Monday, November 4, 2013
Oak Ridge National Laboratory (ORNL) held their annual Fall Festival on Friday, November 1, complete with live music, food, and various arts and craft displays. The laboratory used this event to also unveil two science education trailers – one from the Neutron Sciences Directorate and the other from the Energy and Environmental Sciences Directorate (EESD). Both trailers were designed to take cutting-edge science from the laboratory to elementary, middle, and high school students. The Fall Festival provided a great opportunity to showcase the trailers and their scientific displays to ORNL staff before taking them on the road.
Since Kathy Huczko, technical project manager for NGEE Arctic was a member of the team that designed the EESD trailer, we volunteered to set-up a display that would provide an opportunity for students of all ages to gain first-hand experience with frozen soils or permafrost from the north of the Arctic Circle. The “Arctic in a Mason Jar” display was specifically developed with the idea that students would learn where the Arctic was located (i.e., a long ways from where they live), how field scientists obtain permafrost cores, and how laboratory researchers measure greenhouse gases (e.g., carbon dioxide and methane) that are produced from thawing permafrost. I was fortunate to have Taniya Roy-Chowdhury help put this display together and then have her talk people through the various aspects of the display. Taniya participated with our team last April in coring samples from the Barrow Environmental Observatory (BEO), outside Barrow, Alaska. She is also doing the laboratory research as part of her post-doctoral studies at ORNL so Taniya had no trouble conveying the underlying science to people in way they could easily understand. Feedback was positive and we had a great time showing everyone this unique aspect of the project.
Taniya and I will take our experience with ORNL staff and continue to modify the display to best interest students in topics that are relevant to Arctic ecosystems. Taniya and I agreed that we want to make science fun and informative for everyone regardless of age. Based on our experience at the Fall Festival, we took a positive step in that direction.
Monday, October 28, 2013
Despite the cold (and overly ambitious) days of fieldwork in Barrow, the consensus among LANL’s hydrology and geochemistry research team is that our 2nd Synoptic Sampling Campaign in September 2013 was a huge success! Our field crew consisted of a highly motivated and hard-working team from LANL including: Lily Cohen (post-bac, and research superwoman); Garrett Altmann (post-masters, and GIS/remote sensing guru); Marvin Gard (staff, and world class innovator/inventor); and Heather Throckmorton (postdoctoral researcher, and isotope geochemist and enthusiast).
The goal of our research is to assess isotopic and geochemical tracers to infer hydrologic processes, and vertical and lateral movement of carbon across the broader landscape. Our most recent sampling campaign in September 2013 has been an extension of a previous campaign in July 2013, during which we established 17 sites across the broader landscape (both inside and outside the BEO) to collect water samples for analyses. Our sites were initially selected by looking at satellite images of the BEO and surrounding region to identify main drainage channels and outlets from different aged drained thaw lake basins (DTLBs), as locations that integrate hydrologic signals over larger areas. (see below map)
This September we revisited the same 17 site-locations as in July (please refer to map) in order to identify seasonal changes/variability, with the thawing of frozen soils throughout the summer, and corresponding deepening of the frost table.
During our most recent trip this September, we noticed several clues supporting seasonal differences in hydrology relative to July conditions. Our first clue, as expected, was the significant deepening of the active layer as we measured the depth to the frost table at all of our sites. This presumably has significant implications for subsurface hydrologic flow, as deeper mineral rich soil horizons become hydraulically conductive.
Seasonal melt correlating hydrologic processes with geomorphologic features was also really exemplified by a dramatic thermokarst feature that we encountered on our walk in to our site 11 (see map). We previously observed this feature in July as well, but the advanced thawing/melt over the season has promoted slumping on the ridge, and resulted in the interesting feature below.
Additionally, although surface waters can often appear stagnant in the BEO and surrounding region, at a couple of our sites in July we had observed very gentle lateral surface flow and drainage. During our recent trip in September, we noticed visibly greater lateral surface (and subsurface) flow at several of our sites relative to what we observed earlier in the season.
Another notable difference we observed from July to September was an increase in lateral extension of surface water in ponds and drainages at several of our sites. In the vast and hummocky tundra landscape, lateral expansion of surface water would typically be difficult to notice from visible inspection only, with such few distinct reference points in the landscape. However, when we sampled in July, we stationed along the edges of ponded or draining surface waters, marking these locations with bamboo for our return trip in September. During our recent September trip, upon revisiting these locations, we estimated that in many cases the water extended a few meters farther than in July (laterally); and in one larger drainage channel (site 8 on attached map), we estimated lateral expansion of at least 25 meters.
