ORACLES in Namibia 2016: Studying African Fires from the Skies

September 6th, 2016 by Mike Tosca

As the soaking rains of the summer wet-season subside in early July, the vast savannas of the southern half of the African continent dry out and turn from green to brown to a crispy yellow. Local farmers take advantage of the dried-out vegetation and burn the aged remains of crops before plowing and harrowing in an effort to return vital nutrients to the soil. The result of all this dry-season burning is a large, thick, persistent plume of smoke that stretches from the eastern coasts of Mozambique out over the southern Atlantic Ocean, sometimes reaching past Ascension Island on its way to Brazil. In many years, this plume persists, almost unbroken, from August through October.

A team of 100 plus scientists from NASA and universities are here on the far west coast of Namibia in the small desert resort town of Swakopmund to study the impact that this expansive plume of smoke has on low cloud dynamics over the Atlantic Ocean. Our mission is called the Observations of Aerosols Above Clouds and their Interactions, or ORACLES.

A MODIS satellite image from 21-08-2013 showing abundant fire (red dots) and an expansive plume of smoke originating in Angola and stretching out over the open Atlantic where it interacts with low clouds. Credit: NASA

A MODIS satellite image from 21-08-2013 showing abundant fire (red dots) and an expansive plume of smoke originating in Angola and stretching out over the open Atlantic where it interacts with low clouds. Credit: NASA

We’re using two research aircraft – the P-3 and the ER-2 (shown below) – equipped with over a dozen instruments and team members from a more than a dozen countries, to study these interactions from above, below and even within the clouds and smoke. I personally work with an instrument that is on-board the ER-2, but, just last week (August 31), the P-3 aircraft had its first successful research flight over the open Atlantic and flew through some impressive regions of smoke.

Scientists and engineers working on the P-3 aircraft which is currently stationed at Walvis Bay International Airport. Photo by Mike Tosca.

Scientists and engineers working on the P-3 aircraft which is currently stationed at Walvis Bay International Airport, Namibia. Photo by Mike Tosca.

A spectacular image of the ER-2 aircraft doing a flyby at Walvis Bay International Airport on August 26, 2016. Photo by Brian Rheingans.

A spectacular image of the ER-2 aircraft landing at Walvis Bay International Airport on August 26, 2016. Photo by Brian Rheingans.

Before arriving in Swakopmund, I, personally, had the great privilege of seeing this impressive plume of smoke overland and in “the wild”. I spent three days touring the incredible Etosha National Park in far northern Namibia where I was able to see a menagerie of megafauna (elephants, lions, giraffes, oh my) juxtaposed against an almost surreal background of grey, smoky skies. It goes without saying that the thick smoke – which originated from biomass burning in many cases hundreds of miles away in Zambia and beyond – helped produce some of the most spectacular sunsets I’ve ever seen.

A family of elephants in Etosha National Park is an impressive foreground subject to a gray sky filled with biomass burning smoke originating in central Africa. Photo by Mike Tosca.

A family of elephants in Etosha National Park is an impressive foreground subject to a gray sky filled with biomass burning smoke originating in central Africa. Photo by Mike Tosca.

A brilliant sunset viewed through a layer of biomass burning smoke from Etosha National Park on August 18, 2016. Photo by Mike Tosca.

A brilliant sunset viewed through a layer of biomass burning smoke from Etosha National Park on August 18, 2016. Photo by Mike Tosca.

This research campaign is just ramping up, but the smoky skies and the cloudy Atlantic are already proving to be the perfect real-life research laboratory for questions about the complex and not-well-understood interactions between smoke particles and low clouds. I think I speak for the scientific community when I say that I’m looking forward to the incredible and first-of-their-kind data that are sure to come out of this campaign over the next month or so.

Mike Tosca is an research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Salinity Processes in the Upper Ocean Regional Study (SPURS): A Routine Dipped in a Secret Sauce

September 6th, 2016 by Maria-Jose Viñas

By Eric Lindstrom

Food service on the R/V Revelle.

Food service on the R/V Revelle.

