Plumes Go the Distance

True color satellite image of Canada and the northern United States on July 23, 2019. Fires in northern Alberta (red dots in top left) produced smoke that traveled to the Great Lakes (bottom right) over the course of a few days. Credit: NASA EOSDIS / Worldview
True color satellite image of Canada and the northern United States on July 23, 2019. Fires in northern Alberta (red dots in top left) produced smoke that traveled to the Great Lakes (bottom right) over the course of a few days. Credit: NASA EOSDIS / Worldview

by Ellen Gray / BOISE, IDAHO/

From Alberta, Canada, to Michigan, USA. That’s how far the plumes of smoke traveled in a few short days, from July 21 to July 24. Smoke from wildfires has staying power.

Laura Thapa, a graduate student at the University of California Los Angeles and member of the FIREX-AQ forecasting team, has been monitoring the smoke from the northern Alberta fires over the last few days. She and her team first took notice of the plume on July 21, when its leading edge had already traversed half of the approximately 2000-mile journey to the Great Lakes by July 24.

Tracing a plumes’ journey accomplishes two main goals for FIREX-AQ. “It lets us verify the forecast models,” Laura said. The forecast team wants to improve and fine tune a number of smoke transport models that use weather and other data to project where smoke plumes end up.

In particular, scientists want to know where the fine particulate aerosols called PM 2.5 go. The microscopic particles are one of the biggest health hazards associated with fires. When breathed in, they can lodge deep in the lungs, causing irritation and coughing. Long term exposure has been linked to higher rates of respiratory and heart problems.

“I have asthma, so that’s my vested interest,” Laura said. It’s also the vested interest of the U.S. Forest Service, which leads the interagency Wildland Fire Air Quality Response Program, and the Environmental Protection Agency that closely monitors PM 2.5 and tries to limit exposure to communities downwind of fires.

The other goal tracking plumes serves is much more practical during the campaign. As the fire season progresses, background smoke from fires-in-progress may be present in the air when a new fire starts and a new plume develops. Keeping track of plumes as they travel helps tease out what fires contributed to the smoke the science team is measuring in the DC-8.

“Understanding the transport is important for seeing what’s going on,” Laura said.

The DC-8 Goes the Distance, too

The DC-8 takes off from Boise, Idaho, for a science flight on July 25, 2019. Credit: NASA
The DC-8 takes off from Boise, Idaho, for a science flight on July 25, 2019. Credit: NASA

The FIREX-AQ team will be in Boise through August 18, but for the Communications team our coverage is at an end. For now.

After Boise, the DC-8, Twin Otters, Mobile Labs, and everything else FIREX-AQ brought with them to Boise will travel to Salina, Kansas, to study prescribed agricultural fires which have different fuels and emissions.

Stay tuned.

 

Join us on @NASAExpeditions Twitter and NASA Expeditions Facebook for more from FIREX-AQ in Boise. Our coverage in Salina will continue on @NASAEarth and the NASA Earth Facebook page.

Fire Weather, Pyro Weather

True color satellite image from MODIS on July 28, 2019. The red dots are fires detected by the MODIS and VIIRS instruments. In southwest Oregon, the smoke plume from the Milepost 97 fire is visible. Credit: NASA EOSDIS/ Worldview
True color satellite image from MODIS on July 28, 2019, of Washington, Oregon and Idaho. The red dots are fires detected by the MODIS and VIIRS instruments. In southwest Oregon, the smoke plume from the Milepost 97 Fire is visible. The red dot in central Idaho is the Shady Fire. Credit: NASA EOSDIS / Worldview

by Ellen Gray / BOISE, IDAHO/

Each morning Amber Soja gets up at 5:00 a.m. to check the fire weather. She’s an associate scientist from the National Institute of Aerospace based at NASA’s Langley Research Center in Virginia, one of the lead forecasters for FIREX-AQ with one of the most important jobs: distilling the information from the National Weather Service, the National Interagency Fire Center, and other satellite and model info into a short list of fires for the DC-8 to visit the next day. All by 8 a.m.

Understanding fire weather is a big part of the job. Fire weather is the term used to describe weather conditions favorable for fires to start or burn, a mixture of high temperature, low humidity, zero to low rainfall, and high winds.

“Fire weather is the potential to have the fire behavior that we want to see,” Amber said. Hot, dry and windy conditions build over the course of a day’s worth of sunshine, so that where fire weather conditions are present in the morning, fires in the same area are likely to become active in the late afternoon. And for the FIREX-AQ science team, active usually means a smoke plume to fly through.

The National Weather Service puts out daily maps of where they forecast fire weather to be elevated. This map came out on July 28, 2019. Credit: NOAA/ NWS
The National Weather Service puts out daily maps of where they forecast fire weather to be elevated. This map came out on July 28, 2019. Credit: NOAA/ NWS

At 10:00 a.m., Amber presents her team’s short list of fires to the science team at the daily morning briefing. This is the meeting where decisions are made about where and when to fly the DC-8. In a neat table projected on the wall, the fire short-list also takes into account the types of fuel on the ground – the second major ingredient for wildfires, and one that can change the chemistry of the plume whether its grassland or timber – as well as location, size, and what action is being taken to monitor and fight the fire, among other considerations.

While Amber is putting together the fire outlook, David Peterson from the U.S. Naval Research Laboratory in Monterey, California, is working with a team of meteorologists and forecasters to monitor and forecast weather systems. It’s a slightly amped up version of a local weather newscast, and includes current conditions and outlooks for high and low pressure systems, moisture, and cloudiness that could hamper the DC-8. By 9:00 a.m. they’re analyzing their model results, and at the 10 a.m. briefing, David shares the forecast with the science team.

The forecasting team meets early everyday to look at upcoming fire and weather conditions. July 28, 2019. Credit: NASA
The forecasting team meets early everyday to look at upcoming fire and weather conditions. July 28, 2019. Credit: NASA

He’s also on the lookout for the potential for a different type of weather – weather generated by the fires themselves.

“A fire is a heat source. It’s creating a strong updraft,” David said. The smoky air above a large, hot fire shoots upward like going up a chimney, and in the void left behind, more air is sucked in from the sides, which gets heated and lofted. When this fire-generated circulation lofts the smoke high enough, from 15,000 to 30,000 feet, and there’s moisture at the higher altitudes, pyrocumulonimbus clouds can form – also known as smoke-infused thunderstorms.

These billowing, smoke-polluted storms don’t really produce rain, but lightning strikes are possible. They can also, in some cases, loft a large smoke plume into the upper atmosphere (stratosphere), where it can circulate around the globe, similar to the impact from a volcanic eruption.

With each daily forecast, David is on the lookout for conditions that might produce pyro-clouds and thunderstorms. In the coming week, the weather over the Shady Fire looks promising, but only time – and a little luck – will tell.

UPDATE Aug 13, 2019: The DC-8 flew through a pyrocumulous cloud on August 8 generated by a fire in eastern Washington. David got to sit in the cockpit and see the cloud from the air. See the stunning pictures and read more about it at NASA’s Earth Observatory Image of the Day.

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A Visit to the National Interagency Fire Center

The National Interagency Fire Center in Boise, Idaho, is the nerve center for fire fighting operations in the United States. Credit: NASA
The National Interagency Fire Center in Boise, Idaho, is the nerve center for firefighting operations in the United States. Credit: NASA

by Ellen Gray / BOISE, IDAHO/

The FIREX-AQ campaign is flying out of Boise, Idaho. The choice of location was no accident. Boise is also home to the National Interagency Fire Center (NIFC), the nerve center of all major firefighting operations for the United States. Earlier this week, we took a tour.

