Monthly Archives: February 2017

Bowing Before the Wind

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View of the cockpit of the DC-8 in flight. Credit: NASA/Michael Prather

View of the DC-8 cockpit in flight. Credit: NASA/Michael Prather

by Ellen Gray / CHRISTCHURCH, NEW ZEALAND /

The Atmospheric Tomography, or ATom, mission’s world survey of the atmosphere can’t fly the order of its locations in reverse.

Its flight plan begins with traveling from California to Alaska and the North Pole before flying south down the center of the Pacific Ocean by way of Hawaii to New Zealand. From New Zealand, they cross east to Chile before ascending north up the Atlantic to Greenland.

It’s this southernmost crossing from Christchurch, New Zealand, to Punta Arenas, Chile, that’s a one-way street.

“The plane can’t make it from Punta Arenas to New Zealand because the winds are too strong,” said Róisín Commane, an atmospheric scientist at Harvard University who is part of the ATom mission.

The winds that travel from west to east above the Southern Ocean around Antarctica are among the strongest in the world. With few land masses to slow them down, they blow unimpeded.

Leg #6 for ATom is from Christchurch, New Zealand to Punta Arenas, Chile, flying the gusty Southern Ocean that encircles Antarctica. Credit: NASA

Leg #6 for ATom is from Christchurch, New Zealand to Punta Arenas, Chile, flying the gusty Southern Ocean that encircles Antarctica. Credit: NASA

Those strong winds led to complications for the ATom team as they were preparing for their Feb. 10 flight from Christchurch to Punta Arenas. In a small hotel conference room around a cell phone and computers sharing a screen from weather forecasters back at NASA’s Goddard Space Flight Center, Steve Wofsy, ATom’s project scientist, peered at a circular weather system at the end of their flight path. The system created an eddy in the prevailing west-east wind that coincided with their arrival in Punta Arenas. The concern around the table was that strong winds would be blowing perpendicular to the runway when the plane was trying to land, potentially pushing it sideways.

The DC-8 can handle this kind of crosswind up to about 25 knots, or 28 miles per hour. Above that, for safety the pilots would have to divert to a back-up landing site. The closest in Chile was in the range of the same weather system—and likely to have the same crosswinds. The other was in Argentina two hours away, which would require fuel reserves that would take away from the number of profiles of the atmosphere they could do on the crossing, one of the main reasons for this mission. It would also require a second flight to get the team back to Punta Arenas the day after the system passed.

Project Scientist Steve Wofsy getting ready to board NASA's DC-8 at 5:30am. Credit: NASA

Project Scientist Steve Wofsy getting ready to board NASA’s DC-8 at 5:30am. Credit: NASA

It was a disruption that Wofsy didn’t want to take on after an already difficult 10-hour flight with an 8-hour time change. From their experience on ATom’s first deployment in 2016, they knew from experience that the jet lag on this leg of the trip was brutal.

After three mornings watching the updated forecasts and NASA ground personnel talking with local weather forecasters in Punta Arenas, the morning of their scheduled departure from New Zealand arrived. The forecast hadn’t changed much. There was a 20-25 percent chance that the winds would be too strong and the plane would have to divert, said Wofsy. After a last early morning meeting with the pilots and forecasters, they made the decision to scrub the flight and wait a day for the storm to pass.

By the next day the system had indeed moved on, and the runway in Chile was safe for landing. The ATom team departed after their extra day in Christchurch and with. an adjusted schedule that would give them one less day in Punta Arenas. But on a mission dependent on good weather, that’s the way the wind blows.

 

Grit Factor and Teamwork

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Noah Walcutt, University of Rhode Island, inspects mangled sediment traps recovered from the first sampling site. Shark damage was later confirmed. Credit: University of Rhode Island/Melissa Omand

Noah Walcutt, University of Rhode Island, inspects mangled sediment traps recovered from the first sampling site. Shark damage was later confirmed. Credit: University of Rhode Island/Melissa Omand

by Stephanie Schollaert Uz, North Pacific Ocean

Shark attack. Rough weather. Intermittent technology. These are just a few of the challenges of shipboard research on the R/V Falkor. Yet the science continues with unbelievable tenacity on the 28-day Sea to Space Particle Investigation.