Food aboard the R/V Revelle is a cornerstone of happiness and good morale. Jay Erickson and Richard Buck are the cooks during this voyage and have many years of experience working together on R/V Revelle. I followed their daily routine all day on Friday, September 2, so that I can give you some beyond-consumer incite about food on the R/V Revelle. I will stipulate that their work is very good indeed and that we have been getting well fed. Since scales don’t work at sea, no weight gain can be observed. So says the fat blogger.

Jay Erickson, Chief Cook on the R/V Revelle.

Jay Erickson, Chief Cook on the R/V Revelle.

Richard Buck, Cook, R/V Revelle.

Richard Buck, Cook, R/V Revelle.

I think it is best to describe this important aspect of life on R/V Revelle in two ways. First is the routine that makes food service run like clockwork every day. Second are the secrets or magic of shipboard food service that those on land might find curious or amazing. I can touch on only a few highlights.

I’ll start with the clockwork routine. Richard and Jay alternate work assignments. Each day one them does the hot food preparation and other has salad/cold food preparation, cleaning/dishwashing, and supply runs to the stores (three decks down). The next day they switch. The key menu options for hot food are generally decided on the prior evening. Only one day has a predictable menu – Sunday is steak day! Jay and Richard’s workdays are over 12 hours long with two short breaks. That is a heavy, relentless duty.

Breakfast preparation starts at 6:00 am. Breakfast food options are those of a typical American diner (e.g., eggs several ways, several meats, potato, pancakes, oatmeal, cereal, fresh fruit), without the short orders, and do not vary substantially from day to day. Most people do not vary in their breakfast food choices so I’d characterize it as the constant, dependable meal (least challenging for the cooks).

Salad bar at every meal.

Salad bar at every meal.

Hot meal of Balboa chicken and shrimp noodle soup.

Hot meal of Balboa chicken and shrimp noodle soup.

After a short break from about 8:30 to 9:00 am, lunch preparation begins with galley and dining room cleaning. Typical lunch and dinner menus include a featured main course, a couple of side dishes, a vegetarian option, and a soup. After lunch cleanup there is another break in the action from around 1:30 to 2:30 pm. Some preparation for dinner will have been started during the lunch service.

Birthday cake for Andrew and Peter.

Birthday cake for Andrew and Peter.

Dinner preparation includes renewal and refreshment of the salad bar, bread baking, and work on the main meal from soup to nuts, as they say. Every day there are some extras or special events as well. On my day in the kitchen there were two birthdays, so a decorated birthday cake was prepared over the course of the day. Likewise, fresh bread, cookies, or a special dessert might be created for the dinner service.

As I learned over the course of the day, the vast share of labor goes into food preparation and cleanliness. The R/V Revelle professional facilities allow for the rapid and efficient cooking of food for 50-60 people. However, the washing and chopping of large quantities of fruit and vegetables, and meat handling are labor intensive. So too are the good habits of kitchen hygiene that assure that everything is done right and sparkling clean at all times. As you might expect, the work is hard enough without everything being shipshape and well organized. Fastidiousness was a hallmark of Jay and Richard’s work.

There are many challenges to creation of good meals at sea. Obviously motion of the ship can be a big issue. A ship’s cook is a cook who has mastered the art of corralling sloshing food! Richard told me of attempts to bake a level cake in the seas of the Southern Ocean. Rather than having it baked into the leaning cake of Pisa, he tried to balance the sea motion by turning the cake in the oven every few minutes to counter the sloshing of the batter. In that case, the ocean won…but I think the birthday recipient appreciated the effort nonetheless.

Fresh bread just out of the oven.

Fresh bread just out of the oven.

Jay shared an interesting secret of leftovers. Oatmeal is available for breakfast every day. Leftover oatmeal is mixed with water and yeast after breakfast and the slurry left to ferment. It is transformed by this effort of the microbes and a resourceful cook into the delicious bread at dinner!

Let us admire a three-week-old lettuce, looking like it was fresh.

Let us admire a three-week-old lettuce, looking like it was fresh.