“NIFC is not an organization, it’s a place. Each big bureau dealing with fires has people here,” said Kari Cobb, our tour guide with the Bureau of Land Management in the Department of Interior that hosts the center.

In addition to the Bureau of Land Management, the agencies working together to put out major wildfires, support the crews in the field and assist with other disasters include the National Association of State Foresters, the USDA Forest Service, the Department of Defense, the National Oceanic and Atmospheric Administration, the Bureau of Indian Affairs, the National Park Service, the United States Fire Administration, and the U.S. Fish and Wildlife Service.

The center is located next to the Boise Airport – across from the Idaho Air National Guard where the DC-8 is stationed for FIREX-AQ. Airport access is essential for the helicopters and planes used to deliver crews and supplies to firefighting teams in the field, and also for reconnaissance planes that survey active fires with infrared instruments to detect hotspots hidden by smoke plumes.

The Radio Cache

The NIFC Radio Cache has a team of technicians that check and refurbish every single handheld radio and repeater. They will replace faulty parts down to the transistor to extend the radios' lifetimes. Credit: NASA
The NIFC Radio Cache has a team of technicians that check and refurbish every single handheld radio and repeater. They will replace faulty parts down to the transistor to extend the radios’ lifetimes. Credit: NASA

In order to coordinate, you need to be able to communicate. NIFC’s Radio Cache ensures that’s possible. They manage, repair and refurbish the 11,000 handheld radios and radio repeaters that get delivered to firefighters in the field. They deliver the equipment in kits that are already pre-programmed to be ready to plug-and-play as soon as they arrive. While all the radios are ultimately managed and dispatched from Boise, they pre-position equipment closer to likely fire activity and other disaster-prone areas.

The Great Basin Cache

NIFC's Great Basin Cache supplies all of a firefighter's gear except for their boots. Credit: NASA
NIFC’s Great Basin Cache supplies all of a firefighter’s gear except for their boots. Credit: NASA

When you’ve got people fighting fires for weeks on end, you need a place for them to sleep, eat and manage day-to-day operations. Kari described the giant warehouse that makes up the Great Basin Cache as the “Costco” of wildland fire management. It’s the largest of the 16 caches set up in different parts of the country, and has everything needed for the Incident Command Posts, from tents, sleeping bags, tables, and coffee, to firefighters’ personal protective gear, and the shovels, Pulaskis (axe plus flat-head scraper), MCleods (a type of rake) and combi-tools (with a shovel and pick head) they use to clear vegetation and dig fire breaks.

Smokejumpers

Smokejumpers wear Kevlar jump suits to avoid punctures from rocks and branches when they land in rough terrain. They also carry extra rope for getting out of trees. Credit: NASA
Smokejumpers wear Kevlar jump suits to avoid punctures from rocks and branches when they land in rough terrain. They also carry extra rope for getting out of trees. Credit: NASA

There are plenty of people willing to jump out of perfectly good airplanes, but not nearly as many willing to jump out of a plane next to a wildfire. In the United States, there are 450 in fact, and 80 to 85 of these smokejumpers are stationed out of Boise at any given time. Currently most of the Boise smokejumpers are at out-stations, located across the West to be closer to fire-prone areas.

They’re delivered to remote fires by Twin Otter aircraft and jump from 3000 feet in special gear made of Kevlar that each smokejumper has made themselves (they’re required to know how to sew and use a sewing machine.) They jump with one main parachute, a reserve parachute and two days of personal gear. Once they’re on the ground, the plane drops supply kits for two firefighters for two days. Their regular firefighting gear is on under their jump suit, which they stash before getting to work.  Once they’ve done their initial assessment and work at the fire site, relaying info back to base, they hike out.

National Weather Service Boise

The National Weather Service Boise station forecasts fire weather and monitor lightning strikes which can cause fires. Credit: NASA
The National Weather Service Boise station forecasts fire weather and monitors lightning strikes which can cause fires. Credit: NASA

Weather conditions – wind, humidity, rain and temperature – are fundamental to understanding what a fire is doing and where it will go next. The National Weather Service station in Boise monitors and forecasts weather for southwest Idaho and western Oregon. They’re staffed 24 hours a day, and use satellite imagery and models to forecast not only the weather, but fire weather – conditions favorable for burning. They also track lightning strikes, which are one of the main causes of wildfires in the region.

National Interagency Coordination Center

NIFC's National Interagency Coordination Center supports fire fighting efforts across the country. Credit: NASA
NIFC’s National Interagency Coordination Center supports firefighting efforts across the country. Credit: NIFC

Putting it all together is the National Interagency Coordination Center – effectively a national dispatch center, which manages the support resources and sends them into the field where they are needed. Fire management begins locally, at the town or county level. When their capacity for fighting a wildfire is exceeded, they go to their regional support center, one of eleven spread throughout the country. When their resources are exceeded, that’s when they call on the National Interagency Coordination Center in Boise – who then pulls crews from other regions, and sometimes Canada, Australia and New Zealand, to help put out the fires. They also supply information, helicopters and water tankers, and handle getting food and showers in place at the Incident Command Post.

 

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The Shady Fire, a Deviation From Plan

The Shady Fire smoke plume seen from the DC-8 on Thursday, July 25. Credit: Bernadett Weinzierl, University of Vienna
The Shady Fire smoke plume seen from the DC-8 on Thursday, July 25, 2019. Credit: Bernadett Weinzierl, University of Vienna

By Ellen Gray / BOISE, IDAHO/

Thursday, July 25

“It’s nice to have a flight plan to deviate from,” said DC-8 pilot Tim Vest at the debrief on Thursday night. It was just after 10 p.m. and the DC-8 had just returned from a 6-hour flight over a fire they weren’t planning on visiting.

The original plan for the afternoon was to fly to eastern Washington State, where several fires were burning in clear skies. But wildfires are tricky things. That morning during flight planning, the Shady Fire, less than 30 minutes away by air in the Salmon-Challis National Forest, didn’t look like it was going to generate an impressive smoke plume. But a half hour before take-off at 4 p.m., after the instrument teams were aboard and the DC-8’s doors were closed, the scientists staying behind to monitor the flight from the ground pulled down new satellite images.

“They said, take a look at the Shady Fire once you’re in the air,” said Carsten Warneke from the University of Colorado working at the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory in Boulder, Colorado. He’s one of FIREX-AQ‘s project scientists and was sitting in the DC-8’s cockpit jump seat as Thursday’s flight mission scientist.

Flying north on their original plan to the Washington fires, Carsten  – and everyone else with an eastern-facing seat – looked out the window. Shady’s smoke plume was big and billowing. The hot and dry conditions of the late afternoon had invigorated the fire and helped to loft its smoke thousands of feet into the atmosphere.

The Shady Fire seen from the ground in the Salmon-Challis National Forest on Friday, June 26. Credit: U.S. Forest Service
The Shady Fire seen from the ground in the Salmon-Challis National Forest on Friday, June 26, 2019. Credit: U.S. Forest Service

“It was very exciting,” said Carsten. Measuring smoke was why the science team was flying. “But it was also a surprise. We had a completely different flight plan, but then there was that plume.”

So, less than half an hour after take-off, the flight plan changed.

Fortunately, the Shady Fire had been the second fire on the list for the previous day’s flight, although they’d only made one pass over its then-low-lying plume. Tim Vest and his co-pilot, Dave Fedors, both from NASA’s Armstrong Flight Research Center, were able to use the that plan once they redirected.

