absorbed and reflected by the ocean surface, wind speed, aerosol composition, and on and on. The measurements are made to validate the observations made by the Langley-managed Clouds and the Earth’s Radiant Energy System (CERES).

The CERES satellite instruments have been operating for more than a decade, creating a long-term record of a key driver of Earth’s climate – the balance of incoming and outgoing solar radiation known as the “energy budget.” And the instruments that Fabbri, Denn and Arduini maintain on Chesapeake Light serve to validate the observations CERES makes over the oceans. The project is called COVE (CERES Ocean Validation Experiment) and began along with CERES more than a decade ago.

In a job that usually demands a lot of time crunching data in front of a computer screen, the regular trips to the lighthouse offer a chance for something different. They also highlight a side of science that isn’t often discussed: the grunt work of making sure your instruments are working properly…or haven’t corroded in the humid salt-air…or haven’t blown off the platform with an open-ocean gust. If the sensors aren’t working properly, CERES observations over the ocean would be much more difficult to validate.

It doesn’t hurt that this important work means getting out in the middle of the ocean every now and then.

“You can’t beat that part of it,” Fabbri said. “I get a little stir crazy. I like getting out of the office and out there to work on the instruments. It doesn’t hurt to take the helicopter out.”

— By Patrick Lynch, NASA’s Langley Research Center


Are the Oceans Really Stuffed to the Gills with Carbon Dioxide?

Two months ago, NASA’s Timothy Hall and colleagues published a study that described how they had estimated the amount of manmade carbon dioxide absorbed by the ocean since the start of the industrial era.

Oceans absorb about a third of the carbon dioxide that humans release into the atmosphere, so sorting out a long-term record of carbon uptake is of great interest to climate scientists.

To create their record of the ocean’s uptake of carbon, Hall and Samar Khatiwala, the lead author of the study, devised a clever mathematical technique that proved to be a considerable advance. When Hall’s study appeared in the journal Nature, he assumed the creation of this new long-term, continuous record would headline the news.

But journalists gravitated toward something else entirely: a brief mention that the amount of carbon dioxide absorbed by the ocean seemed to be experiencing, as the researchers put it, “a small decline in the rate of increase in the last few decades.”

“Seas Grow Less Effective at Absorbing Emissions”, one headline trumpeted. Another article compared the world’s oceans to a fish “stuffed to the gills” with carbon dioxide and another reported a “sudden and dramatic drop in the amount of carbon dioxide being absorbed by the sea.

Given the caveats included in the original study, all of this caught Hall slightly off guard. I’ll let Hall, who summarized his reactions to the coverage for What On Earth, pick the story up from here:

My coauthors and I had viewed the ability to estimate the history of ocean uptake of anthropogenic carbon as the highlight of the paper. Previously, observationally-based estimates had only provided a few snapshots in time, and we were proud of the cleverness of our techniques.

It seems clever mathematical techniques, however, don’t make good press releases. Interestingly, coverage of the paper has not focused on the fact that we can estimate the uptake history. Instead it has focused on apparent reductions in the rate of uptake over the last 2 decades.

The figure below shows our estimate of ocean uptake since 1775. The first impression is the rapid increase since 1950, coinciding with the rapid rise in carbon emissions to the atmosphere. The oceans have prevented about 1/3 of anthropogenic carbon emissions from accumulating in the atmosphere. A closer reading of the curve reveals a reduction in the uptake’s rate of increase after about 1980, even while emissions continue to increase.

Scientists have long suspected that ocean carbon uptake would eventually be unable to keep pace with rising emissions. Basic aqueous chemistry tells us that, as dissolved carbon in seawater increases, seawater becomes less able to absorb new carbon. Eventually, the absorption saturates. The slowing down of the increase rate may be an early signal of this saturation.

However, recent changes in uptake were not our focus when we performed the study, and more importantly we did not analyze the statistical significance of the slowdown. We plan further analysis on these trend variations. What we can say is that there are physical reasons to suspect a reduction in the ocean’s capacity to keep pace with increasing carbon emissions, and that there are now strong observational hints for recent reductions.

Hall advises reading this story, which also appeared in Nature. It’s less dramatic and more technical than most of media accounts, but it is a more accurate representation of the paper.

