Final thoughts from the tundra...

The last two weeks have been both hectic and rewarding. Larry and I were able to successfully highlight the dynamic nature of Arctic ecosystems for our team of modelers and BER managers.  Upon their departure from Barrow, I was able to get a considerable amount of work accomplished. I collected soil water samples for a collaborator; worked with Bryan Curtis as he logged data using an NDVI sensor for plant cover and productivity; and transported trail mat for my colleagues who visit the field site in September.  I was also able to complete lots of other field, lab, and organizational duties as well. It proved to be a fun and productive week.

My visit ends this afternoon with a final meeting with our logistics provider...UMIAQ. They are in the midst of developing a 10-Year Master Plan for the Barrow Environmental Observatory (BEO) and are asking for input from scientists who either have or are actively working on the BEO. This should be a timely meeting as NGEE Arctic ramps up in the coming months.

Finally, Larry sent a great picture of our team standing atop a large permafrost degradation feature in Barrow. This area was the result of a disturbance several years ago, but it illustrates nicely the processes we are trying to study. On one hand, low-centered polygons represent healthy permafrost conditions; we saw many of these this week. On the other hand, degraded areas can form where permafrost has warmed. This warming can result in thawing of the permafrost and subsequently set up strong interactions with surface hydrology. Thermal erosion can quickly, in a matter of a few years to a decade, drive the formation of these degradation features. As you can see there is considerable subsidence in these areas, the soil dries, and you can get rapid mortality of tundra vegetation. Our NGEE Arctic project wants to understand the natural processes that might also lead to these "features of the future" and represent them in models. We believe this to be a major step towards better understanding critical landscape-scale feedbacks to climate in the Arctic.

Cheers...

Science time...

Now that everyone has left, I'll be spending some time in the field. I have plenty to do and only a few days to accomplish my assigned tasks. I am not alone, however, in that Alistair Rogers is in the field taking photosynthesis measurements; Victoria Sloan is sampling roots; and Margaret Torn has a group that includes Lydia Smith, Bryan Curtis, Mark Conrad, and Melanie Hahn. Mark and Melanie left earlier in the week, but Lydia and Bryan are staying extremely busy. Lydia is taking gas and water samples from across our field plots for CO2 and CH4 flux analysis and for collecting gas samples for 14C determinations. This will give some indication as to the age or lability of compounds that are giving rise to these two greenhouse gases. Lydia and Bryan are also collecting information on soil moisture, as well as collecting water samples for analysis. These individuals are great to work with as they seem to find the same excitement as I do in conducting research in this environment.

My day was spent collecting water samples in collaboration with Ken Williams from the Lawrence Berkeley National Laboratory. Ken is working to better understand the geochemical controls on microbial metabolism. I posted a blog about this effort back in mid-July.

Ken and I will be returning sometime in late September or early October. Today, I am collecting water samples from each of two depths in features representative of centers, edges, and troughs from low-centered and flat-top polygons. These samples will be analyzed for reduced and oxidized forms of iron in water itself and then in the soil or sediments. The collaboration with NGEE Arctic is such that we can provide samples, access to field plots or our transect for other agency or university research. This leveraging of resources with the NGEE project makes good sense as research is, without access to a well-funded project or established infrastructure, logistically expensive and technically challenging.

All good things must come to an end...

Our NGEE Arctic team has had a great week. The ecosystem and climate modelers working on the project, together with ORNL and BER managers, began their introduction to the Arctic in Anchorage and then pressed on onto Nome, Council, and finally Barrow. We have covered a lot of ground...literally. Everyone has learned a lot about Arctic ecosystems and how we intend to study important processes in support of climate prediction.