Aboard the Aboard the DC-8, monitors show Wednesday's flight plan in black overlaid by the actual path of the plane in red. On the left you can see the sharp right turn from diverting from the original plan. At this point in the flight they'd completed one sequence of the lawnmower sampling path. Credit: NASADC-8, monitors show Wednesday's flight plan in black overlaid by the actual path of the plane in red. At this point in the flight they'd completed one sequence of the lawnmower sampling path. Credit: NASA
Aboard the DC-8, monitors show Wednesday’s flight plan in black overlaid by the actual path of the plane in red. On the left you can see the sharp right turn from diverting from the original plan. At this point in the flight they’d completed one sequence of the lawnmower sampling path. July 25, 2019. Credit: NASA

Flying over a wilderness area was a huge advantage. With no other air traffic, aside from a pass from a plane gathering a hotspot survey for the U.S. Forest Service, the pilots had a lot of room to work with. They guided the plane in a series of maneuvers that began with flying above the plume at 15,000 feet to gather data from the remote sensing instruments. Then they cruised to a lower altitude of about 5,000 feet above the terrain and flew through the plume in a pattern called “the lawnmower” that cut north-south back and forth across the eastward-stretching plume. By the time they’d completed the first pass, the plume had been spread by winds farther east, and the smoke gases had been reacting in the atmosphere for about two and a half hours since they began. So they went back to the source and “mowed” it again, and then did a third pass east to west through the length of the plume. By the time they headed back to Boise, the plume had extended to the Wyoming border.

Flying through the plume, it was surprisingly dark, said Carsten. During each lawnmower pass, they had zero visibility where the smoke was thickest, closer toward the Shady Fire’s vertical plume (which they didn’t fly through because it was too hot and turbulent). The light that filtered in, especially as they moved toward the less dense eastern end, was yellowish-brown that snapped to clear once they exited the smoke on each perpendicular pass.

“It was smelly, too,” said Carsten. “Not as bad as I was expecting but it still smelled like smoke.”

The view from the jump seat right after take-off. From here, Carsten as mission scientist can easily communicate with the pilots and flight engineer in the cockpit. Credit: NASA
The view from the jump seat right after take-off. From here, Carsten as mission scientist can easily communicate with the pilots and flight engineer in the cockpit. July 25, 2019. Credit: NASA

As mission scientist, Carsten was in charge of meeting the science goals of the flight. This largely meant he was frequently switching between chatting with the ground team who had the updating satellite imagery and two different headsets on the plane: one on the science team channel where requests for adjustments were flying thick and fast, and one on the pilot channel to figure out what was possible and safe for the aircraft. Balancing all that information, Carsten directed the details of the flight to try to get the best measurements for everyone.

“Then after we turned at the end of each pass, I would call out on the science channel ‘Get ready we’re measuring smoke in 30 seconds,'” he said.

A close up of the Shady Fire's smoke plume during sampling on July 25, 2019. Credit: Bernadett Weinzierl, University of Vienna
A close up of the Shady Fire’s smoke plume during sampling on July 25, 2019. Credit: Bernadett Weinzierl, University of Vienna

The Shady Fire started from a lightning strike on July 10 at about 6 p.m. Since it’s in a wilderness area far from populated areas, the U.S. Forest Service has closed nearby roads and trails and is monitoring it, but otherwise letting it burn for now – with the exception of protecting specific buildings and assets in the area. So far it has burned more than 2600 acres of primarily subalpine fir and lodgepole pine trees.

For the FIREX-AQ science team the Shady Fire is exactly what they’re looking for to study smoke dynamics in the atmosphere – what are the gases and airborne particles in plumes and how do they evolve as they age and spread downwind.

“We’re measuring everything a non-chemist knows about and then 500 more chemicals,” said Carsten. The DC-8 is loaded up with instruments and more than 30 scientists to run them during flight. Among the gases they’re measuring are carbon dioxide, carbon monoxide, and nitrogen oxides, as well as particulate aerosols including soot and black carbon.

The interior of the DC-8 has instruments where seats would be on a commercial plane. They suck smoke inside through inlets and tubing that connect to the instruments. July 25, 2019. Credit: NASA
The interior of the DC-8 has instruments where seats would be on a commercial plane. They suck smoke inside through inlets and tubing that connect to the instruments. July 25, 2019. Credit: NASA

They’re also measuring chemicals formed in the plume, such as ozone. Ozone near Earth’s surface is a pollutant and health hazard that the Environmental Protection Agency monitors to evaluate air quality. It forms from a reaction of nitrogen oxides with volatile organic compounds (both emitted in large amounts from the fire) in the presence sunlight (that often forgotten ingredient in atmospheric chemistry.) During Thursday’s flight, the team saw ozone forming in the plume.

The science team’s excitement was palpable when they returned, and the instrument teams spent Friday getting a first crack at their data. Their deviation from the plan had been a huge success.

At the Friday morning briefing, when the team was taking a look at their options in Washington and Oregon for Saturday’s proposed flight, project scientist Jim Crawford from NASA Langley said, “Put together a flight plan for each of them.”

“And,” said Jack Dibb, project scientist from University of New Hampshire, “have a plan for Shady in our back-pocket.”

 

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Laying Down with Smoke in the Valley, an Unexpected Camping Trip

Bruce Anderson and the NASA Langley Mobile Lab in a valley near Stanley, Idaho. July 24, 2019.
Bruce Anderson and the NASA Langley Mobile Lab in a valley near Stanley, Idaho. July 24, 2019. Credit: NASA

By Ellen Gray / NEAR STANLEY, IDAHO /

Wednesday, July 24

We were ready to fly. We’d heard Tuesday evening that there were two seats open on the DC-8 for the communications team on Wednesday, but as often happens in the field, plans change. For the first science flight, requests for extra seats from the instrument teams came in after the morning briefing. Safety first, science second, and communications third. But rolling with the change of plans opens up new opportunities, and ours was leaving at 2 p.m.

Out in the hangar parking lot, the NASA Langley Mobile Laboratory was getting ready to head into the Idaho wilderness. The van is big, boxy, and white. Unmarked, it looks like the kind of van movie FBI agents use for surveillance, but inside the equipment is designed to watch the sky. Specifically, the small team of five is looking at trace gases and aerosols from smoke plumes that will sink to valley floors during the night when temperatures cool.

The Langley Mobile Lab is one of two that will be deployed to take ground-level measurements during the FIREX-AQ field campaign. Ideally, the team parks the van downwind from a blazing fire whose smoke flows over the van site, said Bruce Anderson, the principle investigator for the NASA Langley Aerosol Research Group Experiment that runs the van. From their parking spot, they’ll watch the emissions evolve as the fire goes from hot and intense to smoldering and from hot daytime temperatures to cold nights and back to day.

With about two hours’ notice, Bruce graciously agreed to let us tag along. “Do you have camping gear?” he asked.

I had a sleeping bag I hadn’t expected to use during FIREX-AQ. None of us had meant to sleep anywhere but at our hotel. But this trip was too good to pass up. We reassured Bruce that we’d make do.

Landscape Shaped By Fire

Burned trees and recovering undergrowth at varying stages make up the National Forests along Highway 21 in Idaho. July 24, 2019. Credit: NASA
Burned trees and recovering undergrowth at varying stages make up the National Forests along Highway 21 in Idaho. July 24, 2019. Credit: NASA

Because of the van’s size, Bruce drove the long way on the major highways to Stanley, Idaho, a town in the middle of the Sawtooth National Recreational Area. We took the more direct and windier Highway 21 through the Boise and Challis National Forests.

Boise is located on a plain, with brown hills dotted by shrubs dominating the landscape. As we drove northeast, the hills gave way to forests of lodgepole pines and subalpine firs. Fires’ mark on the landscape soon became clear.

