A Satellite Scientist Visits the Ice, Alaska 2016: Challenge Completed

June 3rd, 2016 by Maria-Jose Viñas

By Walt Meier

A site at the the Inupiat Heritage Center in Barrow, AK.

A sign at the the Inupiat Heritage Center in Barrow, AK.

Jun. 1, 2016 — We started our last day of the camp with a morning visit to the Inupiat Heritage Center to learn more about the indigenous local culture. Many of the Inupiat in Barrow still live their traditional subsistence lifestyle – hunting, trapping, and fishing for food. They do however take advantage of modern technology to make their way of life a bit easier and safer. For example, now machines have replaced dogsleds and rifles have replaced harpoons. But for some things, the old ways did not need to be modernized: the sealskin umiaq kayaks are lighter (easier to carry across the ice) and more navigable in the narrow leads of open water common to the area than anything manufactured today. And the fur-lined coats, pants, and boots are lighter, warmer, and repel moisture better than any modern outdoor gear.

A painting of whale hunting at the Inupiat Heritage Center.

A painting of whale hunting at the Inupiat Heritage Center.

The Inupiat way of life is governed by the seasons. There is a season for whale hunting, for seal hunting, for polar bear hunting. The dark, cold winter season is a time to stay indoors and sew new clothes or repair old clothes. Festivals mark the seasons where the community comes together to celebrate and reinforce the bonds between families.

After visiting the heritage center, we headed back to our base for a final meal. Several times during the week, our field leader, Don Perovich, said that the key for a successful field expedition is “to eat as much as you can as often as you can.” And we were certainly well fed throughout, with plentiful sandwiches, instant soups, chips and crackers, and all-important chocolate for our typical mid-day meals. But our final meal in Barrow was a step above, thanks to Elizabeth Hunke at Los Alamos National Laboratory. She proved herself not only a top-notch sea ice modeler but also a great chef, putting together a delicious meal of spaghetti, garlic bread, and salad.

Last meal in Barrow.

Last meal in Barrow.

Then it was time for our final sessions, presenting the data we collected and discussing our Grand Challenge efforts. Unfortunately, the data collection the previous day did not go as smoothly as we had hoped. We couldn’t collect albedo measurements because the instrument didn’t work yesterday. But this type of things is not at all unusual in field work. As Don said: “In Arctic field research, it’s important to make a plan; it’s also important to not become too enamored of that plan” because something inevitably will go awry and you have be prepared to adapt.

So we couldn’t directly compare one of the key surface features between the two sites. However, we had other data we could look at. The new site to the north was 10-20 centimeters (4-8 inches) thicker than the original southern site. So there was less melt there and the ice was likely to last longer there. And while we lacked some data, we had models we could use. Many people think of modeling simply as predicting the future – and indeed models are used for that purpose (e.g., weather forecasts), but models, particularly climate ones, are also used to investigate processes and learn how climate responds to different parameters. Though we didn’t have albedo data, we could adjust albedo in the model and see how that affected how the modeled sea ice evolves in the future.

Grand Challenge results.

Grand Challenge results.

Several folks worked late into the previous night to process data and run the sea ice model. We obtained climatological weather data, input the data into the model and run it for the first two weeks in June. The results showed that the melt was strongly affected by the albedo of the surface and the amount of incoming sunlight, and that there will likely be substantial differences between the two sites. In a sense this isn’t terribly surprising, but to see such variation over such a small distance (the two sites were separated by only a couple miles) and within such short time periods (two weeks) is sobering. Large-scale complex models and satellite data cannot (yet) resolve such variability. There is still much research to do, and those of us at the camp have come away a greater appreciation for the challenge.

We finished up by discussing future plans. The goal of this camp wasn’t simply to get everyone together for one week, but to start new collaborations between modelers, satellite folks, and field researchers. We discussed several ideas to build upon the start we’ve made, keep momentum going, and convey what we learned to the broader sea ice research community. With that, it was time to head to the airport and begin our long journeys home.

Another tradition Don has is to bring a lollipop to each field expedition. When the expedition is done, he pulls it out as a reward for a job well done. At the beginning of our camp, he gave each of us a lollipop. It was up to us to decide when we were done. Some pulled theirs out after we wrapped up the meeting; some enjoyed theirs at the airport. I waited until the plane left the ground.

