Tuesday, November 11, 2014

Pic of the Trip…

The NGEE Arctic team has enjoyed a great 10-day trip to Barrow. We accomplished everything that we had planned and did so under constraints of short days and low temperatures; but that’s the Arctic. Our team has plenty of activities for this winter, including the quickly approaching Fourth Annual NGEE Arctic All-Hands meeting followed by strong participation in the American Geophysical Union (AGU) meeting. Both of these will be in San Francisco. I look forward to seeing many members from our team during those two back-to-back meetings.

For now, however, we close out another field season in Alaska. Those of you familiar with our blog know that I often save a particularly appealing or amusing picture as our “Pic of the trip”. This week there were several that I personally enjoyed including the sun dipping below the horizon as I landed in Anchorage and the sunrise one morning on the Barrow Environmental Observatory. My favorite, hands down, was one taken of Ori as she enjoyed Häagen-Dazs ice cream one afternoon on the tundra. This might not seem too odd except it was -17F at the time. Ori commented that unlike the summer, she has no trouble keeping her ice cream frozen during winter trips to Barrow. I do recall seeing an ice cream bar often stuck into a nearby snow drift while she took flux measurements all week! Thanks Ori…

Collecting Data Through Long, Cold Winters…

Researchers working on the NGEE Arctic project are physically on-site between later May and Early November. So, data collection and equipment maintenance proceeds without too many delays or interruptions. Once the days get short and the temperatures plummet, data continues to be collected but it requires considerable automation, especially of the sophisticated electronics we have deployed at the site. Now is a good time for Bryan and Keith to upgrade some of our sensors and instruments, and begin to prepare for the long, dark winter ahead. Today was spent installing a couple of new electronic control panels that house multiple marine cycle batteries and an uninterruptable power supply. This set-up will be sufficient to run our electrical resistivity tomography (ERT) transect, our networks of soil temperature and moisture sensors, and two cameras. One is positioned along the ERT transect and the other is installed as part of the PhenoCam, an ecosystem phenology web camera network run by Andrew Richardson (Harvard) and others. Although the cameras will not capture useful images for 4 to5 months, they will be up and running via remote operation during critical periods of transition including snowmelt and vegetation regrowth. Bryan and Keith worked hard this trip to get these upgrades in place, so my thanks to these talented and patient members of the team.

More Time on the Tundra...

The NGEE Arctic team has been challenged this week to complete all our tasks between sunrise and sunset. The short days, less than 5 hours, mean that we are spending another day collecting permafrost samples and measuring CO2 and CH4 fluxes. We headed out to our field sites today before sunrise thanks to good organization yesterday and UMIAQ having the snow machines checked out and full of gasoline. The trip only took 30 minutes and just as the sun rose above the horizon, John had located our first sampling location for the day. He also used the dGPS to locate a few measurement sites for Ori. One of our goals in measuring the flux of greenhouse gases from polygons on the North Slope of Alaska is to better understand the role of spatial variability in CO2 and CH4 flux rates related to hydrology, geochemistry, and vegetation. These are complex landscapes with a diversity of low- and high-center polygons that dot this area of Arctic coastal plain. So, our measurement sites, which easily total more than 100, are distributed across center, rims, and troughs. These features are now frozen and most are now covered with snow, but throughout much of the year these microtopographic features present a wide range of soil and environmental conditions that contribute to observed rates of greenhouse gas fluxes. Our team needs this information to better understand what controls fluxes and how that knowledge can then be used to improve climate predictions. We are collecting other data from the permafrost cores under controlled laboratory conditions to evaluate observations in the field. This multi-scale aspect is unique to our project and provides an opportunity to draw connections between laboratory and field estimates of flux. Ori and other colleagues on the project have literally collected thousands of flux estimates in the field over the season. Once back in the office these data will need to be analyzed and results interpreted. Once analyzed the data nd resulting insights can be shared with the modelers on the project for incorporation into their simulations.

Friday, November 7, 2014

Organize and then Out to the Tundra…

This morning we met at our storage building and set about organizing materials and supplies that we either brought in from the field yesterday or that had accumulated throughout the summer. Bryan and Keith shouldered most of the burden, but made good use of the time to also make sure that they had everything they needed to update the electronics and controls for the tram. We brought back the unit that powered and controlled the automated tram earlier in the week and now will spend a few days improving the operation and reliability of the system for deployment later in the week. It is great that UMIAQ, our logistics provider, has a lot of floor space where we can spread out and sort through all that we have brought to Barrow.