–Adam Voiland, NASA’s Earth Science News Team
   Image Credit: (EPOD/K. Chrisodoulopoulus)

Even in Science,There's More than One Side to Every Story

Every tale has more than one side or perspective. And so it is with NASA, which studies Earth science from different angles – from satellites, from aircraft, and sometimes from the ground. But somehow, no matter how many ways there are to view a place, there’s nothing better than being there.

Case in point: Bryce Canyon National Park in Utah. The interlocking peaks of the canyon rim can top 9,000 feet – high enough that year-round flurries created this snow-capped winter wonderland captured by photographer James Van Gundy. The spectacular oranges, browns, reds, and yellows of the limestone and the unique rain- and frost-carved stone make the park a destination for more than 1.5 million tourists each year.

Those peaks offer breathtaking views of three states and 200 miles of visibility.

In contrast, a Landsat satellite image of the park, taken in 2006, tells a top-side story of streams and rivers and valleys that stretch out like the fingers of a child’s hand print. A host of new colors emerge, not apparent from the ground view. The greens of coniferous forests. The blues of lakes and the Tropic Reservoir.

To see more Web images from Earth Science Picture of the Day, click here.

To see more examples of the Image of the Day from NASA’s Earth Observatory, click here.

– Gretchen Cook-Anderson, NASA’s Earth Science News Team

A Revolutionary Way to Observe Earth


Engineers watch a quarter scale model of a wing-like guidance system that could be used to steer a new type of Earth-observing balloon.  

Science tends to be a conservative profession. Only rarely are “discoveries” made or paradigms upended. And most researchers spend entire careers working toward incremental advances in understanding rather than dreaming up radical new ways to tackle a problem.

So it’s not often that you’ll find the word “revolutionary” in the pages of a peer-reviewed scientific journal. Yet, that’s precisely the word that a group of earth scientists and balloon boosters use liberally in a Bulletin of the American Meteorological Society article describing the experimental balloon platform that NASA-funded scientists and engineers have dreamed up.

They’re called StratoSats and, according to advocates like Warren Wiscombe, a senior scientist at NASA’s Goddard Space Flight Center who studies Earth’s energy budget, the long-duration balloons would cruise on the cusp of space far above airplane traffic. From high in the stratosphere, these super-pressure balloons could collect key data on Earth’s energy budget, climate, magnetic field, and atmospheric water vapor for a tiny fraction of the cost of competing technologies, such as unmanned aerial vehicles or satellites. 

Advocates for StratoSats envision hundreds floating in the stratosphere. Constellations of the balloons could be organized to suit the needs of scientists, from “string of pearl” formations that keep a hurricane constantly in view to more or less uniformly distributed formations – as shown in the simulation below (each yellow dot represents a StratoSat).
 
With the uniform distribution, Wiscombe says, the StratoSats could survey over 99 percent of the atmosphere both vertically and horizontally and cover certain areas near the poles that aren’t
readily detectable by satellite instruments in sun-synchronous orbits. The StratoSats would be able to ride strong zonal winds that would push them around the Earth every 10 to 20 days. 

One nagging drawback of research balloons is that they drift with the winds, which can make it difficult to collect usable data. However, the StratoSats would have a 15-kilometer tether toting a 5-meter wing far below. The wing would function much like the sail of a sailboat, and give scientists the means to keep the balloons on a set course. “Steering a StratoSat is somewhat like steering a cruise ship,” Wiscombe said. “You can’t make sharp turns, but you can achieve a new course within a few days.”

For the last ten years, NASA has been developing ultra-long-duration balloons (ULDB) that aim to study remnants of the early universe. Though some of these stratosphere capable balloons have failed to deploy completely during tests, NASA’s Balloon Program, based at Wallops Flight Facility in Virginia, has carried out a successful 54-day flight of a small Super Pressured Balloon.

Meanwhile, full-scale mechanical prototypes of the StratoSat guidance system have already been built and ground-tested. And NASA-funded engineers have successfully flown one-quarter scale balloon guidance systems (below) from blimps, Wiscombe said.

StratoSat boosters may not have too much longer to wait. According to David Pierce, the Chief of NASA’s Balloon Program, his team is already well on its way to providing the sort of capabilities that StratoSats would require.

“There is still some engineering development that must be accomplished to fully integrate the small super-pressure balloons with the StratoSat sail, but you can expect the smaller super-pressure balloons to be available within the next year for Earth science missions,” he noted. “We are quite confident that StratoSats could do a lot of science at much less cost than orbiting satellites.”