And so my adventure on the ice has come to an end. I can’t say I’m an expert in the field or ever will be. But it has been a rewarding week for me. I’ve gained a lot of knowledge about what it takes to do field work. I’ve gained an even greater appreciation of the value of field observations, as well as modeling studies. Hopefully I was able to give participants a greater understanding of satellite data. And finally, now when someone asks me if I’ve been on the sea ice, I can say “Indeed I have!” I still have the taste of the lollipop in my mouth to prove it.

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Until the next time, Walt.

NAAMES (North Atlantic Aerosols and Marine Ecosystems Study): NAAMES-II Expedition: June 1, 2016

June 1st, 2016 by Kristina Mojica

After escaping from heavy seas, we are heading back to port. This will be not a short travel, it will take about 5 days to arrive at Woods Hole. But all the time and effort of science team and crew members are worthy in order to explore one of the most amazing ecosystems: oceans.

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One drop of seawater is a whole microbial universe. I like to imagine this micro universe as a jungle, full of organisms of different kinds and sizes, predators eating others for meals, bunches of little organisms working together to produce food or defeat a stronger one which eventually will be a meal, or even some guys eating the leftovers of a big feast. In these descriptions you can imagine jaguars, ants, piranhas, or vultures, but no, I am talking of tiny living beings such as bacteria, copepods and protists.

There are many ways to classify these microbes: by size, shape, or which functions they carry out in the community, just as we do with animals and plants. Sounds easy, but is not; these features are difficult to describe in microorganisms simply because, well, they are micro. Even with the best microscopes available, microbial characterization is not an easy task, and that is where our job starts. As all living beings, microbes contain a genome made of DNA inside their cells. The genome is a whole set of instructions which allow the correct development and functionality of the cells. We take advantage of a set of genes (pieces of the genome which codify for individual instructions) that are common for all organisms and can be considered a fingerprint. The more similar this print (sequences of DNA components) is, the more probable we are talking about the same kind of organisms. So, we use this genome segments to classify the community of the samples collected at different stations and depths across the North Atlantic Ocean.

The CTD rosette where sample water is collected from different depths within the ocean. Photo: Luis Avellaneda

The CTD rosette where sample water is collected from different depths within the ocean. Photo: Luis Avellaneda

Doing this classification we can calculate at each sampling point the relative abundances of the different species that comprise the community, our microbial jungle. Why is this important? Well, imagine some part of this magnificent micro-jungle where we cannot see any bananas left in the banana trees; that would be a very strange situation, but if we know that in that jungle area the abundance of monkeys is very high, we can figure it out what is happening there. The same thing occurs in the microbial universe, certain organisms prefer to consume or produce specific compounds.

Having a high-resolution characterization of microbial species composition and how this composition changes at different sites or times, help us to correlate them to the different data that my ship fellows are generating. In that way we can describe this invisible jungle, their dynamics, and the collective consequences that these lively drops of water are producing in our planet.

North Atlantic common dolphin. Photo: Luis Avellaneda

North Atlantic common dolphin. Photo: Luis Avellaneda

Written by Luis Avellaneda

NAAMES (North Atlantic Aerosols and Marine Ecosystems Study): NAAMES-II Expedition: May 31, 2016

June 1st, 2016 by Kristina Mojica

PMEL Aerosol Group

Aerosols are another name for particulate matter in the atmosphere. Aerosols are important because in clear skies they can scatter sunlight back to space can act to help cool the planet. Aerosols are also important because they can act as a site for water to condense on and form cloud particles. Particles that water can condense on are called Cloud Condensation Nuclei, CCN. In fact the concentration of CCN can greatly affect the optical properties of the cloud that is formed when air is lifted and cooled. If there are a small number of CCN the resulting cloud will have a small number of large droplets. If there are a much larger number of CCN the resulting cloud will have a large number of small droplets. Even though the liquid water concentration in both clouds is the same, the cloud with the large number of small droplets will be much whiter, and reflect more sunlight then the cloud with the small number of large droplets.

It is believed that Aerosols can thus counteract some of the present and future greenhouse warming, and it is vital to understand the processes that create and modify aerosols in the marine atmosphere.