We reinforced the goals of our project one last time today as the modelers took center stage and explained how model-experiment integration would be put into practice. Peter Thornton began with an introduction of the modeling goals of the project and was followed by brief presentations from Charlie Koven, Jitu Kumar, Chonggang Xu, Scott Painter, and Haruko Wainwright. Charlie focused on advancements that were needed in our ability to model important biogeochemical cycles and permafrost dynamics, while Jitu and Scott focused on the computational needs and requirements for our fine- and intermediate-scale models. It would be at these scales that much of our process understanding would be captured and then lessons learned transferred to climate grid-scale models. Chonggang provided an example of how this might be done by way of improved representation of nitrogen allocation in plants and adding new detail to how plant functional types are defined in dynamic vegetation models at Pan-Arctic to global scales. Haruko completed our presentations by discussing how she was providing spatial data sets for modelers by taking multi-scale data (i.e. remote sensing data and point measurements) and integrating those using Bayesian methods. Her talk focused on geophysical data and how ground penetrating radar, etc. were being combined with LiDAR, point measurements of thaw depth and snow cover to extrapolate important parameters to larger spatial scales.

Knowing that everyone would be leaving either tonight or on the morning flight to Fairbanks and beyond, we ended the day with a group dinner at Northern Lights restaurant. This was one last time to discuss our impressions of Alaska and how the NGEE Arctic project would progress in the coming months. It was great to interact with Mike Kuperberg, Gary Geernaert, Sharlene Weatherwax, and Martin Keller in such an informal setting. My thanks to everyone for taking time out of their busy schedules for this trip. Their input on the NGEE Arctic project is appreciated.

So, for now, this trip is considered a success and we will move forward from here. Our team has done a lot this year and while our season is not over, we certainly will soon be turning our attention to data analysis, interpretation, and comparison of results across the many disciplines involved in the project. We have our NGEE Arctic All-Hands meeting in December before the AGU meetings, so I need to begin preparation for that event.

I stay a few extra days in Barrow for field work and will continue to post updates throughout the week.

Cheers... 

Sunday was a fun day on the tundra

Today was the day we would all go to our NGEE Arctic field site. We had people working on the tundra ready to explain what they were doing as part of the project. First, however, we met in the Barrow Arctic Science Center (BASC) where Mark Ivey and I gave presentations on the ARM program and NGEE Arctic project, respectively. My goal was to provide an overview of the project for our modeling team and BER sponsors, highlighting how measurements were being conducted in support of climate models. Our sponsors have developed the concept of model-experiment integration (or MODEX), we have adopted this concept as a driving force behind the NGEE Arctic project. My presentation, hopefully, made a clear connection between our measurements and our models.

After introductory comments were made and we engaged everyone in discussions, we loaded up the vehicles for a quick trip to our field sites. We walked the 1.5 km to our plots fairly slowly, giving everyone ample time to ask questions and stop along the way...there was a lot of both. Larry and Vladimir Romanovsky, a permafrost scientist at the University of Alaska Fairbanks, did an outstanding job of fielding most of the questions. The concept of how low- and high-centered polygons form is a difficult one to convey. This is probably due to the challenges of visualizing the dynamics that are occurring in the subsurface environment. Nevertheless, by the end of the afternoon, most people had a pretty good idea about how low-center polygons form and how they degrade to form high-centered or flat-top polygons. It was helpful that our field site is rich in all forms of polygons, making it a little easier to visualize the processes involved in landscape change or evolution. This was a major source of discussion during lunch.

Most of the afternoon was spend at the NGEE Arctic site, but we did managed to break away to tour the ARM facility in the late afternoon. This is an outstanding collection of instruments that together are providing improved understanding of cloud formation and characteristics of cloud formation. The ARM site is also home to an eddy covariance system, operated by Margaret Torn from LBNL. Margaret is a member of our NGEE Arctic team, she and her colleagues have instrumented this tower with the capabilities required to measure CO2 and CH4 fluxes from the landscape. While not part of the NGEE Arctic project, the system operated by Margaret Torn is a good complement to the fluxes we hope to measure across several types of polygons in future systems.