 

Image Information: The second image is an illustration of the StratoSat platform. The third is a map that shows the potential formation of a fleet of StratoSats (each yellow dot represents one StratoSat). All three images were published in the Bulletin of the American Meteorological Society without crediting information. The corresponding author of the paper, which is available here, is Kerry Kock. 

— Adam Voiland, NASA’s Earth Science News Team

Let There be Light

An early morning sun illuminated the light rain over Nevada, Missouri, on May 14, 2009, spraying rays across the sky. Photographer Tommy Hornbeck captured what some viewers may believe to be virga, rain that evaporates before reaching the surface. However, Jim Foster, a hydrologist at NASA’s Goddard Space Flight Center, confirmed with Hornbeck that the rain did indeed dampen the ground and the photographer below. 

The Earth Science Picture of the Day, a web site led by Foster, has received and posted hundreds of captivating images like this one. The site, which marks its 10th anniversary this year, showcases imagery of people who want to share what they observe; photographs that illustrate the marvels and nuances of Earth and our relationship to it. Sun bounces off rain drops. Bright-colored insects take temporary refuge on plant leaves. Ocean mist changes the look of the air where it hangs suspended. You get the idea.  

With support from the Universities Space Research Association and NASA, Foster’s longtime project to educate and engage the public about Earth science has made as many as 3,600 images available online for science enthusiasts.

Want to submit an image to Earth Science Picture of the Day? Click here to learn more. Keep in mind that the images must be your own, and you’ll also need to provide permission for Foster’s team to post them to the site. Good luck!

 — Gretchen Cook-Anderson, NASA’s Earth Science News Team

Sea level isn't really level at all

Our friends at NASA’s Global Climate Change site have a great blog post today that we’d like to share. The message is simple yet critical: rising sea levels do not and will not mean the same thing everywhere on the planet. Oceanographer Josh Willis of the Jet Propulsion Laboratory puts it this way:

Even though it’s sometimes convenient to think of the ocean as a great big bathtub, where turning on the tap at one end raises the water level in the whole tub, real sea level rise doesn’t quite happen that way. To understand why, you first have to realize that ‘sea level’ isn’t really level at all.

There are lots of reasons why the oceans are not level. For example, vast ocean currents like the Gulf Stream in the Atlantic Ocean and the Kuroshio in the Pacific actually reshape the ocean surface, causing it to tilt. As the planet heats up, changes in the prevailing winds (which drive most of these ocean currents) cause changes in the currents, reshaping our ocean and changing local sea level as a result.

Just as global warming does not raise land temperatures evenly, global ocean warming is not the same everywhere around the globe. Some regions of the oceans are heating up faster than others, and because warm water takes up more space than cold water, those regions experience faster sea level rise.

Finally, the water locked away in the great ice sheets of Greenland and Antarctica also shapes the ocean surface. As the ice sheets melt and lose water to the oceans, our entire planet feels the effects. The movement of mass from the ice sheets to the oceans very slightly shifts the direction of Earth’s rotation. This, along with changes in the gravitational pull of the ice sheets on the oceans, will reshape sea levels further still…

Click here to read the full posting from Josh. And be sure to check out the interactive sea level rise viewer. 

— Mike Carlowicz, Earth Science News Team

Can Something Out in Space be Good for Your Health on Earth?

An animation from Morain’s Center, viewable online by local residents, captured a storm crossing southeast Arizona and southwest New Mexico on Jan. 6-8, 2008. This clip, part of a 48-hour dust forecast, centers on the hour of peak dust concentration in the towns of Wilcox and Silver City. Credit: Morain/Earth Data Analysis Center

Stanley Morain is not an asthmatic. But like a lot of other healthy people, his lungs are sensitive to dust in the air in his hometown of Albuquerque. Dust makes him cough. It makes his eyes tear. It makes him pretty miserable.

Morain believed that if he — a healthy individual — is affected by the dust storms common to the American southwest, then hundreds of thousands of asthmatics must be affected far more severely when millions of tiny particles nestle into their respiratory systems.

His career has led him to a spot as director of the Earth Data Analysis Center at the University of New Mexico, where he has encouraged his colleagues and students to follow their hearts in the projects they pursue. He’s set the example by spending 10 years using NASA satellite data to create daily dust forecasts to improve health alerts.

I caught up with Morain a few days before he left for the American Meteorological Society’s annual meeting, where he gave a talk Tuesday about his work. He’s especially excited about decisions by the United Nations and the Joint Board of Geospatial Information Societies to publish his latest dust modeling work this spring.