Fire is part of the ecosystem in the western U.S., leaving behind ghostly trees and charred soil that will grow new life. July 24, 2019. Credit: NASA
Fire is part of the ecosystem in the western U.S., leaving behind ghostly trees and charred soil that will grow new life. July 24, 2019. Credit: NASA

Amid the green trees of the forest, we passed entire slopes of ghostly trees, burned pale and dead but still standing with bare branches. On some slopes, grasses and scrub had regrown. On others, smaller baby trees made up the understory. On still more, the burned ghost trees were interspersed with healthy green trees at the same height – likely grown to maturity after the fire. The marks of past fires were everywhere – and then we passed the blackened char of recently contained fires.

The Canyon Fire and the Vader Fire were both near the road, and while the flames were out where and when we saw them – each fire was 75-80% contained at that point – smoke was smoldering from a few hotspots on the ground. The Canyon Fire started from a lightning strike on July 14, a common cause for wildland fires. The Vader Fire’s cause is still unknown.

Nighttime Science

Our campsite near Stanley, Idaho, was in the middle of a long and wide valley, framed by mountains. July 24, 2019. Credit: NASA
Sunrise at our campsite near Stanley, Idaho. We were in the middle of a long and wide valley, framed by mountains. July 25, 2019. Credit: NASA

We met up with the team in Stanley at the end of Highway 21 around dinner time. It’s a tiny town with a tiny population of 63 that is the launching point for seasonal visitors to the Sawtooth’s and surrounding national forests. After three hours of driving with no reception, it’s also a welcome oasis of internet and cell service within the wilderness – essential for meeting up with the Mobile Lab caravan.

In addition to Bruce, Jackson Kaspari from the University of New Hampshire and Jiajue Chai from Brown University were driving an RV to make the camping a little easier. In a separate car were Kathleen Brunke from Christopher Newport University and Carolyn Jordan from the National Institute of Aerospace with tents and camping gear. They were all looking forward to being in the field for FIREX-AQ.

“It’s a little like science camp,” said Carolyn. “You get to go out with all these people who study the same thing you do.” She raised her hands in an excited pantomime of sharing data. “What did you get? Here’s what I got!”

After dinner we headed out back the way we came a few miles down a long and wide valley with a stream running through it, and then off onto a lengthy gravel road to our campsite in the middle of the meadow.

We helped Carolyn set up tents for the night while the others got their instruments running. She joined them in the van right afterwards.July 24, 2019. Credit: NASA
We helped Carolyn set up tents for the night while the others got their instruments running. She joined them in the van right afterwards. July 24, 2019. Credit: NASA

Off in the distance a plume of smoke from the Shady Fire to the north drifted by the nearby hills. Before sunset and after testing the wind direction, the scientists got to work setting up their instruments in the van – running the power generator, opening intake valves and hatches to the outside air, attaching filters to catch particulate aerosols. It was a clear night, and in the end not much smoke made its way to the middle of the valley where we were.

“It’s a little like fishing,” Bruce said. You do your best to find a good spot based on the information and weather, but sometimes the smoke doesn’t bite.

Earlier in the week, Sunday night to Monday morning, however, the Mobile Lab at the same site caught a lot of smoke from a fire near the highway. The smoke plume sank to the valley around midnight, and the team measured the height of the smoke particles with an infrared laser looking upward and bouncing off the particles back to the laser.

Jackson climbs to the roof of the van to open and set up the inlet valve that will suck exterior air into the van. July 24, 2019. Credit: NASA
Jackson climbs to the roof of the van to open and set up the inlet valve that will suck exterior air into the van. July 24, 2019. Credit: NASA

In the van, each researcher had an instrument measuring different aspects of the smoke and addressing different science questions. Carolyn’s instrument measured the scattering or absorption of light by smoke particles. The scattering tells her about the size and shape of the particles, and the absorption something about their chemical composition. Kathleen was collecting particulates in the air that she will take back to the lab to measure for heavy metals – evidence that bits of soil got burned and swept up into the smoke plume – and PM 2.5, the particulate matter size that can cause respiratory problems for people who breathe it in.

Jackson’s instrument collected air into hand-blown glass chambers filled with mist that serves as seed points to collect nitrite (NO2), nitrate (NO3), and sulfate (SO4) that then run through chromatography to determine their concentrations. Jiajue’s instrument collected air samples to measure for nitrogen oxides and nitrous and nitric acid. Nitrogen compounds are essential for determining the role ozone plays in the atmosphere. Ozone reacts readily with other gases in chains of chemical reactions that can ultimately process harmful gases like greenhouse gases out of the atmosphere. Jiajue also uses nitrogen and oxygen isotope ratios to “fingerprint” the fuel source of the air – whether the smoke came from vehicles, soils or burned vegetation.

Jiajue prepares sample bottles for his instrument inside the Mobile Lab. July 24, 2019. Credit: NASA
Jiajue prepares sample bottles for his instrument inside the Mobile Lab. July 24, 2019. Credit: NASA
Bruce and Carolyn look at initial readings of gases inside the van. July 24, 2019. Credit: NASA
Bruce and Carolyn look at initial readings of gases inside the van. July 24, 2019. Credit: NASA

Bruce was a one-man show monitoring 14 instruments that doubled up some of the others’ measurements and also took measurements of major gases like carbon dioxide (CO2) and carbon monoxide (CO), whose ratio of one to the other can determine whether the smoke came from a hot intense fire (low CO) or smoldering fire (higher CO). Another instrument measures the mass of soot in the air, and others look at the optical properties of soot and various gases so that they can ultimately improve satellite interpretations of plume composition.

Together these individual measurements build a more complete understanding of how smoke particles and gases react and evolve in the atmosphere, what they say about their fuel sources, and ultimately how they affect the air quality people encounter downwind.

Kathleen sets up her instrument that will filter exterior air and capture airborne particles on filters. She'll take the filters, frozen to preserve them, back to her lab at the end of the campaign for analysis. July 24, 2019. Credit: NASA
Kathleen sets up her instrument that will filter exterior air and capture airborne particles on filters. She’ll take the filters, frozen to preserve them, back to her lab at the end of the campaign for analysis. July 24, 2019. Credit: NASA

On a smoky night, the researchers barely sleep. While some of the instruments are fully automated, they often monitor them until past midnight, and Kathleen and Jiajue have to swap out filters and sample bottles every few hours.

The night we were out they got a reprieve, but Bruce stayed up most of the night anyway to monitor the instruments and make sure everything was running smoothly. Also, the cold made it difficult to sleep. While it was 95 degrees F in sunlight, the dry, cloudless Idaho night doesn’t hold moisture, and so temperatures dropped to below freezing, making the noisy, generator-heated van the warmest spot in camp. Those of us without proper camping gear, ended up sleeping in the car.

Despite the cold, we woke to a beautiful sunrise and to smoke plumes from the Shady Fire edging the valley. The Mobile Lab team packed up and headed back to Stanley for breakfast and to call in to the morning briefing on fire activity to find out where they were going next.

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Fires and Smoke with FIREX-AQ: Live from Idaho

by Ellen Gray / BOISE, IDAHO/

NASA, NOAA and university researchers are on an Earth expedition this summer studying fires and their smoke in the U.S. West. On July 23 from Boise, Idaho, the Fire Influence on Regional to Global Environments and Air Quality or FIREX-AQ, kicked off its study of fire smoke, what gases and tiny particulates are in it, and how they evolve and travel over the course of the fire’s lifespan and beyond. By gaining a better understanding of fire behavior and smoke plumes from direct measurements, the research done here will benefit satellite measurements and air quality forecasting in the future, as well as improve our overall understanding of fire dynamics in the atmosphere and their effects on climate.