A great deal of science and experience goes into the food storage on a ship. Three weeks at sea and we still have lettuce and perfect avocados. That never happens for me at home! While each fruit and vegetable seems to have its own story with regard to ripeness at purchase, storage, and revitalization, the keys to longevity seem to be in the cold room temperature and humidity plus the skills of Jay and Richard to give foods a second chance. Lettuce, for example, might look finished due to a dehydrating stay in the cold storage, but skilled knife work, a cold bath, and a little secret chemistry can return lettuce to salad fitness!

We are all in debt to the skill and labor of Richard and Jay. We will feel the full extent of the deliciousness they loaned to us when we climb on the scale back home!

Salinity Processes in the Upper Ocean Regional Study (SPURS): Chasing the Elusive Surface Salinity Profile

September 2nd, 2016 by Maria-Jose Viñas

By Eric Lindstrom

The R/V Revelle and the Lighter-Than-Air InfraRed System, as seen from the Surface Salinity Profiler.

The R/V Revelle and the Lighter-Than-Air InfraRed System (on the left corner), as seen from the Surface Salinity Profiler. Credit: Dan Clark.

Kyla Drushka from University of Washington Applied Physics Laboratory (APL) received a National Science Foundation grant to participate in SPURS-2. It is one cornerstone of our work and is entitled “Rain-Formed Fresh Lenses in SPURS-2.” The idea of rainfall resulting in freshwater puddles or lenses at the sea surface is (perhaps) easy to imagine but is very tricky to observe and study in the real world. SPURS-2 will provide a wealth of new data on this subject with which to test the fidelity of our scientific imagination.

A beauty shot of the Surface Salinity Profiler.

A beauty shot of the Surface Salinity Profiler.

Kyla and the APL crew have a variety of instruments aboard R/V Revelle but the Surface Salinity Profiler (SSP) is central to SPURS-2 science objectives. When you want to know the fate of rainwater after it hits the sea surface, measuring salinity (or equivalently the amount of freshwater) in the upper meter of the ocean is crucial. The profile of salinity in that top meter of the ocean is elusive for a number of reasons – technical and logistical. Technically, salinity sensors require some time and bubble-free water flow to make the measurement. However, normally the sea surface is rapidly moving up and down (because of waves!) so a sensor is not always in the water and away from bubbles until it is several meters below the surface. Finding a way to tow salinity (and other) sensors at fixed, shallow depths following the motions of the sea is another approach. APL scientists and engineers including Andy Jessup, Bill Asher, and Dan Clark designed the SSP to apply this approach.

How the Surface Salinity Profiler runs outboard the ship -- photo taken from the Lighter-Than-Air InfraRed System balloon camera.

How the Surface Salinity Profiler runs outboard the ship — photo taken from the Lighter-Than-Air InfraRed System balloon camera.

Dan Clark, APL engineer extraordinaire.

Dan Clark, APL engineer extraordinaire.

The SSP platform is a converted paddleboard with a keel and surfboard outrigger. It is tethered to the ship so it skims the sea surface outside the wake or influence of the ship. Below the paddleboard, on the leading edge of the keel, are salinity (and temperature) sensors at depths of 10 centimeters (4 inches), 30 centimeters (1 foot), 50 centimeters (1.64 feet), and 100 centimeters (3.28 feet), microstructure sensors (to estimate turbulence), and cameras. The Salinity Snake (see my last blog entry) supplements the SSP by providing temperature and salinity in the upper few centimeters of the ocean. The SSP can be towed for many hours before the instrument batteries need refreshing.

Deployment of SSP is most informative when there is a rain event, leading to stratification of the near-surface ocean with less dense fresher water on top of denser saltier water. If there is a rain event ahead of the ship, the SSP goes in the water. Then it can measure how the ocean changes over the periods from before rain, during rain, and recovering from rain. Salinity from several depths and simultaneous turbulence estimates are then used to determine how rainwater mixes into the ocean.