While Bryan and Keith were busy in the storage area, John, Ori, Naama and I headed out for a day of field research. Once again we relied on snow machines and sleds to transport all our instruments and equipment. Once at our field site we were treated to an amazing sunrise at 10:45am. Compared to the cloudy weather that we have had to date, today was sunny and windy. We quickly got to work. John and I started by collecting permafrost cores while Ori and Naama continued to measure CO2 and CH4 flux from several transects. John and I needed to collect nine cores associated with plots that Lydia (LBNL) is measuring as part of her PhD dissertation research. We were successful in collecting six cores before sunset at 3:45pm. It was interesting to see the upper 10 to 15 cm of active layer soil had frozen already, but that underlying soils down to 35 to 40 cm were still unfrozen. This presented a challenge of getting the cores out of the barrel of the SIPRE, as the soils immediately began to freeze in the SIPRE once brought up into the air. This proved to be an unexpected complication and slowed us down. John and I will need to get the remaining three cores tomorrow. These cores will be shipped back to UC Berkeley where Lydia will be analyzing them for SOM, carbon content, and 14C dating.

While John and I collected cores, Naama and Ori gathered data on CO2 and CH4 fluxes. They moved methodically across the tundra, letting the equipment equilibrate, and then making flux measurements over a 4 to 6 minute period. These data will be added to other data collected throughout the season. It should be a great dataset and one that will help us as we seek to improve models, especially climate models for the Arctic.


Thursday, November 6, 2014

Taking Down the Tram…

Last May the NGEE Arctic team designed, built, and assembled a 65-meter long tram on the Barrow Environmental Observatory (BEO). The tram consisted of supports, rails, and a motorized cart that carried energy and radiation sensors back and forth across the tundra every 3 hours. It has been operating all summer with few problems. The reliability of the tram is a testament to those who designed the system – Keith Lewin, Bryan Curtis, and Paul Cook. Nice job guys!

Today we set about taking down the rails, supports, and cart for the winter. Keith and Bryan are going to redesign a few things over the winter and add a sensor or two. This will require strengthening the overall infrastructure and reprogramming some of the software. Although this could be done in the field, it makes sense to remove everything now (as per our North Slope Borough (NSB) permit and other safety considerations) and reassemble the new and improved system in the spring before snowmelt.

So, first thing this morning we set about strategically removing clamps that held the rails, and the few nuts and bolts that held the vertical supports. This literally took less than an hour. It was a pretty impressive design with considerable thought given to how the tram could be quickly assembled, and dissembled, in harsh weather. The hardest part was transporting the 16 foot rails and upright supports back to our storage facilities in Barrow. Sleds made this bearable and once everything was strapped in place, John and Bryan could run them back to town in 30 minutes. Two trips were required to get everything safely transported and stored until next spring.

Everyone was glad to have this completed before the end of the day. The winds kicked up to 20 miles per hour this afternoon and the wind chills dropped below -10F. Wind speeds are forecast to increase overnight and into tomorrow so this was a task we were glad to check off our list.

Wednesday, November 5, 2014

Quality Carbon Cycle Measurements Continue…

The NGEE Arctic team is committed to collecting quality datasets that can, in turn, provide knowledge to inform climate models. We are doing this for several disciplines including hydrology, biogeochemistry, and vegetation dynamics. One area where we are especially focused is on the measurement CO2 and CH4 flux from polygonal landscapes on the North Slope of Alaska. These two greenhouse gases, both products of thawing and degrading permafrost, are important inputs to the atmosphere that determine the rate and magnitude of future warming of the planet.

Today our team left the Building 142 staging area a few miles east of Barrow and traveled to our field site using snow machines.  John used a Topcon dGPS to identify locations for our measurements.  He will eventually locate 65 to 70 sites buried beneath 10 to 50 cm of snow, but today John focused on plots along the 65-meter long tram. PVC collars had been installed along the tram earlier in the year and project scientists have been measuring CO2 and CH4 flux routinely throughout the year. Once identified, the collars were gently cleaned and an LGR system was used to measure fluxes per unit ground area over a few minute period. Ori and Naama were able to take all the measurements within a few hours of admittedly limited daylight. It was surprising that despite snow, frozen ground, and ice we were still able to measure positive, albeit low, fluxes for both CO2 and CH4. It will take a few weeks to analyze the data but these final measurements should complete what has been a rewarding and successful 2014 field campaign.

John continues to locate other sites where we will conduct similar measurements tomorrow. We will also be collecting samples of air from stainless steel “gas wells” that had been previously inserted into the active layer.

Tuesday, November 4, 2014

Hit the Ground Running…

John and I woke up early (or at least it was still dark), had breakfast, and then organized everything that had been in storage. Several boxes of equipment had not yet arrived, so we also stopped by Northern Air Cargo (NAC) in hopes of locating them. We quickly found one, but will have to wait until tomorrow to retrieve the other. Bryan, Ori, and Keith arrived at the airport about 10:30am and we soon had everyone checked in, organized, equipped, and dressed for the field, thanks to our logistical provider UMIAQ.