NASA's DC-8 flying laboratory (left) and one of NOAA's Twin Otters (right) overfly fires and smoke during the FIREX-AQ campaign. They are being hosted by the Idaho National Guard's 124th Fighter Wing in Boise, Idaho.
NASA’s DC-8 flying laboratory (left) and one of NOAA’s Twin Otters (right) overfly fires and smoke during the FIREX-AQ campaign. They are being hosted by the Idaho National Guard’s 124th Fighter Wing in Boise, Idaho.

I’m Ellen Gray, a NASA science writer, and myself along with two NASA video producers, Katy Mersmann and Lauren Ward, will be shadowing the science team in Boise over the next week, sharing what it’s like to do science in the field with NASA’s DC-8 flying laboratory, two NOAA Twin Otter aircraft, and NASA Langley’s Mobile Laboratory, among many other moving parts that are taking measurements of smoke from the source.

We’ll be posting our day-to-day updates on the @NASAExpeditions Twitter and NASA Expeditions Facebook account and our deeper dives here and on the @NASAEarth Twitter and NASA Earth Facebook accounts. So follow along and stay tuned!

Boise is home to the National Interagency Fire Center (NIFC), a multi agency coordination center for fighting fires across the United States. NIFC, the U.S. Forest Service, the Joint Science Fire Program, the Bureau of Land Management as well as the National Science Foundation, the U.S. Environmental Protection Agency, and the California Air Resources Board are all partners in the FIREX-AQ campaign.
Boise is home to the National Interagency Fire Center (NIFC), a multi-agency coordination center for fighting fires across the United States. NIFC, the U.S. Forest Service, the Joint Science Fire Program, the Bureau of Land Management as well as the National Science Foundation, the U.S. Environmental Protection Agency, and the California Air Resources Board are all partners in the FIREX-AQ campaign.

Land Ho! Visiting a Young Island

The three year-old volcanic island (black) as seen from the SEA drone. Credit: Woods Hole
The three-year-old volcanic island (center) as seen from the SEA drone. Credit: Sea Education Association / SEA Semester

by Ellen Gray

Excitement was in the air when research scientist Dan Slayback of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, approached a small trio of islands in the South Pacific island nation of Tonga. It was October 8th, and Dan had joined the scientists and students with the Sea Education Association’s SEA Semester South Pacific cruise to visit a three-year-old island he’d only seen from space.

“There’s no map of the new land,” Dan said. It erupted from the rim of an underwater caldera in early 2015, nestled between two older islands. The older islands were on some nautical charts at coarse resolution, and the satellite observations appeared to show shallow beaches on the south side of the new island that would allow them to land. However, while satellites are powerful tools for looking at land on Earth, they are not omniscient about all the details on the ground – these beaches turned out to be too steep and the waves too rough for an easy landing.

The SSV Robert C. Seamans of Woods Hole's SEA Semester program at Hunga Tonga-Hunga Ha'apai. Credit: Dan Slayback
The SSV Robert C. Seamans of SEA Semester program at Hunga Tonga-Hunga Ha’apai in October, 2018. Credit: Dan Slayback

When the volcanic island burst into being in January 2015 it immediately captured the attention of NASA scientists keen to understand how new islands form and evolve on Earth – which may also give them clues about how volcanic landscapes interacted with water on ancient Mars. The new Tongan island is one of only three that has erupted in the last 150 years that have survived the ocean’s eroding waves longer than a few months. Dan and his colleagues Jim Garvin at Goddard and Vicki Ferrini at Columbia University have been watching it from satellites since its birth, trying to make a 3D model of its shape and volume as it changes over time to understand how much material has been eroded and what it is made of that makes it partially resistant to erosion. But while high-resolution satellite observations are revolutionary for studying remote regions – such as tiny islands in the vast Pacific Ocean – they can only tell you so much without actually visiting the place on the ground.

Dan and the SEA scientists and students, as well as a Tongan observer, sailed around to the calmer northern coast of the island, which still has no official name and is referred to by the combined names of its neighbors, Hunga Tonga-Hunga Ha’apai (or HTHH for short). On October 9th, they spent the day taking GPS measurements of the location and elevation of boulders and other erosional features visible in the satellite image.

NASA researcher Dan Slayback standing on the beach of Hunga Tonga-Hunga Ha'apai. Credit: NASA
NASA researcher Dan Slayback standing on the beach of Hunga Tonga-Hunga Ha’apai.

“We were all like giddy school children,” said Dan of their visit. “Most of it is this black gravel, I won’t call it sand – pea sized gravel – and we’re mostly wearing sandals so it’s pretty painful because it gets under your foot. Immediately I kind of noticed it wasn’t quite as flat as it seems from satellite. It’s pretty flat, but there’s still some gradients and the gravels have formed some cool patterns from the wave action. And then there’s clay washing out of the cone. In the satellite images, you see this light-colored material. It’s mud, this light-colored clay mud. It’s very sticky. So even though we’d seen it we didn’t really know what it was, and I’m still a little baffled of where it’s coming from. Because it’s not ash.”

Editor’s  Note: Dan later learned that clayey materials washing out from the cone, even a cone from an ash-dominated eruption, is not unexpected. Similar mud deposits have been observed on other small oceanic island volcanoes, as a weathering product from tropical rains that wash fine particles down from the higher elevations and turn them into small mud-flows that are deposited in the low, flat areas around the base of the volcano.

Mud was only one of the surprises. Dan and the students were able to get up-close photos of the vegetation beginning to take root on the isthmus connecting the island to its neighbor, and patches likely seeded by bird droppings on the volcanic cone’s flank. A barn owl made a surprise appearance (they occur worldwide; the sighting was not, it turns out, particularly remarkable), likely living on the heavily vegetated older islands, as well as hundreds of nesting sooty terns that had taken shelter in the deep gullies etched into the cliffs surrounding the crater lake.

Vegetation taking root on the flat isthmus of Hunga Tonga-Hunga Ha'apai. The volcanic cone is in the background. Credit: Dan Slayback
Vegetation taking root on the flat isthmus of Hunga Tonga-Hunga Ha’apai. The volcanic cone is in the background. Credit: Dan Slayback
Sooty terns are nesting in the gullies around the crater lake. Can you spot the chicks? Credit: Dan Slayback
Sooty terns are nesting in the gullies around the crater lake. Can you spot the chicks? Credit: Dan Slayback

But Dan was there for the rocks. In addition to collecting small samples (with Tongan permission) for mineral analysis back at Goddard’s Non Destructive Evaluation Lab, the other main goal of his visit was to figure out what the actual elevation was of the island.

“The point is to try to take the satellite imagery and tie it to a known reference point, particularly the vertical elevation. The software that generates Digital Elevation Models (a 3D map) from stereo imagery is using a geoid model, and it’s not great in remote places like this. So if you were standing there with your GPS and you’re looking at the ocean at sea level and it’s telling you you’re at four meters elevation, you’re like, But I’m not! I’m at sea level,” he said. So he wanted to find a reasonable adjustment to the geoid model for local mean sea level.

The cliffs of the crater lake are etched with erosion gullies. Credit: Dan Slayback
The cliffs of the crater lake are etched with erosion gullies. Credit: Dan Slayback

Using a high-precision GPS unit with both a stable and mobile unit, Dan and the students helping him took about 150 measurements that narrow down each point’s location and elevation to better than 10 centimeters. In addition, they used SEA’s drone to do an aerial survey of the island for another layer of observations to use to make a higher-resolution 3D map of the island.