In retrospect, today was a good day for everyone on our trip.  I think our team of modelers was highly engaged and, when possible, were talking to the field scientist and to each other. There was also considerable discussion with BER managers and Martin. This was good to see, it really contributed to the overall value of this trip to the project.

So, it was a long day, but a good day. We spent the rest of the afternoon and evening visiting the ARM site and having dinner at the local tribal community college. Discussions were lively and it was a great way to end the day. We took the opportunity to drive everyone out to a location near Point Barrow. On our return trip along the Arctic Ocean, we just happened to come across two massive vehicles being examined by what I understand is the Coast Guard. The Coast Guard is interested in sea ice-land rescue operations and these vehicles might be suitable. They looked to be fairly sophisticated tracked vehicles that could be quickly deployed in harsh conditions.

Tomorrow is our last day in Alaska and it was good to know that we ended today on such a high note!

NGEE Arctic team flies north for a birds eye view of Alaska

A quick checkout from our hotel and we were off to the airport. Larry and I had to shuttle people and luggage, but 30 minutes later everything was complete and we were ready to focus on a flight that would take us from the Seward Peninsula to the North Slope of Alaska.

Our trip from Nome to Barrow was chartered with Hageland Aviation Services. This was the same company we used last year and we were really happy with the experience. We were met at the gate by our pilot Jim and co-pilot Sterling. After a short safety briefing and check on the weather, we were escorted onto the tarmac and our Cessna Model 208B Caravan. The aircraft holds 11 and we filled every seat.

Larry and I had arranged for a flight that would take us from Nome back out towards Council. We wanted our team to see from the air what they saw yesterday on the ground. Because our team on this trip is composed mainly of modelers, there is a keen interest in having them see the different scales at which patterns and processes emerge across the landscape. Yesterday, we stood in thermokarst formations on the tundra, areas where permafrost is beginning to thaw and degrade. Today, our team is getting to see those same formations, but from a larger perspective. What they see are interconnected networks of features that snake their way across the tundra. These thermokarst features are representative of the dynamics we plan to measure and then include in advanced ecosystem and climate models in the coming years. One can easily envision how thawing of permafrost and subtle shifts in local-scale hydrology can drive important changes in vegetation dynamics, biogeochemistry, and then feedbacks to climate through influences on CO2 and CH4 exchange with the atmosphere.

After flying over Council, we headed north. One of the first things we noticed was the disappearance of trees, tall shrubs, and eventually even small shrubs were restricted to stream margins. The presence of patterned ground or ice-wedge polygons also became much more obvious. Again, these can be subtle features when on the ground, but they are very evident from the air. Haruko (from LBNL) has been quite diligent in taking notes and I saw that, while flying, she had sketched these polygons in her notebook. I am very impressed with how Haruko, and in fact a number of our team members, have committed themselves to learning as much as possible about Arctic ecosystems during this trip. Larry has been outstanding in his willingness to explain all he can to our team. He has a knack for translating complex topics into simple explanations and then layering on details as appropriate. Larry provides a great example of someone who is willing to transfer his knowledge to others and how that ability is such a benefit of the larger project.

After stopping for fuel in Kotzebue, we turned east towards Selewik. We visited this site last year and it was another tremendous visual of how dynamic the landscape can be in Alaska. This larger catastrophic thermokarst occurred several years ago in response to a disturbance along the Selewik River. This exposed permafrost to prevailing air temperatures and the area has been degrading ever since; expanding into the surrounding landscape. The pictures can be dramatic.

Our last stop of the day was an isolate runway at Ivotuk. We landed there after first crossing the Brooks Range. As expected, they were a rugged and remote range of mountains. Ivotuk is a site that Walt Oechel, San Diego State University, has maintained for many years. It is instrumented with a number of sensors and has capabilities for measuring greenhouse gas fluxes as well as other environmental variables like temperature, radiation, and wind speed.

