Monday, September 1, 2014

Living in Barrow…Herman House

A few people have asked what it’s like to live in Barrow. Being the northernmost city in the United States you can guess that it is different from life in the lower 48. However, we have great logistical support from UMIAQ and as a result we typically have everything we need including vehicles and housing. Our team, especially when we have large field campaigns, is usually distributed between 3 apartments in town; two apartments along Boxer Street and the Herman House. All of these locations are close to the gas station, grocery store, etc. This week Larry, Go, David, Baohua, Ziming, and I stayed at the Herman House; a two bedroom house that sleeps 8; nine if you count the futon in the living room. The two bedrooms have bunk beds and can get a little crowded. Everyone, however, seems to find a spot and can operate pretty effectively despite the close quarters. Internet connections are slow, so it helps that people are patient. It can get a little hectic when everyone returns from the field with boots and jackets, especially after a wet day of research like yesterday, drying in various rooms throughout the house. We have a nice kitchen where we can prepare meals and even a washer and dryer. Most people are finding that thanks to these resources, research trips to Barrow can be enjoyable and everyone seems to like the comradery.






Sunday, August 31, 2014

Water, Water Everywhere…But Where Does It Go?

One of the organizing themes of the NGEE Arctic project is hydrology. It is important both for our field and laboratory measurements and especially for our modeling. We are exploring the question of how water distribution across polygonal landscapes will be impacted as permafrost thaws and topography changes due to melting ground ice and ice wedges underlying polygons. Our hydrologists and their modeling colleagues are finding that a key uncertainty in determining water distribution, in addition to topography in these low gradient environments, is the saturated hydraulic conductivity (Ksat) of soils. Knowing Ksat allows us to better understand the movement of water through saturated media and facilitates accurate modeling of water flow in soils. Modelers on our team need this information for the parameterization of our fine-scale models of low- and high-center polygons and for use in our global land surface models.

Today Cathy, Go, Larry, and I left our apartment and stepped out into the windy, cold, and unusually rainy weather. It was slightly annoying at the time, but surely the weather would get better right? As we pulled sleds full of our equipment to the field we soon realized that the sun was not going to appear, that the winds were not going to subside, and that the rain was not going to stop. On the contrary, this was going to be (not withstanding mosquitos) one of the more miserable days on the tundra that I have experienced in the last three years.
 
Once at the field site Cathy unpacked our Guelph Permeameter that she had purchased some time ago from Soil Moisture Equipment (Santa Barbara, CA). The equipment can be transported, assembled, and operated presumably by one person. However, we found that in rainy weather with winds upwards to 20 mph that two people were needed to stabilize the unit, position the tripod, and get it ready for operation. Once assembled, the permeameter enabled measurements of Ksat to be determined in 35 minutes to an hour. Although all the calculations still need to be completed, it is clear that Ksat values for the silty soils commonly found across our field sites on the Barrow Environmental Observatory (BEO) are low. This means that water movement, especially lateral movement, is very slow. Our team has noticed this in trying to collect samples for water chemistry, etc. It is simply difficult to get water from these soils. We think that once incorporated into models, the consequences of low Ksat – now that we have direct measurements – will become evident in the distribution of water across the landscape and the cascade of other processes of biogeochemistry and vegetation dynamics. We should know more about this before too much longer… 




 

 

 

Saturday, August 30, 2014

Available Forms of Nitrogen for Tundra Plants and Microbes…

Yesterday was a productive day for all NGEE Arctic teams working on the tundra. Today our group left the Herman House apartment with a couple of goals. One was to complete surface and pore water sampling for geochemistry; another was to continue vegetation resurveys for the purpose of fine-scale mapping of plant functional types (PFTs) across polygons. Mallory and I also wanted to finish sampling of soils that she began two days ago for analysis of nitrogen availability. While Mallory has not yet developed the full scope of her PhD studies, she is interested in better understanding the interplay between soil organic matter decomposition and the forms of nitrogen ultimately made available for plants and microbes. More specifically Mallory would like to combined advanced analytical methods with some aspect of plant and microbial biology, and therein characterize the pool size and diversity of low molecular weight (LMW) nitrogenous compounds in soils. There is a considerable amount of published literature on nitrate and ammonium availability in tundra soils, but LMW compounds that can be used by plants and microbes as a source of nitrogen are also important. However, they have not been fully characterized. Working with Bob Hettich and Rich Norby at ORNL and as a student through the Bredesen Center for Interdisciplinary Studies and Graduate Education, Mallory has the opportunity to merge powerful mass spectroscopic approaches (MALDI and electrospray ionization sources) and field ecology, into a single program of study. But before she can do this, Mallory needed to obtain a range of samples from the Barrow Environmental Observatory (BEO) so she could conduct preliminary studies to refine her techniques and then, equally important, the questions that Mallory would like to tackle will also need to be developed. She identified plots within low- and high-center polygons and excavated a small monolith of soil from the upper active layer. She did this at a number of locations making sure that she had adequate replicates and samples for areas that supported the growth of several different plant species. This way Mallory can assess her early work in terms of variation in nitrogenous compounds due to topographic location and species composition. Once samples were collected they were labeled, placed in plastic bags, packed into a cooler, and will be shipped to ORNL later this evening. Mallory will be busy during the coming months and it will be interesting to see how her research develops both with regards to fundamental science and integration of that knowledge into models.









Friday, August 29, 2014

Geochemistry of Methane Formation in Surface and Pore Water Samples…

Today we had 15 people working on the Barrow Environmental Observatory (BEO). Researchers from three DOE national laboratories, the University of Alaska, and scientists from China, Japan, and Germany were collecting data on various topics; soil carbon dynamics, hydrology, and energy balance. It is always rewarding to see this many people working on so many integrated components of the NGEE Arctic project.