“It really surprised me how valuable it was to be there in person for some of this. It just really makes it obvious to you what is going on with the landscape,” Dan said. One feature that was eye-opening in person was the deep erosional gullies that run down the side of the volcanic cone. “The island is eroding by rainfall much more quickly than I’d imagined. We were focused on the erosion on the south coast where the waves are crashing down, which is going on. It’s just that the whole island is going down, too. It’s another aspect that’s made very clear when you’re standing in front of these huge erosion gullies. Okay, this wasn’t here three years ago, and now it’s two meters deep.”

A SEA student takes a GPS point in one of the gullies. Credit: Dan Slayback
A SEA student takes a GPS point in one of the gullies. Credit: Dan Slayback

Dan and the SEA Semester group only had one additional morning on the island before bad weather moved in and they had to retreat to the ship. Now back at Goddard, he’s processing the new data and developing a more realistic 3D model of the island, which he and his colleagues will use to figure out its volume and how much ash and volcanic material erupted from the vent on along the rim of the submarine caldera below. Big questions remain, such as what does the shallow sea floor around the island look like and are hydrothermal processes occurring that may solidify the material and allow it to resist erosion for decades to come. Dan hopes to return next year to find more answers.

 

Meet Corey Walker, NASA Earth Science Intern and Aspiring Educator

Corey Walker presents his research findings to the Student Airborne Research Program group. Credits: NASA / Megan Schill
Corey Walker presents his research findings to the Student Airborne Research Program group. Credits: NASA / Megan Schill

By Corey Walker / NASA ARMSTRONG FLIGHT RESEARCH CENTER, PALMDALE, CALIFORNIA /

My name is Corey Walker. One of the most incredible things I’ve done on paper is become a NASA intern through the agency’s Student Airborne Research Program, otherwise known as SARP. Why? I grew up in Etowah County, Alabama which has a poverty rate well above the national average. At the end of the year, I will be one of just 8 percent of people from my hometown who will have achieved a bachelor’s degree. I’ve come to recognize that the opportunity I’ve had is somewhat of an anomaly for many who have watched my success.

I wanted to participate in this Q&A blog to share my experience with the NASA SARP program and to express my gratitude towards those who have given someone like me a chance to succeed. I also want to encourage the next generation of student scientists to apply for opportunities like SARP to broaden their skill sets and to experience what field research and lab analysis is all about.

What do you think it takes to become a NASA intern

CW: The conditions that create a NASA intern are variable depending on who you ask. However, for me it begins with ordinary people who have extraordinarily impacted my life. Along the way family, friends, teachers, and mentors have taught me the value of perseverance,  working hard, and pushing yourself beyond known limits.

Corey interacts with fellow SARP interns on the flightline at NASA’s Armstrong Flight Researcher Center’s facility in Palmdale, California. Credits: NASA / Megan Schill
Corey interacts with fellow SARP interns on the flightline at NASA’s Armstrong Flight Researcher Center’s facility in Palmdale, California. Credits: NASA / Megan Schill

Why did you apply?

CW: The answer to this question lies in the evolution of my interests. For example, when I was a freshman, I was an English major. I applied the skills I learned with my time in the English department to the development of a YouTube channel, which I’ve since neglected. My sophomore year, I changed my major to nursing. While in this major, I applied myself to the rigorous study of science. Through this study, I produced a bit of character development and self-confidence. As science education molded me, I decided to study biology and education as a double major. I’m proud to report that I graduated this month. As a future science educator, I want to use my experience in the classroom to leverage curiosity and the understanding of complex systems. I also want to inspire the next generation to apply themselves towards their own challenging, individual goals like the one I achieved by working for NASA.

This isn’t the first time you’ve applied with the program. What inspired you to persevere and apply again?

CW: I have heard lots of teachers say something cliché like, “You can do anything you set your mind to.” I personally believe in this phrase, first because I am an optimist, and second because I think humans are powerful when they decide to act. However, I think that there is a responsibility that comes with believing this phrase. Personally, I think it would be unfair for me to tell my students to believe in themselves if I first did not believe in me. In a lot of ways, applying to SARP again is just myself modeling for students the act of taking responsibility for my beliefs. I also hope my second application to SARP teaches students an important lesson. Failure is feedback.

2018 Student Airborne Research Program Interns. Credits: NASA / Megan Schill
2018 Student Airborne Research Program Interns. Credits: NASA / Megan Schill

Why do you think internship opportunities like SARP are important for college students?

CW: I came to SARP from a small, liberal arts institution in East-Central Kentucky called Berea College. I am the first SARP alum from my school. The connections I made with this research experience will be extremely valuable to future generations. I intend to help someone else from Berea find the opportunity to work at NASA by connecting them to the network of scientists I have created. I also think opportunities like SARP are a great resume booster. This research experience under my belt will certainly prepare me better for graduate school.

What do you think undergraduate students can benefit from most by participating in opportunities like SARP?

CW: SARP is interesting because it puts you in an environment where you are forced to learn new things you’ve never thought about studying. As an educator, I am a big proponent of discovering new things. While at SARP, I was introduced to analytical tools and software like ENVI and MATLAB. I even had the opportunity to work with ArcGIS and ArcMap. This made me see a side of science that was utterly new and outside to anything I had ever contemplated.

Another thing that is beneficial about SARP is the way you get to be inspired by all kinds of interesting scientists and experiences. Some of my favorite moments were when I got to hold Sherwood Rowland’s Nobel Prize and see a real Mars lander being built at JPL for the 2020 mission.

Corey Walker sits in the cockpit jump seat aboard the NASA DC-8 during a science flight. Credits: NASA / Megan Schill
Corey Walker sits in the cockpit jump seat aboard the NASA DC-8 during a science flight. Credits: NASA / Megan Schill

Describe your research project and group.

CW: Something I noticed while flying in Southern California was all the tile or red-shingle roofs. This was certainly different from where I grew up and intrigued me. Because of my experiences being a volunteer firefighter with the city of Berea, I began to wonder how defensible red-shingle roofs were compared to wood shingle roofs if exposed to wildfire. This interest, along with help from mentors Alana Ayasse and Dr. Dar Roberts gave me the desire to develop a project where I mapped fire risk using remote sensing instruments. In my project, I successfully mapped materials like non-photosynthetic vegetation (NPV) or dead grass, green vegetation (GV) and soil and road in Goleta. I then compared maps I made to the location of the Holiday Fire, which started on July 11, 2018 and destroyed 28 structures.

How did you collect data for your research?

CW: I used data taken from NASA’s ER-2 16 days prior to the Holiday Fire. It was important for me to use data that was as close to the fire date as possible. I did this in order to accurately assess what kinds of materials were on the ground before the fire started.

The SARP Wildfires team collects field data in Central California. Credits: NASA / Megan Schill
The SARP Wildfires team collects field data in Central California. Credits: NASA / Megan Schill

What did you learn from the research?

CW: Not only did I show that the Holiday Fire occurred in a high fire risk area, but I also found interesting patterns. More specifically, my maps showed high fire risk in areas to the north and south of Goleta’s urban center where there is less road and more vegetation. My maps also show high fire risk in areas where property values are higher, which is a little alarming. For example, to the north, I found properties costing upwards of $700,000 surrounded with materials that could easily burn.

How do you plan to use this internship experience and your education going forward?

CW: Because of SARP, all the kids at the high school I teach at think I’m “cool.” This should be the objective right? It is interesting how working for a widely known name can inspire students and make them believe they could also do something “crazy” like working for NASA. Besides bringing my experiences into the classroom, I’ve decided I want to pursue a PhD in Earth Sciences and one day become a professor.