Suneil Iyer with Surface Slainity Profiler on deck (sensor to bottom left on keel)

Suneil Iyer with Surface Salinity Profiler on deck (sensor to bottom left on keel)

Suneil Iyer is a new graduate student at University of Washington who will work with Kyla on interpretation of the microstructure measurements from the SSP data. He just arrived in Seattle from his hometown of Kansas City, Kansas, one week before the R/V Revelle departure from Honolulu. He just had time to find an apartment before jumping on a plane for SPURS-2. Graduate school in oceanography can be a blast of new experiences! This is not his first exposure to physical oceanography: Suneil worked on tides in estuaries during his undergraduate work at University of South Carolina.

-Kyla Drushka working on the Surface Salinity Profiler.

Kyla Drushka working on the Surface Salinity Profiler.

Kyla Drushka joined UW in 2014 after PhD work at Scripps Institution of Oceanography. She is now an active member of NASA’s Ocean Salinity Science Team and the mission science team for the Surface Water Ocean Topography satellite that is planned for launch in April 2021.

This blog entry goes to press near an auspicious moment on R/V Revelle SPURS-2 voyage. Saturday at 2 am (local time) is the halfway point of our expedition! In our oceanography lexicon we would call this the “hump day” for our voyage. For all you land-loving 5-day-a-weekers hump day might mean Wednesday. For the 24/7 work at sea, we really have only a “hump moment” to mark the halfway point of a continuous work schedule. Like any good NASA activity, people aboard have countdowns running to both our hump moment and our arrival back in Honolulu (8 am on Sept. 23). Amusement is in short supply!

Salinity Processes in the Upper Ocean Regional Study (SPURS): Snakes on a Ship!

August 31st, 2016 by Eric Lindstrom

By Eric Lindstrom

Salinity snake

A longstanding technical challenge for oceanography has been how to measure the sea surface – temperature, salinity, gas exchange, or surfactants – to name a few examples. Obviously enough, the surface is where the ocean and atmosphere interact and exchange heat, freshwater, gases, momentum, and particles of all kinds. So, how do we measure the properties and exchanges right at the surface? If we are on a ship or any floating platform, the platform disturbs the surface. From satellites we can measure many properties of the surface but only on very broad scales. The R/V Revelle, right now, is the ship showing how modern science is meeting the challenge. Let me tell you about some key elements.

Julian Schanze from Earth and Space Research in Seattle and Jim Edson from University of Connecticut have brought two instruments aboard with innovative ways to measure the temperature and salinity at the surface – the Sea Snake for temperature (Edson) and the Surface Salinity Snake (Shanze) for, obviously, surface salinity. The former places a temperature sensor at the end of flexible hose that is hung outboard from the bow of the ship (near the wake), to continuously measure temperature. The Salinity Snake, outboard of the wake passes water through a vortex de-bubbler and thermosalinograph to obtain an estimate of salinity within inches of the ocean surface. It is an awesome “contraption” (with no offense to Julian).

The Salinity Snake being deployed over the starboard side.

The Salinity Snake being deployed over the starboard side.

Julian Schanze's birthday balloon.

Julian Schanze’s birthday balloon.

Today is Julian’s birthday so all the Salinity Snake gear has been draped with colorful paper snakes carrying birthday greetings. Julian participated in SPURS-1 in 2012 and has since received his PhD and is making a name for himself by tackling surface salinity science from gadget to satellite and from seawater intake to space. It is wonderful to have someone so capable on the NASA Ocean Salinity Science Team!

Andy Jessup, our chief scientist from University of Washington Applied Physics Laboratory and Michael Reynolds from Remote Measurements and Research Co. in Seattle have brought a dazzling array of instruments for measuring and probing the skin temperature of the ocean. The surface of the ocean is known to have a cool skin at the molecular level. Photos of the sea surface with infrared cameras reveal complex and interesting patterns as a result of mixing, wave breaking, surfactant conditions, and wind. NASA has always had a deep interest in skin temperature because satellites do measure this skin temperature while every probe you stick in the ocean measures something deeper and different than skin temperature. From the Revelle, Andy and Michael are using several infrared radiometers and cameras to measure and depict the sea surface skin temperature. There is one on a boom to measure outboard of the ship wake, one mounted on the rail to look outward from the ship and another on a balloon to take infrared photos of the skin from 300 feet above the ship (the Lighter-Than-Air InfraRed System – LTAIRS.)