When Melissa Omand’s sediment traps, deployed to measure sinking particles, were returned from the sea bent and broken at the end of the first 4-day sampling site, she was briefly discouraged. She wondered whether her experiment to collect data with an iPhone was jeopardizing established collection methods. The iPhone housing is big and heavy and could have swung into the other three sediment-collecting tubes and smashed them.

Then one of the line handlers showed me a shard that got stuck in his finger—later revealed under the microscope of the resident taxonomist as part of a shark’s tooth and confirmed by shark experts ashore. Shark bite marks were also noticed on the more rugged, indefatigable wire walker. Several ship’s crew volunteered their time and talent to rebuild the sediment traps stronger and better. After that, the refurbished sediment traps survived deployment and collected stunning data at the next station.

Hemispheric view by Suomi-NPP VIIRS on Feb 9, 2017 in true color. Clouds and atmospheric particles are white; ocean is blue. The ship’s track is shown in the red line. Station M is our last sampling site. Credit: NASA/Norman Kuring

Hemispheric view by Suomi-NPP VIIRS on Feb 9, 2017 in true color. Clouds and atmospheric particles are white; ocean is blue. The ship’s track is shown in the red line. Station M is our last sampling site. Credit: NASA/Norman Kuring

As those on the U.S. West Coast are well aware, the past month has seen a constant procession of low pressure weather systems across the Pacific. One of the main goals of this cruise is to collect data that can later be used to tune ocean color satellite measurements. Rough weather at sea is more than an inconvenience: it makes it unsafe to use the light sensor we put in the water to compare to satellite measurements. Persistent clouds obscure satellite coverage of our area—making match-ups between in-water measurements and satellite data impossible anyway.

To avoid the bad weather and high seas we would have encountered on our original planned cruise track nearly straight north, the ship’s captain worked closely with the chief scientist to revise our plans and head east.

As we started work at our second site, however, we lost all internet. The ship’s IT coordinator found a broken satellite antenna that caused the internet not to work during certain ship headings. Again, the captain worked closely with the science party to modify the course track for on-site sampling that would also permit internet connectivity.

In spite of everyone’s best attempts to maximize our bandwidth, we still experienced repeated drop-outs during the NASA Earth Facebook live event we conducted from the ship on Feb 6. It felt like the movie Groundhog Day, with repeated re-introductions as we reconnected to the event again and again. Thankfully, we had help from NASA JPL colleagues ashore and an engaged audience who remained online and sent excellent questions and follow-up questions afterward.

Another challenge was finding and recovering the sediment traps from the second sampling site as it was issuing a weak and intermittent GPS signal between large waves. All hands on deck kept look-out during the wind and rain until its little orange top was spotted. The crew skillfully maneuvered the ship along-side and caught the instrument’s yellow handling line to lift it back aboard with a crane.

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In heavy seas, Philipp Günther, Falkor’s chief officer, retrieves sediment traps that were deployed around 150 meters deep to collect sinking ocean particles. Credit: NASA/Stephanie Schollaert Uz

Over and over again during this expedition, we experience challenges that are solved through teamwork between the science party and ship’s crew. The novel data being collected here would not be possible without this persistence and collaboration.

Participating in this field campaign to improve the quality of ocean color satellite measurements are five of us from NASA Goddard’s Ocean Color group, plus NASA- and NSF-funded scientists from other organizations. In addition to improving current satellite measurements, data collected here will assist in the development of algorithms for NASA’s first hyper spectral satellite, Plankton, Aerosol, Cloud, ocean Ecosystem (PACE), scheduled to launch in 2022.