Our group from NOAA-PMEL and the University of Washington JISAO is making measurements of the physical, chemical and optical properties of the aerosols in the marine atmosphere.

The following is a photo tour of some of our instrumentation

Our aerosol inlet at the top of one of our lab-vans.  Our inlet is aerodynamically designed and has a computer controlled motor to keep the inlet pointed into the wind so the large particles do not impact on the side of the inlet.

Our aerosol inlet at the top of one of our lab-vans. Our inlet is aerodynamically designed and has a computer controlled motor to keep the inlet pointed into the wind so the large particles do not impact on the side of the inlet. Photo: Jim Johnson

This is the inside of one of our aerosol vans with assorted particle counters, and several devices to measure the particle size spectrum.   Photo: Jim Johnson

This is the inside of one of our aerosol vans with assorted particle counters, and several devices to measure the particle size spectrum. Photo: Jim Johnson

Our Cloud Condensation Nuclei Counter, CCNC, an instrument that takes sample air and raises the humidity to various levels that are just above the condensation point, then it measures concentration of water drops that are formed. Photo: Jim Johnson

Our Cloud Condensation Nuclei Counter, CCNC, an instrument that takes sample air and raises the humidity to various levels that are just above the condensation point, then it measures concentration of water drops that are formed. Photo: Jim Johnson

Another activity is to help with the launch of the weather balloons. The radiosonde attached to the balloon measures temperature, relative humidity and pressure. The radiosonde also receives GPS to track its motion as it ascends, so that a vertical profile of the horizontal winds can also be derived.

Preparing the radiosonde for launch. Photo: Jim Johnson

Preparing the radiosonde for launch. Photo: Jim Johnson

A weather balloon is filled with helium and the radiosonde is attached. Photo: Jim Johnson

A weather balloon is filled with helium and the radiosonde is attached. Photo: Jim Johnson

The balloon and radiosonde are walked to the back of the ship's fantail and released.  As the package rises it sends back the data by a radio link to make a vertical profile of temperature, humidity and winds. Photo: Jim Johnson

The balloon and radiosonde are walked to the back of the ship’s fantail and released. As the package rises it sends back the data by a radio link to make a vertical profile of temperature, humidity and winds. Photo: Jim Johnson

Written by Jim Johnson

A Satellite Scientist Visits the Ice, Alaska 2016: Satellites and a Grand Challenge

June 1st, 2016 by Maria-Jose Viñas

By Walt Meier

Walt Meier coring sea ice.

Walt Meier coring sea ice.

May 31, 2016 — The morning sessions this week have been inside in a classroom setting. It’s been like being back in school, which has been quite fun (believe it or not). For the first four days I’ve been a student, but today I got to be the teacher. I gave the class a lab exercise working with satellite data. The “students” went through several days of imagery and calculated sea ice extent, first for the entire Arctic and then for a region around Barrow, Alaska. One of things this showed is that there are different methods to calculate sea ice extent, each with some advantages and limitations, each giving a slightly different answer. No data is perfect, so this variation in the data gives an indication of the uncertainty of the estimate.

One of the reasons for the differences is that the resolution of the satellite data varies, from 25-kilometer (15.5-mile) grid cells down to 1-kilometer (0.6-mile) cells. This makes a big difference in how well we can resolve ice features. The lower resolution data obviously does not provide the detail of the higher resolution, but in turn it has more complete coverage. So there is a trade-off one has to make. For conditions immediately around Barrow, higher resolution is better, but such data is not always available. For the entire Arctic, having complete data is useful, even if the resolution is lower.

The scientists prep to go on their Grand Challenge.

The scientists prep to go on their Grand Challenge.

In the afternoon, we did our last day in the field and it was a “Grand Challenge” activity. Last night, we were challenged by the leaders of the workshop to use what we learned the first four days to come up with a science question and attempt to answer it by collecting data on the ice. We needed to develop a plan and then implement it today. The question we came up with was to try to determine if the ice would break out from the Barrow coast earlier than normal this year. To help answer that question, we realized we needed data from a different site than what we had used the first four days. Field observations are really valuable, but because they are limited to a small area, it’s hard to tell if they are representative of the larger area. During our snow machine morphology activities, the groups noticed that the ice conditions seemed to change as they headed north. The ice seemed more solid and uniform, with fewer ponds.