You could not have asked for a better day to make this flight. The sun was out, but not the mosquitoes. We covered a lot of ground and compressed in time the transition of ecosystems from boreal forests to high Arctic tundra. Flying is such a great way to see all of this in a short period of time. It serves to reinforce the dynamic nature of these ecosystems along with the opportunities and challenges of what our team is committed to ding in the NGEE Arctic project. Along the way, we also managed to see a lot of caribou and one lone moose. Peter and a few others were lucky enough to spot 6 Grizzly bears; on each of two occasions there was a mother and 2 cubs. So it was deemed by all to be a successful day.

We landed in Barrow where Victoria and Alistair picked us up and handed off keys to the van and a truck. These will be handy as we shuttle people in and around town while touring our NGEE Arctic field sites and those associated with the Atmospheric Radiation Measurement (ARM) facility on the North Slope. That begins tomorrow; right now I'm anxious to get to our assigned housing and then to dinner. A soft bed, futon,  or couch would also be appreciated...cheers!

NGEE Arctic team makes its way to Council...

Everyone was ready bright and early this morning to make the 75 mile drive to Council. The road has been undergoing repairs, so we figured an early start would make up for any travel delays we might encounter. Fortunately, there were none and we arrived safely in the vicinity of Council by 10:30am. We did make several stops along the way. One especially nice one was in the foothill as we rose above the coastal plain and crested a pass. It was here that Larry introduced members of our modeling team to permafrost and the use of a long slender rod to determine thaw depth. Thaw depth is a function of air and soil temperature where ground frozen during the winter slowly thawing as air temperatures rise and the summer months progress. Although the ground at this location was admittedly rocky, we could still easily probe to determine active layer thickness. In most cases, it was only 35 to 40 cm; 12 to 15 inches maximum.

Later in the morning, we took the opportunity to dig a small hole in the tundra and examine it for organic matter, live roots, and mineral soil. It was a good illustration for our modelers as it showed carbon-rich soils in these permafrost environments.

We descended down the road onto the tundra that occurs in and around the Council area. Larry had worked in this area for many years and was familiar with the general landscape and how the area was dotted with a mix of short and tall shrubs, open woodlands, boreal forests, and then tundra. We spent the morning and into the afternoon looking at various features in the area including thermokarst, areas that form due in part to thawing permafrost. These are interesting features in that the tundra undergoes local subsidence, ponding of water, and then (with time) networks form and water moves laterally across the landscape. This process is poorly understood and not well, if at all, represented in models. We hope to add that level of understanding to models and it was, as a result, great to have the modelers on our team see these areas. There was a great deal of discussion and I believe that everyone came away with a much better appreciation for how dynamic these landscapes can be, especially in a climate that is characterized by warming temperatures.

Our lunch was enjoyed along Bear Creek just outside Council. It was a good opportunity to relax in what was surprisingly warm temperatures. We had a chance to talk about the morning activities and then highlight what was yet to come in the afternoon.

After lunch we had the opportunity to visit a near-by research site maintained by scientists from the Korean Polar Research Institute (KOPRI). They had a number of weather monitoring stations, eddy covariance towers for measuring greenhouse gas flux, and then small plastic chambers for measuring very local scale exchange of CO2 and CH4 between plants, soils, and the atmosphere. We had worked with one of these scientists earlier in the year and it was good to finally see their research site.

Although it proved to be a long day of driving and observing landscape dynamics on the tundra, our team had a very positive experience. To make a great trip better we came across sculpture or two outside remote cabins and an old dredge at least 60 miles from Nome. We saw several just like this one during our drive to and from Council. We also had the pleasure of seeing upwards to 100 muskox. They were all a little too far away for my camera but they were massive. I understand that populations of muskox in the Seward Peninsula were once low but are now making a come back. We took a late-day group picture with one herd in the background.

It was a demanding schedule, but nonetheless one that allowed us to see and do a lot of different things. Saturday we continue the learning experience as our team of modelers and Martin travel from Nome to Barrow. Should be an equally great day!