The laboratory end of the Salinity Snake and Carbon Dioxide analysis.

The laboratory end of the Salinity Snake and Carbon Dioxide analysis.

LTAIRS ascends toward 300 feet.

LTAIRS ascends toward 300 feet.

Eric Chan, from University of Hawaii, is aboard measuring making a suite of carbon dioxide, pH, and Dissolved Inorganic Carbon measurements for principal investigator David Ho. They study the exchange of carbon dioxide across the air-sea interface and they’re particularly interested in how rainwater on the surface of the ocean impacts the gas exchanges.

The array of instrumentation aboard Revelle is quite astonishing and the technical innovations displayed in measuring the sea surface are truly remarkable. And I haven’t even mentioned the Surface Salinity Profiler yet in this blog post. I have been teasing you with that since the start of the voyage and I PROMISE to give it a blog entry all to itself!

Today is also the birthday of the R/V Revelle Captain, Christopher Curl. I am sure I speak on behalf of the entire SPURS-2 science party when I offer him a hearty “HAPPY BIRTHDAY!” and say how pleased we are with the entire ship and crew of R/V Revelle. I guess that sharing the ship with a group of rare ocean-skin specialists with sea snakes is not how he imagined this birthday, but he is quick with a smile and will roll with our skinny offerings!

ATom 2016: World Survey of the Atmosphere: Traveling the Length of the Atlantic Ocean, Part 2: Greenland!

August 31st, 2016 by Steve Wofsy

I have always wanted to visit Greenland, the “ground zero” for climate change. Its ice cap rises more than 3,200 meters (2 miles!) above sea level and it holds so much ice that if it all melted, the height of sea level would rise by 7 meters (23 feet). The landscape is stark and inhospitable for most plants and animals. Greenland’s location makes it very sensitive to climate change, and it has a dynamic geological history as a result. It is undergoing rapid change now, as shown in the chart below. Greenland is “ground zero” for climate change.

The loss of ice mass by the Greenland Ice Sheet from 2002 to 2015, measured by NASA's Gravity Recovery and Climate Experiment (GRACE) and by the DC8 in NASA's Operation IceBridge. Each gigaton of ice lost adds about 1 cubic kilometer of water to the oceans. The ice sheet has lost significant mass every year since measurements began in 2002.

The loss of ice mass by the Greenland Ice Sheet from 2002 to 2015, measured by NASA’s Gravity Recovery and Climate Experiment (GRACE) and by the DC8 in NASA’s Operation IceBridge. Each gigaton of ice lost adds about 1 cubic kilometer of water to the oceans. The ice sheet has lost significant mass every year since measurements began in 2002.

For our flight to Greenland, the DC8 took off from Lajes air base in the Açores and headed directly to the ice sheet, traversing its length along the western edge. Our destination was the Canadian scientific base at Eureka (80o N), off the northern coast on Ellesmere Island’s Fosheim Peninsula. Instruments at this station record the total amount of greenhouse gases and pollutants between the Earth’s surface and the Sun. Our goal was to measure these gases at each altitude in the atmosphere, in order to check the accuracy of these data. We would then head south and land at Kangerlussuaq, on Greenland’s west coast.

The ice cap was mostly covered in clouds until we reached the northern part of Greenland. When we saw the ice surface, it showed many dark features, including melt ponds and dark hills, especially at the edge of the ice sheet.

Lonely iceberg floating at off the eastern coast of Ellesmere Island, Canada. Satellite data show that areas around Ellesmere Island, that formerly retained floating ice all year round, are now ice free like the waters in this image.

A lonely iceberg floats off the eastern coast of Ellesmere Island, Canada. Satellite data show that areas around Ellesmere Island that formerly retained floating ice all year round are now ice free, like the waters in this image.

While flying over Ellesmere Island, I snapped a photo that dramatically illustrates how dark surfaces put heat into the atmosphere. The picture shows currents of air being warmed by dark, ice-free rock, rising up along the slopes of small hills and producing the little cloud right at the top of each one. This is the way that heat absorbed by the rocky surface is distributed throughout the lowest layer of the atmosphere.