R/V Falkor ship-time is generously provided by the Schmidt Ocean Institute, a philanthropic organization led by Google CEO Eric Schmidt and his wife, Wendy Schmidt. For #Sea2Space cruise track and updates: https://schmidtocean.org/cruise/sea-space-particle-investigation/

Super Bowl Sunday in the Atmosphere’s Mixing Bowl

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Mission manager Tim Moes and Operations Engineer Matt Berry support the Falcons aboard NASA's DC-8 flying laboratory on the ATom flight leg from Fiji to New Zealand, Feb. 6, 2017. Credit: NASA/Ellen Gray

Mission manager Tim Moes and Operations Engineer Matt Berry support the Falcons aboard NASA’s DC-8 flying laboratory on the ATom flight leg from Fiji to New Zealand on Feb. 6, 2017. Credit: NASA

by Ellen Gray / CHRISTCHURCH, NEW ZEALAND /

Good communication is key to keeping the 44 scientists and aircrew happy on NASA’s DC-8 aircraft. The team is in close quarters for a month-long journey around the world to survey the atmosphere on NASA’s Atmospheric Tomography, or ATom, mission. On the plane they keep in touch with each other via headset and with scientists supporting the mission back home via satellite chat room.

But on Feb. 6, on the other side of the International Date Line (Feb. 5 in the United States), as the team made their transit from Nadi, Fiji, to Christchurch, New Zealand, one topic was forbidden—updates on the Super Bowl.

Róisín Commane, an atmospheric scientist and Patriots fan at Harvard University in Cambridge, Massachusetts, did a rough poll. Half the people on the plane followed football, and they were nearly evenly split between Patriots and Falcons fans. And all of them wanted to see the game unspoiled.

On the ground in Christchurch, Quincy Allison, the logistics coordinator with NASA’s Earth Science Project Office out of Ames Research Center, had already arranged with hotel staff to record the game and play it in a conference room after the ATom team got in that evening.

Meanwhile, during their Super Bowl news blackout, the team continued to make measurements to better understand our atmosphere. The ATom mission is the most comprehensive survey of the atmosphere to date, with 22 science instruments measuring more than 200 gases and air particles and an itinerary that has it tracing from the North Pole down the Pacific Ocean to Christchurch, then cutting across to the southern tip of Chile, then traveling back up the center of the Atlantic to Greenland and the Arctic. Along the way they’re island hopping between flights, with only a day or two on the ground before moving on. Christchurch, at about halfway, is their longest stopover at three days and also their major resupply point.

Gathering data to help understand the atmospheric chemistry that drives air quality around the globe is worth the grueling pace for Commane, who likened the atmosphere to a different kind of bowl.

Atmospheric chemist Róisín Commane on the stairs of DC-8. Air intake valves stubble the outside of the plane to draw air into the instruments while in flight. Nadi, Fiji, Feb 6 2017. Credit: NASA

Atmospheric chemist Róisín Commane on the stairs of NASA’s DC-8. Air intake valves stubble the outside of the plane to draw air into the instruments while in flight. Nadi, Fiji, Feb 6 2017. Credit: NASA

“It’s like a mixing bowl,” she said. The air over the oceans is theoretically clean, but winds, especially in the Northern Hemisphere, carry pollution from industry or fires from continent to continent. Looking at some of their data in the middle of the Pacific Ocean, she said they saw signs of fires. “I said, ‘Where did this come from?’” she recalled. The weather and wind models said Africa, where agricultural fires are common in the summer and fall. “That’s on the opposite side of the world.”

Clouds above the Pacific Ocean on the way from Fiji to New Zealand. Feb 6, 2017. Credit: NASA

Clouds above the Pacific Ocean on the way from Fiji to New Zealand on Feb 6, 2017. Credit: NASA

Air doesn’t stay in one place, and as it travels, the hundreds of different gases and particles that make up the air encounter new ones generated in different areas, and they chemically react with each other. Some of the pollutants are scrubbed out of the atmosphere this way, disappearing or transformed into new gases. These are the processes that the ATom science team is interested in learning more about, in addition to just knowing how much pollution is really out there over the ocean.

A lack of measurements gives people a false sense that everything is okay, said Commane. “We think we don’t need to do better,” she said. Poor air quality is something she doesn’t want anyone to live with, whether it’s generated at home or is a wind-driven import. “You might not always be able to see it, but when you’re in it you can feel it. You can taste it.”