David, Baohua, Mallory, Ziming, and I left our apartment in Barrow shortly before 8:00am and stopped by the Barrow Arctic Research Center (BARC) and our storage room in Building 553 before heading to the field. Once we made the 2 km hike to our field site, Baohua and Ziming got busy collecting surface and pore water samples. They used a combination of techniques to obtain water samples from various depths in the soil using macrorhizons, etc. These were inserted into the soil of low- and high-centered polygons yesterday, placed under modest suction, and by this morning had accumulated 40 to 50 cubic centimeters of water. It was necessary to filter the samples to remove suspended sediments and then Ziming and Baohua analyzed them in the field for electrical conductivity, pH, temperature, and concentration of ferrous iron. One of the primary objectives in collecting these samples is to better understand the process of methanogenesis. Methanogenesis is the formation of methane, a potent greenhouse gas, by microbes known as methanogens. These microbes, under anaerobic conditions, use ferric iron as an electron acceptor. This gives rise to ferrous iron which indicates anoxic conditions that may support methanogenesis. Data from the work of Ziming, Baohua, and David will be integrated with field and laboratory experiments to better understand the geochemical controls on methane formation. Improvements in how models represent this important process are one outcome of this research and an important goal of the NGEE Arctic project.








Thursday, August 28, 2014

Early Career Scientists Contribute to NGEE Arctic…

The NGEE Arctic project has been fortunate over the last three years to host a number of post-docs, and PhD and MS students. These include Heather, Lily, Michael, Lydia, Zach, Baptiste, , Shan, Carolin, Melanie, Ingrid, Ali, Chandana, Mark, Andy, Jonathan, Jenny, Santonu, Xiaofeng, Victoria, Taniya, Elizabeth, Nathan, Biao, Andy, Mark, Andrew, and Ben to name just a few. I want to thank all of them for their dedication and for their field, laboratory, and modeling contributions to the project.

This week we are fortunate to have Mallory Ladd and Ziming Yang join us for this trip  to Barrow as new team members. Mallory is starting her PhD as a student with the Bredesen Center for Interdisciplinary Research and Graduate Education (http://bredesencenter.utk.edu/index.php). This program unites complementary resources at the University of Tennessee and Oak Ridge National Laboratory (ORNL). Mallory is working with both Bob Hettich and Rich Norby to assess forms of organic nitrogen in permafrost. She will be applying various analytical techniques to examine nitrogenous compounds in soil and competition for that nitrogen between plants and microbes. Ziming joined the project as a postdoctoral research associate through ORNL’s Postdoctoral Program (http://www.ornl.gov/connect-with-ornl/for-academia/postdoctoral-programORNL) after a successful PhD program at Arizona State University. While at ASU Ziming obtained his PhD degree in organic chemistry in the Department of Chemistry and Biochemistry. Ziming is working with Baohua Gu and will examine the geochemical controls on methane flux from thawing permafrost. He will have both a field and a laboratory component to his research, as will Mallory. It is hoped that the work of both Mallory and Ziming will allow us to better understand and integrate novel aspects of carbon adn nitrogen biogeochemistry into models.
I will focus on Mallory's and Ziming's specific research later in the week and what they are individually doing while in Barrow while working on the NGEE Arctic project.





 

Tuesday, August 26, 2014

Pic of the Trip…

Our trip to Seward Peninsula is over and, with the exception of Cathy, Larry, and Joel, everyone is leaving Nome. Most people are traveling home; David and I, however, will catch a flight on Wednesday to Barrow where we will meet others from ORNL for a week of field work on the Barrow Environmental Observatory (BEO). This week on the Seward Peninsula has been terrific. Our team always enjoys being together; it’s a great group. Discussions can be wide-ranging when you get this many people together but everyone gets along and we always have a long list of things to do. The drive and the time in the field all contribute in a positive way to our to-do list.

Here are few photos that people contributed throughout the week that did not make it into my evening postings to the blog. The pictures show the lighter side of science and the scenery that was around us all week. I hope you enjoy them. My thnaks to David, Shawn, Cathy, and others for sending me photos. I’ll continue posting to the blog in a few days once we are settled into Barrow. Be safe…
 
 




Monday, August 25, 2014

Interesting Geomorphological Features in the Landscape…

According to Wikipedia, solifluction is a gradual mass wasting slop process, occurring in periglacial environments. It is the slow downslope movement of water-saturated sediment due to recurrent freezing and thawing of ground. The lobes formed through the solifluction process are quite distinctive and easy to see as you drive through the area.

 
We have seen evidence of solifluction at several locations this week and today we took the opportunity to visit one such site on a modest hillslope just 15 to 20 miles outside Nome on the Teller Road. Joel and Eitan spend the afternoon excavating a small section of an advancing lobe trying to better characterize thaw depth, ice content, soil texture, and moisture content. Larry, David, and Cathy took time to collect soil cores from across the lobes and adjacent areas, as well as quantify the spatial variation in thaw depth across the area. Since one of these solifluction features can cover an entire hillslope I took the afternoon to walk each lobe and examine the distribution of water and vegetation along the advancing front. It was clear that the lobes were fairly massive with most of them being multiple meters in height. The advancing faces of these features were heavily colonized by willow shrubs. These shrubs were quite productive and seemed to thrive in areas of physical disturbance. Downslope of the advancing face the soils were saturated and vegetation was largely sedges and forbs. So these geomorphological features created a highly variable environment for vegetation cover. The implications for albedo, energy balance, and the carbon cycle of these solifluction features are unknown, but they represent interesting features in the landscape. While the solifluction process itself may not be of interest to our NGEE Arctic team, the mechanisms that promote shrub expansion are and we will want to return to this and other disturbed areas in order to learn more.