WhatOnEarth: How did you decide to focus your career on using satellite sensors to improve public health?

Morain: The thought first struck me years ago, before I got my doctorate in biogeography and before I was awarded my first NASA research grant in 1964. I’ve always been fascinated by the geographic aspects of health even when I worked on NASA projects as dissimilar as lunar landers in the 1960s. I found we could combine information technology and modeling to learn more about health problems like heart attacks, Valley Fever, and hantavirus pulmonary syndrome that frequently strikes and kills young, otherwise healthy people within 24 hours.

WhatOnEarth: The Centers for Disease Control estimate 16.4 million adults and 7 million children in the U.S. suffer from asthma. How do your dust alerts help them?

Morain: Well, we’re not yet operational on a large-scale basis. That would take a commercial firm stepping in to make our alerts available nationwide. But, in my own backyard, the alerts are helping asthmatics plan for the worst days. Dust is a real problem here. When people know dust is headed their way, they can adapt their plans to minimize time outdoors or increase the dosage of some asthma medications. We’re making the alerts available, by way of summaries of dust and air quality conditions, to everyone from school nurses to TV news broadcasters to epidemiologists who are concerned about how long-term dust exposure affects the overall population.

WhatOnEarth: How do NASA satellites play into the development of the alerts?

Morain: There are environmental triggers for diseases like asthma. Very fine pollutant particles called aerosols are key examples of such triggers. NASA satellites like Terra and Aqua have instruments that can “see” the path dust takes. When you merge dust modeling information from the satellites with the National Weather Service weather forecasting model, you get a product that tells you when a weather event will bring dust along with it. The product becomes the basis for our daily dust alerts.

Three generations of model improvements for a dust storm across New Mexico and Texas on 15-16 December, 2003 illustrate (left) model performance before and (middle) after satellite data were included; and (right) the same storm modeled by the higher resolution, weather forecasting model Morain’s team uses. Credit: Morain/Earth Data Analysis Center

— Gretchen Cook-Anderson, NASA’s Earth Science News Team

Flying high with NASA's Joanne Simpson

Joanne Simpson, the first woman to earn a PhD in meteorology, didn’t just break into a field where women weren’t welcome. She broke the door down and accumulated a list of scientific achievements that’s rare for any scientist, regardless of gender.

Early in her career, she made the key insight that narrow cumulonimbus clouds–she called them “hot towers” — are the engines that drive tropical circulation and help sustain the eyes of hurricanes. Later, she became one of the first scientists to develop a cloud model, an advance that ultimately sparked a whole new branch of meteorology. She spent decades with NASA, helping to lead the Tropical Rainfall Measurement Mission, a satellite that’s led to key insights about how hurricanes start and how dust affects precipitation. And she was a key proponent for the upcoming Global Precipitation Measurement (GPM), the follow up satellite to TRMM.

No stranger to controversy, she stirred up a scientific furor when she sought to test the validity of her cloud model by experimenting with cloud seeding. Even well into her eighties, Simpson didn’t shy from vigorous debate about the scientific basis of global warming.

In March, at the age of 86, Simpson passed away in Washington, D.C. In a recent interview with the Discovery Channel, a producer asked her what was the most fascinating thing about studying the atmosphere. “In my case, it’s the clouds,” she said without hesitation. “There are some beautiful ones out there right now,” she said while gesturing toward the window.

In tribute to Simpson’s efforts to understand clouds, we’ve chosen four of our favorite cloud images from a series of images that Simpson donated to the NOAA Photo Library and likely took. The photographs were taken from NASA’s DC-8 during the TOGA-COARE project in the 1990s.

Joanne Simpson Portrait Information: Illustration by Martin Mueller of NRC and NASA GSFC via NASA’s Earth Observatory.


Puffy fair weather cumulus clouds and hints of reefs are visible below the right wing of NASA’s DC-8. Credit: NOAA Photo Library/Dr. Joanne Simpson Collection


A towering example of a showering anvil cloud roils over the Pacific Ocean. Credit: NOAA Photo Library/Dr. Joanne Simpson Collection


Dusk falls over the Pacific Ocean with a large cumulonimbus cloud in the distance. Credit: NOAA Photo Library/Dr. Joanne Simpson Collection

— Adam Voiland, NASA’s Earth Science News Team