Progress & Accomplishments

Susan Hubbard Selected as the 2016 Hal Mooney Award Recipient

The Hal Mooney Award recognizes an individual for extraordinary near-surface geophysical scientific achievements and community service.

Methane Oxidation in Degraded Polygonal Tundra

Significant methane oxidation activity was observed in incubations of flat-centered polygon transitional soil and permafrost layers, which also exhibited high levels of methane production activity under anoxic conditions.

Graham.png

Figure 1. Conceptual model of aerobic and anaerobic soil organic carbon decomposition pathways, Fe(II), CO2 and CH4 concentration profiles in a flat-centered polygon. The spatial correlation between methanogenesis and methane oxidation potential indicates

Representing Leaf and Root Traits Improves Carbon and Nitrogen Cycling Predictions

Explicitly representing plant physiological root traits and improving the nutrient competition algorithm with the Equilibrium Chemistry Approximation removes known biases in CLM and ALM.

Riley.png

Figure 3. Gross Primary Production (GPP) in the default model (blue) had an unrealistic diurnal cycle that is resolved with improved representation (red) of nutrient competition and root and leaf physiological traits

Coincident Above- and Below-Ground Autonomous Monitoring Strategy: Development and Use to Monitor Arctic Ecosystem Freeze-Thaw Dynamics

Soil moisture and thaw thickness strongly influence vegetation, and can serve as a proxy for vegetation greenness (and vice versa) during the growing season.

Dafflon.png

Figure 1. a) Correlation and normalized mean absolute error between bulk electrical conductivity (in top 20 cm soil) and green chromatic coordinate from July 1 (day 0) to August 11 (day 40) 2014 (using 72 locations along a 35 m long transect crossing var

Strait Science Series - The Seward Peninsula’s Future: Wetter or Drier?

NGEE Arctic participates in University of Alaska Fairbanks Northwest Campus’ platform to discuss ongoing hydrology research efforts with the community.

Arendt.jpg

Figure 1. Members of the NGEE Arctic hydrogeochemistry team, Carli Arendt and Lauren Charsley-Groffman, setting up a sampling location at the headwaters of the primary Teller field site drainage.

Demonstration of CLM-PFLOTRAN Coupling Lays a Foundation for Biogeochemistry Simulation Across Scales

An implicit time-stepping model for decomposition, nitrification, denitrification, and plant nutrient uptake was implemented in the Community Land Model (CLM), the land ecosystem component of a coupled Earth System Model.

fig 3.png

The graphic illustrates how the original CLM representation of nutrient limitation, based on relative demand of plants and microbes for available resource (a), can be reproduced through the appropriate parameterization of a more traditional Monod equation

A Generic Law-of-the-Minimum Flux Limiter for Simulating Substrate Limitation in Biogeochemical Models

Complex biogeochemical networks that include many biotic and abiotic processes can be limited by different substrates under different conditions during their temporal evolution.

Fig 4.png

Predicted decomposition dynamics for a Century-like biogeochemical network that includes carbon, nitrogen, and phosphorus. “CLM-1” and “CLM-2” are ad hoc approaches based on CLM4.5BGC; “New” is our flux-limiter approach; “mBBKS” is the global flux-limiter

Uncovering Labile Soil Organic Matter Degradation Pathways in Polygonal Tundra

Permafrost thaw and climate warming accelerates frozen soil organic carbon (SOC) degradation and emission of greenhouse gases, but what specific degradation pathways for labile SOC occur prior to CH4 and CO2 production are not well understood.

Conceptual model of anaerobic labile soil organic carbon (SOC) degradation pathways in the active layer of polygonal tundra upon warming.

New Website for NGEE Arctic

The NGEE Arctic website, to be released later in April, will have a new look and feel moving from an unsupported Drupal 6 into Drupal 7.

web.png

NGEE Arctic Data Management Team Working with NGEE Tropics

The ORNL NGEE Arctic Data Management Team (DMT) is lending expertise and tools deployed for the NGEE Arctic data effort to the NGEE Tropics project. The DMT has deployed a multi-faceted system for NGEE Arctic comprised of the On-line Metadata Editor (OME)