The rocky hills of Ellesmere Island absorb energy from sunlight and from heat radiated by the atmosphere ("longwave radiation"). This unusual photo shows the warm, dark rocky surface heating the air, causing warm plumes to rise and forming small cloud caps over each hill. The process efficiently transfers heat from the surface to the atmosphere (Photo: Steve Wofsy).

The rocky hills of Ellesmere Island absorb energy from sunlight and from heat radiated by the atmosphere (“longwave radiation”). This unusual photo shows the warm, dark rocky surface heating the air, causing warm plumes to rise and forming small cloud caps over each hill. The process efficiently transfers heat from the surface to the atmosphere (Photo: Steve Wofsy).

When we flew out over the sea, we could see that the waters off shore were almost completely free of ice. Occasionally we saw a few icebergs, or small amounts of ice near shore, but otherwise we saw very little floating ice.

The floating ice in the Arctic does not store a great mass of water like the Greenland’s land-based ice sheet, but it does have a very strong influence on regional climate. When the ATom mission started in early August, we flew over the Beaufort Sea north of Alaska, up to 80oN, and saw ice floes covered with dark melt ponds and interspersed with dark areas of open water. Ice started to break up in this area especially early this year, and with all that dark water absorbing heat from the sun and from the atmosphere, I wondered if most of the Beaufort Sea might become ice free by summer’s end. Now we were back!

Satellite data show that the Arctic Ocean did not lose all of its ice. But the Beaufort Sea did lose its floating ice, as far north as 75o N, and 30 to 70% was lost at 80oN. Water temperatures became quite warm off the Arctic coast of Alaska, maybe just about swimmable for a New Englander like me (5 – 10 C, 40 – 50 F). This large expanse of warm water will tend to make the fall season warmer and provide more snowfall in the Arctic than in former times, when the ice persisted more extensively on the ocean surface. The loss of floating ice amplifies itself, a process called “positive feedback.” As open water and melt ponds cover more area, the ice and surrounding water absorb more energy, leading to more ice loss, more energy absorbed, etc.

This year the overall loss of floating ice was among the greatest ever observed, although it did not quite match the record set in 2012. Indeed, as we were flying over Ellesmere, the large luxury cruise ship Crystal Serenity was reportedly starting the first crossing of the fabled Northwest Passage by a ship of its type, with 1000 paying passengers.

I also photographed the calving edge of a huge tidewater glacier, where huge pieces of ice (bigger than a football field, weighing 1 million tons or more) break off the glacier and drop into the sea. In this picture, you can see how dark the surface of the glacier has become as it travels to the sea, in contrast to the clean blue ice below. The darkening accelerates the melting of the glacier; it is due to deposition of some of the pollutants (soot) that we measure, and also to algae that grow on the ice. Scientists don’t yet know how much of this dark material is “natural” versus human-caused, and they are studying the ice to understand how much darkening is caused by deposition in the form of soot from fires or by pollution-related nutrients that stimulate the growth of algae.

he end of the line: calving front of a tidewater glacier in western Greenland. As ice flows down from the Greenland ice cap to the sea, the surface darkens due to deposition of atmospheric pollutants and growth of algae. The picture shows the boundary where the moving glacier enters the ocean. Huge pieces of ice break off ("calving") the leading edge and drop into the water—the origin of icebergs. (Photo: Steve Wofsy)

The end of the line: calving front of a tidewater glacier in western Greenland. As ice flows down from the Greenland ice cap to the sea, the surface darkens due to deposition of atmospheric pollutants and growth of algae. The picture shows the boundary where the moving glacier enters the ocean. Huge pieces of ice break off (“calving”) the leading edge and drop into the water—the origin of icebergs. (Photo: Steve Wofsy)