I’ve recently become interested in a hazards program at Oxford in the UK. I’ve certainly gained some self-confidence from getting to work for NASA, which has given me the desire to aim for a school like Oxford.

There is a professor named Dr. Tasmin Mather at Oxford who has used the European Space Agency’s Sentinel-1 to study volcanoes for the benefit of international communities. I find this work to be interesting as a scientist and volunteer firefighter. I like the way she uses science to inform the public of hazardous threats. I think it would be really cool to use my experience at SARP as a way to set me apart when I apply, so that I could one day work with someone like Dr. Mather.

Left to right: Chan Oh and Corey Walker. Chan was Corey’s roommate during college.
Left to right: Chan Oh and Corey Walker. Chan was Corey’s roommate during college.

Is there anyone else you’d like to recognize that has helped along your journey?

CW: I want to recognize and thank my family who have invested their time, resources and love into my success. I also had a number of teachers and mentors who went out of their way to push me out of my comfort zone. Lastly, I want to thank my wife Emily, who sacrificed time that could be spent together so that I could do science in California. Thank you all.

For more information on the Student Airborne Research Program and to apply visit: https://baeri.org/sarp-2019/

To read other blogs written by current and former SARP students visit: https://blogs.nasa.gov/earthexpeditions/?s=SARP

Chasing Clouds and Smoke Over the Southeast Atlantic

By Michael Diamond / SÃO TOMÉ AND PRÍNCIPE /

Michael is a PhD student at the University of Washington in Seattle.

Image 1: Michael Diamond in front of the P-3 at São Tomé International Airport before the October 10th, 2018, ORACLES flight. Photo credit: Rob Wood
Michael Diamond in front of the P-3 at São Tomé International Airport before the October 10th, 2018, ORACLES flight. Photo credit: Rob Wood

Our October 2018 deployment may be our last of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign, but it certainly won’t be our least. (We love each of our three deployments equally, of course.) During ORACLES, scientists from multiple NASA centers, universities, and other partners came together to study the complex interactions between smoke from fires on the African continent and low-lying clouds, called stratocumulus, over the Atlantic Ocean between September 2016 and October 2018.

Image 2: View of smoke produced by fires in southern Africa over low-lying clouds in the southeast Atlantic Ocean from onboard the P-3 during the October 10th, 2018, ORACLES flight. Photo credit: Michael Diamond
View of smoke produced by fires in southern Africa over low-lying clouds in the southeast Atlantic Ocean from onboard the P-3 during the October 10th, 2018, ORACLES flight. Photo credit: Michael Diamond

As my colleague Andrew wrote previously, climate models struggle to accurately capture the physical processes that occur when smoke particles, also known as aerosols, overlie and mix into clouds, in part because these processes occur at such small scales. The effects of aerosol-cloud interactions can include warming from sunlight being absorbed by the smoke and/or cooling from changes in the clouds’ brightness, coverage, and precipitation — it is still uncertain whether the heating or cooling effects cancel each other out or if one effect wins out in the end. We need the best observations we can get to better understand the fundamental physics and chemistry of this smoke-cloud system and use that knowledge to improve the models. Because the clouds and smoke we’re interested in are many miles away from land, the best way to study them is from the air.

Enter the NASA P-3 Orion: a four-engine turboprop plane that can directly sample the smoke plume and the clouds, from 20,000 feet in the air all the way down to just above the ocean surface.

Image 3: Michael Diamond (front) operating a Counterflow Virtual Impactor Inlet System (CVI), which lets instruments make aerosol measurements within the clouds, and Steve Broccardo (back) operating the 4STAR (Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, a sunphotometer that can measure smoke properties at multiple wavelengths of light, aboard the P-3 on the October 10th, 2018, ORACLES flight. Photo credit: Andrew Dzambo
Michael Diamond (front) operating a Counterflow Virtual Impactor Inlet System (CVI), which lets instruments make aerosol measurements within the clouds, and Steve Broccardo (back) operating the 4STAR (Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, a sunphotometer that can measure smoke properties at multiple wavelengths of light, aboard the P-3 on the October 10th, 2018, ORACLES flight. Photo credit: Andrew Dzambo

Initial results from our September 2016 deployment showed that, because it takes a fairly long time for the smoke from above to mix down into the cloudy layer, it may be best to study the smoke-cloud interactions by following individual cloud systems. This means we can account for how a cloud changes and evolves over time and how long the clouds and smoke have been in contact. For two of our ORACLES-2018 flights, we attempted to do just this, using a forecast model from the National Oceanographic and Atmospheric Administration (NOAA) to predict where clouds sampled on one flight would end up the next day, and then sampling the clouds there. For a fairly typical wind speed of around 10 knots, the clouds can travel approximately 300 miles in one day.

A great opportunity for this type of flight arose on October 2nd. The day before, a “pocket of open cells,” or POC, developed around the area we normally fly. In a POC, the stratocumulus clouds arrange themselves in a quasi-hexagonal pattern, with cloudy areas on the edges and clear skies in between. In “closed cell” clouds, which we sampled more regularly, the opposite pattern holds, with clear slots at the sides and overcast skies in between. During most ORACLES flights, we aimed to sample “polluted” clouds, with lots of aerosols in the air below the cloud. POCs are an interesting case because they tend to be very “clean,” removing aerosols from the air through drizzle. This precipitation is very likely the driving factor determining whether the clouds arrange themselves in open or closed cellular formations. We still have open questions remaining about whether aerosols can suppress precipitation and induce the open cells to transition into closed cells.

Image 4: True color image of the POC on October 1st from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The dotted black line shows the trajectory of a point (white circle) originally inside the POC for three days as it travels around the southeast Atlantic. The POC can be seen as the anvil-shaped collection of open cell hexagonal clouds between 8 and 12 degrees south and 0 and 8 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA Air Resources Laboratory (ARL)
True color satellite image of the POC on October 1st from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The dotted black line shows the trajectory of a point (white circle) originally inside the POC for three days as it travels around the southeast Atlantic. The POC can be seen as the anvil-shaped collection of open cell hexagonal clouds between 8 and 12 degrees south and 0 and 8 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA Air Resources Laboratory (ARL)

We first sampled the POC on October 2nd, flying above, below, and within the clouds. We were also able to sample another interesting feature: the white diagonal line of cloud that can be seen cutting through the POC near where we flew is called a ship track. Ship tracks are formed where the exhaust from ships emits particles and gases that form new aerosols, which can then interact with the clouds. (There are some other ship tracks visible in the satellite imagery from October 1st and October 2nd as well.) As expected, most clouds we sampled were drizzling and the below-cloud air was very clean. The more overcast linear feature in the ship track will help us better understand how clouds transition between open and closed cells.

Image 5: True color image of the POC on October 2nd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to one day later. The POC can be seen as the anvil-shaped collection of open hexagonal clouds between 6 and 10 degrees south and 2 and 10 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA ARL
True color satellite image of the POC on October 2nd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to one day later. The POC can be seen as the anvil-shaped collection of open hexagonal clouds between 6 and 10 degrees south and 2 and 10 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA ARL

On October 3rd, we set out on a mission to resample the POC and see how the clouds had changed and whether any smoke had been mixed into the below-cloud layer. We were heartened to see from our satellite imagery that the POC had traveled to roughly the same area we had forecasted. The POC by this time was dissipating: some well-developed open cells are still visible, but the POC boundaries had eroded and more “actinoform,” or lace-like, clouds had formed.

