Coupling model intercomparison with synthesized experimental data across time and space to constrain carbon dynamics and biogeochemical cycling in permafrost ecosystems

Surface air temperatures in the Arctic are increasing every year with widespread consequences for ecosystems

ecosystem

A natural community of plants, animals, and other living organisms and the physical environment in which they live and interact.

Source: A student's guide to Global Climate Change Source

and Arctic communities. The thawing and degradation of permafrost,

permafrost

Any ground that remains completely frozen—32°F (0°C) or colder—for at least two years straight. These permanently frozen grounds are commonly found in regions with high mountains and near the North and South Poles.

Source: USGS Source

perennially frozen ground, is projected to occur over this century exposing large quantities of frozen carbon to warmer temperatures and microbial degradation. Increased microbial activity is projected to release large amounts of carbon dioxide

carbon dioxide (CO2)

An important heat-trapping gas, also known as a greenhouse gas, that comes from the extraction and burning of fossil fuels (such as coal, oil, and natural gas), from wildfires, and natural processes like volcanic eruptions.

Source: NASA Source

and methane

methane

A hydrocarbon that is a primary component of natural gas. Methane is also a greenhouse gas (GHG), so its presence in the atmosphere affects the earth’s temperature and climate system

Source: EPA Source

to the atmosphere accelerating the rate of global climate change.

climate change

A change in the average conditions — such as temperature and rainfall — in a region over a long period of time.

Source: NASA Climate Kids Source

Earth System Models

earth system model (ESM)

A model that simulates how chemistry, biology, and physical forces work together. These models are similar to, but much more comprehensive than, global climate models.

Source: U.S. Department of Energy Source

need to accurately represent these permafrost carbon dynamics to project the magnitude and timing of permafrost carbon emissions into the future. The complexity of Earth System models requires innovative approaches to evaluate and analyze model results.

Here, we will synthesize

synthesis

The process of combining a number of things into a coherent whole to form a theory or system.

Source: National Library of Medicine Source

data from pan-Arctic experimental warming studies and create new functional benchmarks for models. These benchmarks will be used to evaluate model performance from simulations that align with experimental perturbations (such as soil warming). We will perform model simulations with a suite of Earth System Models at the site-level and with a smaller subset of models at the pan-Arctic scale. Model performance will be evaluated against the synthesized experimental data to assess predictive capability among land models. In addition, results from model simulations will be used to define recommended future changes in model structure and parameterization that will be necessary to represent carbon dynamics for this region. We will also evaluate the temporal and spatial frequency of measured data with Earth System Model performance to guide future observational sampling.

The proposed work will be facilitated by a series of virtual meetings and in-person workshops that are organized in conjunction with the Permafrost Carbon Network. Community engagement will be an integral aspect of the proposed work as we will leverage the science community to actively participate and contribute data and model resources throughout the project. Our proposed activities will bring together modelers with experimentalists who work with Arctic permafrost warming experiments. Collectively, synthesizing experimental data and evaluating model simulations will improve understanding of the permafrost carbon feedback and implications for future climate change.