After flying over Eureka and the west coast of Greenland, we landed in Kangerlussuaq, just a short distance south of the Arctic Circle.  The area around Kangerlussuaq is stark and beautiful. The town is very reminiscent of many communities across the Arctic. It lies in the midst of a deglaciated area of bare rock mountains and a thin layer of tundra, in a lovely fjord. The river roars like a freight train as it goes under the bridge, carrying meltwater from the ice cap to the sea. The weather was very warm and dry. My afternoon run was interrupted by an encounter with a musk ox. The Sunday dinner at the Boat Club may have been the best of my month long trip around the world, featuring at least eight types of smoked or cured fish. This country is really breathtaking. But it was also a rather sad place, very, very quiet, with dozens of buildings left empty after the closing of the extensive military facilities when the Cold War ended, and the summer had been much warmer than average, drying up soils and plants.

After two days in Kangerlussuaq, we set out for home across Arctic Canada, arriving for a brief overnight in Minneapolis. We stayed at a hotel just across the road from the Mall of America, a vast place with reportedly 30-40 million visitors per year. The contrast with Kangerlussuaq was very dramatic—scenery, culture, sounds, smells, climate, air quality.

This transition was in many ways so typical of the ATom experience, and ATom science. We went from the high desert, with its fires and searing heat, directly to the floating ice near the North Pole, then Hawaii and American Samoa in the subtropics, then suddenly to winter in New Zealand and Chile, back to the subtropics on Ascension Island and the Açores (Portugal), and then again to a land of ice caps and glaciers in Greenland – all in the space of three weeks.

We measured the chemicals in the atmosphere, from bottom to top and along the whole route, and all in the space of just over three weeks. We saw some stunningly dirty air even in the middle of the ocean, in the subtropics and in the Arctic, with a lot of pollution coming from biomass fires, and also some very clean air. Our instruments are extremely sensitive, though, and in even the remote region of the Antarctic polar vortex, we appear to have detected traces of pollution.

After traveling on the DC8 across both the Atlantic and the Pacific, the world seemed smaller than ever before, and the atmosphere, not at all infinite or inexhaustible.

The goal of ATom is to learn about how the most remote parts of the atmosphere are affected by pollutants emitted on land. We have a lot to work with! It will take months to analyze our data and really understand what we have measured, and to assess what we have learned about humanity’s impact on air quality and climate. We also have a lot of memories and impressions (and some sleep to catch up on). I know it will take me months, or years, to fully process what I have experienced and, along with the wonderful ATom team, to extract the quantitative scientific information we need to understand the environment.

 

This image shows a deglaciated region in western Greenland, with the ice cap in the background. (Inset: Map of Greenland, showing location of our landing site at Kangerlussuaq at 67o N, 50.7 W). According to Richard Alley of Penn State University, this area around Kangerlussuaq was deglaciated at the end of the last ice age, 8-10,000 years ago, but ice returned and scraped the ridges bare during the Little Ice Age, a period between about 1300 and 1870 AD during which Europe and North America had colder winters than in the 20th century.

This image shows a deglaciated region in western Greenland, with the ice cap in the background. (Inset: Map of Greenland, showing location of our landing site at Kangerlussuaq at 67o N, 50.7 W). According to Richard Alley of Penn State University, this area around Kangerlussuaq was deglaciated at the end of the last ice age, 8-10,000 years ago, but ice returned and scraped the ridges bare during the Little Ice Age, a period between about 1300 and 1870 AD during which Europe and North America had colder winters than in the 20th century.

 

The NASA DC8 Flying Laboratory in Kangerlussuaq, Greenland. Inset: Our flight paths during ATom-1. We overnighted in 11 different time zones at 10 sites (one clock shift) in 23 days, covering 65,000 km (40,500 mi, equal to 1.6 times around the earth). We made 160 vertical soundings, and measured more than 300 chemical and aerosol parameters.

The NASA DC8 Flying Laboratory in Kangerlussuaq, Greenland. Inset: Our flight paths during ATom-1. We overnighted in 11 different time zones at 10 sites (one clock shift) in 23 days, covering 65,000 km (40,500 mi, equal to 1.6 times around the earth). We made 160 vertical soundings, and measured more than 300 chemical and aerosol parameters.

Notes from the Field