Image 6: True color image of the dissipating POC on October 3rd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to two days later. The POC can be seen as the collection of open cells and actinoform clouds between 6 and 9 degrees south and 3 and 9 degrees east.)
True color satellite image of the dissipating POC on October 3rd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to two days later. The POC can be seen as the collection of open cells and actinoform clouds between 6 and 9 degrees south and 3 and 9 degrees east.

More analysis will need to be done after we’ve had a chance to calibrate and quality control the data, but our initial readings suggested the below-cloud layer was still relatively clean, with some mixing of smoke from above evident.

At the end of this October 2018 deployment, data collection for the ORACLES campaign will be complete, but there will be plenty of science left to do. Not only do we have our own data to analyze, but there have been other American, British, French, German, and Namibian and South African teams studying similar questions in the same region that we will collaborate with. Together, the multiple field campaigns and model intercomparison projects just completed and currently in the works will greatly improve our understanding of smoke-cloud interactions over the southeast Atlantic and their implications for the regional and even global climate system.

Refining How We See Aerosols, Clouds, and Precipitation in Climate’s Big Picture

By Andrew Dzambo / SÃO TOMÉ AND PRÍNCIPE /

Andrew is a PhD student at the University of Wisconsin-Madison.

Crew and scientists preparing for the October 2, 2018 research flight aboard the NASA P-3 aircraft. Pictured: Amie Dobracki, University of Miami. Photo Credit: Andrew Dzambo
Crew and scientists preparing for the October 2, 2018 research flight aboard the NASA P-3 aircraft. Pictured: Amie Dobracki, University of Miami. Photo Credit: Andrew Dzambo

Climate models are essential tools to predict climate’s evolution in the next few decades and beyond. Given current computational capabilities, most global models cannot resolve every scale and process; therefore, we often parameterize (i.e. simplify) the mathematical representation of the processes to obtain results in a reasonable amount of time.

Cloud processes are among the most difficult to parameterize for a number of reasons: clouds form on many different spatial scales, have highly variable time scales, and require simultaneous knowledge of a large number of factors that affect their evolution. Precipitation processes are even harder to capture in climate models because they occur on more highly variable spatial and time scales.

Additionally, the presence of aerosols, such as smoke or dust, further complicates the problem because aerosols’ effects on cloud and precipitation processes often depends on the type and amount of aerosol present.  Overall, our knowledge of how aerosols interact with clouds and precipitation is highly uncertain, especially over remote areas like the ocean. In order to better understand these processes and their impacts on the global radiation and energy budgets – essentially, how heat moves around our planet – we require highly accurate measurements of these aerosol and cloud interactions.

Group picture of some of the science crew from the transit between Sal, Cabo Verde to Sao Tome: Andrew Dzambo (front), Amie Dobracki (middle-left), Art Sedlacek (middle-right), David Harper (back-top), Sam LeBlanc (back-middle), and Tony Cook (back-bottom). Photo Credit: Andrew Dzambo
Group picture of some of the science crew aboard NASA’s P-3 research aircraft from the transit between Sal, Cabo Verde to Sao Tome: Andrew Dzambo (front), Amie Dobracki (middle-left), Art Sedlacek (middle-right), David Harper (back-top), Sam LeBlanc (back-middle), and Tony Cook (back-bottom). Photo Credit: Andrew Dzambo

NASA’s Observations of Aerosols above Clouds and their Interactions, or ORACLES, field campaign has set out to do just that. We are collecting a highly thorough, robust dataset aimed at challenging our current theories about cloud/aerosol interactions and how aerosols affect cloud and precipitation processes in stratocumulus clouds. These clouds might not be as visually stunning as ones associated with severe weather, but to atmospheric scientists, they are very important because they cover a large fraction of Earth’s subtropical oceans and have a large impact on earth’s energy budget. The ORACLES campaign, taking place over the Southeast Atlantic Ocean, bridges an observational data gap where ground and airborne observations are presently limited.

On the October 3, 2018 research flight, the biomass-burning (aerosol) layer is seen just above the stratocumulus cloud deck. Photo Credit: Andrew Dzambo
On the October 3, 2018 research flight, the biomass-burning (aerosol) layer is seen just above the stratocumulus cloud deck. Photo Credit: Andrew Dzambo

Weather radars were first developed during World War II, and radar technology has since expanded considerably. In the United States, WSR-88D radars are capable of observing (nearly) the entire country and are capable of notifying meteorologists of impending rain, snow, or destructive storms. But these radars are designed primarily to detect rainfall or ice particles larger than a small drizzle droplet. However, stratocumulus clouds are made up of even tinier cloud droplets, so the weather radar is not the best observing tool for them. Instead we need a radar system specifically designed for cloud detection.

Enter the NASA Jet Propulsion Laboratory’s 3rd generation Airborne Precipitation Radar (APR-3). With development beginning back in 2002, this radar system operates at three frequency bands used to measure thin clouds and light precipitation (W-band), light to moderate precipitation (Ka-band) and moderate to heavy precipitation (Ku-band). This is the first airborne radar system capable of measuring the atmosphere at three frequencies for the same location, which means it can simultaneously detect clouds and precipitation.

During the ORACLES campaigns from 2016 through 2018, the stratocumulus cloud decks we see most often frequently go undetected by the lower frequency Ku and Ka channels. But by including the high frequency W-band radar we can now see the stratocumulus cloud and characterize its structure at a very high resolution.

Simone Tanelli (Jet Propulsion Laboratory) operating the APR-3 radar. Photo Credit: Andrew Dzambo
Simone Tanelli (Jet Propulsion Laboratory) operating the APR-3 radar. Photo Credit: Andrew Dzambo

Occasionally, the APR-3 system in ORACLES measures both the cloud and precipitation. Detecting precipitation in multiple radar frequencies is useful as the high frequency W-band measurements commonly attenuates when precipitation gets too heavy – meaning the signal is somewhat lost because precipitating raindrops are too large. On the other hand, the other radar bands (usually Ka-band for ORACLES) can see this precipitation with little to no fading of the signal. The end result is that the multiple channels gives us the ability to better characterize the precipitation that’s happening. In turn, that gives us an opportunity to possibly provide a more accurate estimate of precipitation magnitude in these stratocumulus regions.

This is an example of both precipitating and non-precipitating stratocumulus as seen by the APR-3 radar. The highly sensitive cloud radar (W band, bottom) sees both the clouds and precipitation, whereas the Ka (middle) sees only precipitation and the Ku band (top) sees only the heaviest precipitation. Yellows, oranges and reds indicate precipitation, and blues/greens indicate clouds. The white bar at 0 kilometer/kilofeet (1000 feet) altitude shows the surface. Image Credit: Andrew Dzambo
This is an example of both precipitating and non-precipitating stratocumulus as seen by the APR-3 radar. The highly sensitive cloud radar (W band, bottom) sees both the clouds and precipitation, whereas the Ka (middle) sees only precipitation and the Ku band (top) sees only the heaviest precipitation. Yellows, oranges and reds indicate precipitation, and blues/greens indicate clouds. The white bar at 0 kilometer/kilofeet (1000 feet) altitude shows the surface. Image Credit: Andrew Dzambo

The ORACLES APR-3 contributes one component of a highly robust dataset designed to study the effects of aerosols on cloud and precipitation processes. Other direct and remote sensing instruments from the ORACLES field campaign collect highly detailed information about aerosol type and amount in the atmosphere – both of which are needed to properly assess cloud/aerosol interactions and their net effect on precipitation. Ultimately, ORACLES will greatly improve how we describe aerosol/cloud/precipitation interactions in future climate models.