In addition to seasonal variation in hydrology (and significantly colder weather in September!), we’ve noticed some very exciting spatial variation across the broader landscape highlighted by differences in a variety of features across our sites, including: lateral surface hydrologic flow rates; hydrologic conductivity (i.e., the rate we can extract water); depth to frost table; soil properties; and basic field parameter measurements relating to groundwater redox and geochemistry.
In particular, we were excited and encouraged by the outcome of Iron Reduction in Sediment (IRIS) probes that we installed in July, as an indicator of below-ground oxidation–reduction conditions. Dissolution of the ferrihydrite coat on probes showed interesting patterns that varied across sites, which we will quantify with image analyses to better understand redox microsites and variation across the broader landscape (photo below on left). At some locations, IRIS probes developed black speckles of iron sulfide, providing additional insight into below ground biogeochemistry (photo below on right). To our knowledge, this is the first time this technology has been deployed in this type of environment, and we feel that IRIS probes seem promising for improving our understanding of spatial and temporal variation in redox across a range of scales.
We are looking forward to pursuing analyses on water and soil samples back at LANL to better understand how spatial and seasonal variations in hydrology may correspond to and influence biogeochemical processes and C transport. For example, do we see different sources of water spatially and seasonally? Different sources of carbon across the landscape, as organic rich soils thaw throughout the summer and leach or become transported? How do these different hydrologic conditions affect biogeochemistry and redox? Microbial processes? C transport? These are only a few of the questions we are excited to address. So far so good-as our research group, as well as soil and water samples, have all made it back to LANL intact!
Wednesday, July 24, 2013
The LANL team (Jeff Heikoop, Heather Throckmorton, Garrett Altmann, Lily Cohen and Michael Hudak) continues its synoptic survey of water isotopes and chemistry to understand hydrologic pathways and transport in the BEO and surroundings. This year, our focus has shifted from the polygon scale to larger drainage systems with particular emphasis on outlets from interlake areas and different aged drain thaw lake basins. We are taking samples from surface water, the uppermost part of the active layer (0-4” from surface), and the active layer at the frost table (~11-16”) at 15 locations. Sampling at the frost table has proven particularly difficult so we have employed arrays of rhizons to obtain sufficient water while minimizing disturbance (rhizons make a hole only about a finger’s width wide and can be removed immediately after sampling) (Photo 1). The team also got to try out a system for filtering water samples through syringe filters (as small as 0.2 microns) aided by an electric caulking gun. This has saved us hours of tedious and tiresome effort. Our thanks to Marvin Gard whose ingenuity continues to amaze us!
The team is also testing Iron Reduction in Sediment (IRIS) probes to see if these might be a simple and cost-effective way to monitor redox changes on the broader landscape when collection of subsurface water samples may not be practical. These probes consist of PVC coated with a ferrihydrite paint (photo 2). Under reducing conditions iron on these probes will partially dissolve. The amount of dissolution can be quantified by image analysis and related in a semi-quantitative fashion to redox conditions in the sediment. IRIS probes have been approved by the EPA for demonstrating the presence of reducing soils for wetlands delineation. We are deploying these probes adjacent to our rhizon arrays so that we can compare out chemical results (a snapshot in time) to the time integrated signals provided by the IRIS probes, which will be pulled in September. Image analysis will employ LANL’s GENIE technology.
In addition to synoptic survey activities, Liz Miller of LANL has also joined the team to perform a high-resolution differential GPS survey of troughs and flooded low-centered polygons to fill in gaps in LIDAR data. This data will provide sub-centimeter elevation profiles for improved hydrologic modeling of the site (photo 3).
After rigorous days in the field, field team leader Heikoop was particularly impressed that his younger colleagues decided rooms in the Herman House should be segregated based on age with no doubt as to which room he belonged. He also wants to thank Cathy Wilson for arranging to have high caliber athletes, including a champion ironwoman and world-class skier on the trip for him to keep pace with. Fortunately everyone has provided plenty of calorie replenishment back home at ‘camp’ with their array of culinary talents.
Photo 1: Rhizon array in ancient DTLB.
Photo 2: Mike Hudak holding IRIS probes prior to deployment in a young DTLB to the south of the BEO.
Photo 3: Liz Miller performing high-resolution GPS surveying.
Friday, July 19, 2013
The NGEE Arctic team takes a lot of pictures during their stay in Barrow. Most relate to their science, but a few simply reflect the unique nature of life on the North Slope of Alaska. While I certainly do not see all pictures taken by people when in Barrow, I do see enough to post my favorite ones from this past trip.
