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Beaufort Gyre Exploration Project 2016: Searching for Sea Ice: More Motion In The Ocean

September 27th, 2016 by Maria-Jose Viñas

By Alek Petty

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My journey up to the ship went smoothly and I even had time to observe the Northern Lights (Aurora Borealis) in full bloom during our overnight layover in Yellowknife (in the Northwest Territories of Canada). The following day, a Canadian Coast Guard helicopter transferred us from Kugluktuk airport onto the ship, and after another day spent refueling and replenishing the boat, we were finally on our way to the Arctic Ocean.

The Northern Lights.

The Northern Lights.

The Louis S. St. Laurent ice breaker.

The Louis S. St. Laurent ice breaker.

I actually spent the first two days of our polar expedition sat out on deck, enjoying the sunshine and views over the Amundsen Gulf. In the distance I could just about make out the mouth of the Mackenzie River delta – a key outflow of fresh and mineral rich river runoff into the Arctic. This shelf sea region is rich in wildlife, including beluga whales and even narwhals. We looked out eagerly, but only spotted a couple of lowly seals in the distance. Maybe on our way back we’ll have more joy.

On Saturday morning, we emerged into the Arctic Ocean proper —the Beaufort Sea! — where conditions were a bit less serene. In fact, one of the consequences of the diminished Arctic sea ice cover over the past decades has been an increase in Arctic Ocean waviness, as the lack of sea ice enables winds to more effectively whip up the ocean. Arguably one of the most distressing impacts of climate change for us unhardened scientists.

Despite the continued lack of sea ice, the water sampling exercises have begun in earnest. At each research station (a virtual station if you will, we just stop at a predetermined location in the ocean) a large metal carousel with various water samplers attached —a rosette, as we call it— is released, profiling the water column as it sinks to the bottom of the ocean, before being hauled back up to the ship for analysis.

A rosette deployment.

A rosette deployment.

There are around 50 stations in total that we plan on hitting during this expedition. The various scientists on board all have their own things their looking for in the water —plankton, bacteria, alkalinity, dissolved inorganic/organic carbon, micro-plastics (yep, they make it to the Arctic Ocean too), etc. You name it, we’re sampling it.

One of my tasks, along with Japanese scientist Seita Hoshino, is to profile the water column in-between theses stations using XCTD (eXpendable Conductivity Temperature and Density) probes. XCTDs provide a quick and cheap (well, about $800 per probe, so not that cheap) real-time analysis of the temperature and salinity of the water column while the ship is moving. I’ll try and show you an example profile in a later blog post.

We’re hoping to hit some ice soon, as for us ice observers there’s not a whole lot for us to get really excited about yet. It’s quite the contrast to the cold, icy conditions of my 2014 expedition thus far…

 

Beaufort Gyre Exploration Project 2016: Searching for Sea Ice: The 2016 Beaufort Gyre Exploration Project: Searching for Sea Ice

September 20th, 2016 by Maria-Jose Viñas

By Alek Petty

Your blogger, Alek Petty, out on the ice during the 2014 Joint Ocean Ice Study research expedition, with the Louis S. St. Laurent in the background.

Your blogger, Alek Petty, out on the ice during the 2014 Joint Ocean Ice Study research expedition, with the Louis S. St. Laurent in the background.

Hello and welcome to my new blog. I’m Alek Petty, a sea ice scientist at NASA’s Goddard Space Flight Center, currently making my way to the northern coast of Canada (a small town called Kugluktuk) to embark on the 2016 Joint Ocean Ice Study (JOIS) – a research expedition around the Arctic Ocean’s Beaufort Gyre. The Beaufort Gyre is a slowly-rotating icy body of water north of Alaska (see map), which covers an area roughly ten times the size of Lake Michigan and stores a significant fraction of the Arctic Ocean’s freshwater.

Cruise tracks from previous JOIS expeditions during 2006-2014 and the sea ice concentration around this year's summertime minimum extent on Sept. 10 (from NSIDC).

Cruise tracks from previous JOIS expeditions during 2006-2014 and the sea ice concentration around this year’s summertime minimum extent on Sept. 10 (from NSIDC).

The expedition I’m going to be on has occurred every summer since 2003 – coinciding with the Arctic annual sea ice minimum, which typically happens in September – providing us Arctic scientists with a unique opportunity to monitor this harsh, but climatically significant region. The goal of these expeditions is to better understand the Beaufort Gyre’s circulation, freshwater content, water mass properties and biota distributions. I’ve been lucky enough to be invited on my second expedition to support this year’s planned sea ice observations.

We will be taken around the Beaufort Gyre by the Louis S St. Laurent, a Canadian Coast Guard icebreaker specially designed to smash its way through the sea ice covered oceans (sea ice can be several meters thick in places). About a week ago, we observed this year’s sea ice minimum, which tied 2007 for the second lowest on record. The Arctic sea ice declines over the past decades have meant yachts and even a luxury cruise liner (with the aid of an icebreaker, they often leave that bit out in the news stories) are now navigating through the southern Arctic Ocean, including the newly opened Northwest Passage  – made famous by Franklin’s failed traverse back in 1845 (when the ice was a lot thicker) and commemorated in this heartfelt tune  by Canadian folk singer Stan Rogers.

While the diminished Arctic sea ice cover has made navigation easier than it used to be, especially for icebreakers, one of the primary objectives of our expedition is to deploy buoys into the ice that can collect measurements of the sea ice-atmosphere-ocean system as they drift through the Arctic Ocean (ice-tethered profilers). One of our initial goals will therefore be to search for sea ice thick enough to ensure that the ice isn’t going to melt out any time soon. One of my primary activities over the next few weeks will be to observe the extent and magnitude of sea ice freeze-up as we make our way north, the days begin to shorten, and the temperatures start to drop.

I look forward to giving you a better overview of what the trip is all about in future blog posts (we’re not just scouting for polar bears, promise), including some background to all the various scientific projects being undertaken. Stay tuned!

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.

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