Snow machines made getting to our research site quick and easy. Each year we receive a safety briefing on the proper use and operation of snow machines and today was no exception. However, that took less than 30 minutes and we were on our way just after lunch.  Bryan and Keith examined the tram and all it sensors. We will let it collect another day of data before beginning the disassembly.  John got the dGPS up and running and guided Ori and I to each of our locations where we will measure CO2 and CH4 flux using static chambers beginning tomorrow. Most of these were under snow so it took a few hours of careful excavation to get them ready to measure. Ori and Naama (arriving tonight) should be able to start measurements early tomorrow morning. This set of measurements will be the end of what has been a season-long effort to get estimates of CO2 and CH4 flux before snowmelt, throughout the summer, and now into the winter. This should be a great dataset of model development, validation, and for comparison against larger-scale estimates of carbon cycle processes with the eddy covariance system. More about that tomorrow…

Monday, November 3, 2014

Below Zero in Barrow...Back Again

The days are getting shorter and the temperatures are dropping, but the NGEE Arctic team is once again back in Barrow. John (LBNL) and I arrived on the evening flight and we will be joined by Bryan and Ori (LBNL) and Keith (BNL) tomorrow. We will be here for 10 days to collect end-of-season measurements of CO2 and CH4 flux and a few permafrost cores, and to disassemble the energy tram and its 65 meters of supports and rails. Naama (LBNL) will arrive on Tuesday and will help as we remove the eddy covariance system. Its sensors and data logger will be shipped back to Berkeley for maintenance and calibration.

We have allocated 10 days for our tasks and hopefully that will be sufficient. The days are short with sunrise at 10:30am and sunset at 4:30pm. So, 5.5 hours of sunlight. The temperatures are hovering right at zero with wind chills at -15F. Dressed properly that should not be a problem. While we wait for the others to arrive, John and I will get the snowmachines ready and with luck we can be at our field sites on the Barrow Environmental Observatory (BEO) just after lunch.

Join us this week as we carry out our research.  We should have lots of good pictures and updates on our studies. For now, I snapped a picture just as our plane departed Anchorage earlier this afternoon. Enjoy…

Tuesday, September 2, 2014

Snow Arrives in Barrow...

Although people from the NGEE Arctic project will be coming and going from Barrow throughout the month of September, I leave today on the evening flight for Tennessee. It has been a great trip, first to the Seward Peninsula and then to the North Slope of Alaska. We woke up this morning in Barrow to fresh snow, about an inch. We often comment that “summer” is 90 days in length at this high-latitude location. A quite look back on my notes and albedo records kindly provided by our colleagues at NOAA, suggest that bare ground first appeared this year on June 5 with a snow-free landscape maybe a week later; so just short of a 90 day summer. Hard to believe that biology, at least biology aboveground in the form of vegetation must complete its life cycle in this brief period. Just imagine the challenges of a plant root growing at the permafrost boundary or microbial communities releasing nitrogen through soil organic matter decomposition in this cold, often frozen environment!

As I pack for the trip home, I would like to thank everyone who made this a successful trip. The selection of a series of Phase 2 sites on the Seward Peninsula is a significant milestone for the project, one that will facilitate our modeling objectives into the future, as will the continued science being conducted on the Barrow Environmental Observatory. I would like to thank Cara Mousa who has helped post many of the blogs during this trip. She does a great job of supporting me and the project, and a real lifesaver when I am away from the office.
Also, not too many “Pics of the Week” but here are a few for your enjoyment.  David Graham (ORNL) contributed the photo of the lemming...thanks. And yes, they do play highschool football in Barrow. The season opener pitted the Barrow Whalers against the Homer Mariners. The playing field is easily within sight of the Arctic Ocean.
Be safe, be productive, and enjoy your science! 


Monday, September 1, 2014

NGEE Arctic Scientist Links Plot Scale and Satellite Scale Measurements of Soil Moisture…

Much of what the NGEE Arctic team does is directed at gaining fundamental knowledge of processes that control the water, energy, and carbon cycles in tundra ecosystems. This means that members of the team are in the field and laboratory gathering data and sharing that information with our modeling colleagues. We also have an interest in linking our field studies to larger scale information coming from satellites in what if often referred to as scaling. That is, how do small-scale measurements made in the field relate to larger scale properties and processes estimated from remote sensing platforms?

Go Iwahana, a postdoctoral researcher at the UAF International Arctic Research Center (IARC) is especially interested in this topic and has been working this week to install a network of soil moisture probes across the Barrow Environmental Observatory (BEO). These probes are commercially available and, once connected to a small data logger, can record information on soil temperature and moisture for months at a time. Go plans to use data from this network to evaluate relationships between plot-scale data and that coming from the Soil Moisture Active Passive (SMAP) satellite. The intended goal of SMAP is to provide global measurements of soil moisture and its freeze/thaw state. These measurements will be used to enhance understanding of processes that link the water, energy, and carbon cycles, and to extend the capabilities of weather and climate prediction models. SMAP is a directed mission of NASA (https://smap.jpl.nasa.gov/) and is managed by the Jet Propulsion Laboratory.

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.