The first "pic of the trip" was taken by Lily Cohen. Lily is from LANL and snapped this picture of jelly fish one evening as she walked along the Arctic Ocean just a short distance from our Herman House apartment.
The second "pic of the trip" was taken by Garrett Altmann. Garrett is also from LANL and took this mushroom picture one afternoon while collecting water samples from a drained thaw lake basin south of Barrow.
My thanks to Lily and Garrett for capturing these great images of the Arctic.
This past week was a productive one for our NGEE Arctic team in Barrow. July is a busy month for us with more than 20 scientists, staff, and students working at our field sites on the Barrow Environmental Observatory (BEO) and to the south across a series of drained thaw lake basins. The weather was good early in the week, but it turned foggy with a light rain especially in the last few days. As the winds died down and air temperatures rose, the mosquitoes came out with a vengeance. Deet and bug jackets were definitely required if you were going to make working in the field bearable.
Although the weather could have been better, this was the week that several NASA program office staff would visit Barrow. I picked up Peter, Dan, Libby, and Leanne, as well as University of Maryland professor Eric Kasischke from the airport on Monday morning. They had traveled to Barrow in order to familiarize themselves with tundra ecosystems of the North Slope of Alaska. They also wanted to see first hand the many scientific facilities in town and to visit with UMIAQ, the logistical provider who supports our NGEE Arctic project.
We spent two days touring the Department of Energy, Atmospheric Radiation Measurement (ARM) climate research facility; the NOAA CMDL facility; the Barrow Arctic Research Center; and the BEO where we and others have field research sites. This gave Peter, Eric, and others a good overview of the long-term monitoring activities in Barrow and the types of science being conducted at these facilities and the BEO. My thanks to everyone who helped make our discussions productive, especially Karl, Eric, Jon, Brower, Laci, Araina, and Uinniq, all from UMIAQ. And my thanks to Walter and Marty for tours of the ARM and NOAA facilities, respectively. Despite the hordes of mosquitoes, it was a good visit...one that was both enjoyable and met the goals of the trip.
Tuesday, July 16, 2013
Scientists can be creative! A perfect example of this creativity reveals itself when the NGEE Arctic project needs to collect aerial images of ice-rich polygons on the Barrow Environmental Observatory. We could rely on high-resolution pictures from aircraft, but given the small area of our intensive site that would be expensive. Unfortunately, the resolution of satellite imagery is too coarse. Why not just hang a camera from a kite? We saw this used quite effectively last year by Craig Tweedie and his students from UTEP, so we thought we'd give it a try! That's what Baptiste Dafflon and Craig Ulrich (both from LBNL) did yesterday after testing the concept several weeks ago in California.
Baptiste and Craig have conducted geophysical surveys on the BEO now for two years. The goal has been not only to understand sub-surface properties like ice content and size and distribution of ice wedges, but also to relate those characteristics to surface properties including topography and the fraction of the landscape seasonally inundated by water. The team needed, however, some way to correlate patterns of inundation to variation in sub-surface properties. The kite seemed like a worthwhile approach to try. It is too early to comment on the overall utility of the idea, but an initial look at the aerial images suggests that the quality of pictures makes this kite-based approach a reasonable one for our purposes.
Baptiste and Craig, along with others on the NGEE Arctic team, plan to replace the camera with a spectrometer in hopes of using spectral signatures to identify water distribution and landscape patterns of inundation throughout the season. Then it will be possible to begin drawing correlations between surface and subsurface characteristics and using those insights to improve multi-scale models of terrestrial ecosystems.
Monday, July 15, 2013
It seems like my LANL colleagues have instituted a new tradition when in Barrow - Sunday is apparently taco night! Just exactly how this started is uncertain, but Garrett Altmann and others staying in the Herman House apartment, opened their doors to all participants in the NGEE Arctic project for dinner. Garrett and Heather had gone to the store earlier in the day and bought all the necessities for a Santa Fe style mexican dinner. Garrett took over the kitchen with others helping prepare soft and hard shell tacos complete with a spicy meat sauce, tomatoes, lettuce, and avocados. Team NGEE Arctic has a chef that prepares a pretty awesome menu...
Dinner attracted nearly 20 hungry scientists, staff, and students from all 4 of the national laboratories and several of our university partners. The food was great and there was a lot of discussion as people got to know each other. I heard a lot of comments like "What do you do?" and "Oh, I sent you an email...". It was a fun night that continued until midnight. Then someone said "Hey, field work starts at 8:00am!" and there was a realization that everyone better get some sleep!
It was a fun night. Herman House has a 'no shoe' policy so my favorite scene of the night was our front entry way. Shoes were everywhere and a good time was had by all.