Out on  the ice.

Out on the ice.

Laying out the sampling line.

Laying out the sampling line.

So this afternoon we set out a new site a couple miles farther north. The ice was quite different; it was more uniform in appearance, with a white crust of large crystals of crumbly ice on top. We found the ice to be about 10 centimeters (4 inches) thicker than at the southern site and more uniform in thickness. That data and other measurements will be put together tonight and tomorrow. Then we’re going to enter that data into a simple model and run the model with typical weather conditions to see when the ice may become thin enough to break up.

An ice core.

An ice core.

Tonight, the workshop organizers, Don Perovich of CRREL and Marika Holland of NCAR, gave a public talk to the community at the Inupiat Heritage Center in town. Don talked about observations of sea ice and how it has changed over the years, both around Barrow and throughout the Arctic. Then Marika discussed climate models and their projections for the future. The room was full of local residents and the community was quite engaged – there were many questions afterward. The residents here know first hand that the climate is changing because their community is already being affected by the warming: the earlier opening of sea ice is necessitating adaption of their hunting practices, lack of ice is allowing more storm surges and coastal erosion, and warming temperatures are starting to thaw the tundra.

A Satellite Scientist Visits the Ice, Alaska 2016: Memorial Day On Ice

June 1st, 2016 by Maria-Jose Viñas

By Walt Meier

The Red Team drilling an ice core of sea ice.

The Red Team drilling an ice core of sea ice.

May 30, 2016 — This morning we did another modeling exercise, led by Jen Kay of the University of Colorado. A question a sea ice scientist inevitably gets asked is “so, when is the Arctic Ocean going to become ice free?” I can understand the interest, but answering it is quite difficult. One reason of course is that the sea ice models are not perfect – we don’t know exactly how the sea ice will respond to warming temperatures in the future. But the main reason is that the climate naturally varies from year to year and over many years, just due to randomness in the climate system. Jen and others have found that the natural variation in sea ice is quite large. The implication is that even under warming temperatures, variations in the climate system may result in many years where the extent doesn’t decrease and may even increase for several years.

the Red Team in the classroom.

The Red Team in the classroom.

This means that we can’t extrapolate from current trends to estimate the year ice-free conditions occur because the current trends may well be interrupted by natural variations. It also means that even if we have several years where the extent doesn’t drop, it doesn’t mean the warming isn’t having an effect – it just means the warming effect is overwhelmed, temporarily, by a natural cooling effect. It’s like driving a car down a mountain – eventually you’ll get to the bottom, but on the way there may be many flat spots or even sections of the road that go uphill.

In the afternoon, our group did the sea ice properties activity. This involved drilling a core through the ice and analyzing it. Sea ice is not simply frozen water – it is frozen salt water. Although most of the salt escapes during the freezing process, some salt gets trapped in the ice in briny pockets of very high salinity water. Over time, these pockets begin to drain (especially during the summer melt), leaving little channels within the ice. In the core, we noticed the brine already starting to drain after we lifted it out of the hole. These brine pockets are important in determining how the ice melts and interacts with the ocean.

Slicing a sea ice core.

Slicing a sea ice core.

A section of the sea ice core.

A section of a sea ice core.

We also measured the salinity and temperature in the water near the base of the core. The water was near freezing throughout, as expected. But the salinity was quite low just beneath the bottom of the ice. Normally, the ocean salinity should be around 30 ppt (parts per thousand), but below the ice, the salinity was only about 2 ppt. This is because the fresh surface melt water was draining through the ice. Several centimeters lower, we saw the salinity increase rapidly to near 30 ppt.

Today was Memorial Day, so it’s worth noting that Barrow has a long history of being involved in defense activities. We are staying and working at the Naval Arctic Research Laboratory, which as the name implies was a military research station. We can also see nearby the DEW (Distant Early Warning) Line station, which was an early warning defense system to detect ballistic missiles that could’ve been launched by the Soviets. The soldiers that served in the DEW Line stations were literally on the front lines of the Cold War. So it seems appropriate to be here in Barrow on the day honoring those that have served and made the ultimate sacrifice for their country.

Notes from the Field