Project Funding: 2014 - 2017

NRA: 2012 NASA: Interdisciplinary Research in Earth Science   

Funded by NASA

Abstract:
We will investigate the response of permafrost to the unprecedented loss of Arctic sea ice since 2005, coupling NASA’s unique satellite and airborne sensor data with state-of-the-art models to (1) Quantify the 2005-2015 changes in permafrost, carbon fluxes, and energy balance in the Arctic as it transitions into a seasonally sea ice-free state; (2) Characterize the fundamental processes driving these changes; (3) Identify testable hypotheses and new permafrost remote sensing opportunities for upcoming NASA missions and field campaigns (eg SMAP, OCO-2, ABoVE). Our technical approach combines remote sensing data with the CLM4.5, ECCO2-Darwin and GEOS-Chem models to characterize the fundamental processes causing rapid changes and threshold behavior in Arctic permafrost, carbon cycle, and surface energy balance. Permafrost Vulnerability: What thresholds indicate when and where large-scale permafrost thaw will occur? We will employ the process-rich Community Land Model (CLM) driven by actual meteorology and sea ice trends for 2005-2015 to identify emergent properties of the terrestrial Arctic. We will investigate the impacts of a seasonally sea ice-free Arctic upon the state of permafrost, snow cover, talik formation, and biogeochemical cycling via a series of targeted sensitivity experiments that isolate specific forcing mechanisms and processes. Carbon Cycle: Have recent changes in sea ice extent accelerated the rate of permafrost carbon release to the atmosphere or altered its CH4/CO2 ratio? We will use CLM4.5 and ECCO2-Darwin to model spatially and temporally resolved surface-atmosphere carbon fluxes during 2005-2015 for the Arctic land and oceans, respectively. We will transport these fluxes using GEOS-Chem to create 4D atmospheric fields. Modeled fields will be compared to atmospheric CO2 and CH4 measurements from satellites (SCIAMACHY, GOSAT), air (ARCTAS, CARVE, HIPPO, NOAA) and ground (CARVE, NOAA, FLUXNET). Energy Balance: What are the oceanic and atmospheric responses to diminishing Arctic sea ice cover and how do these responses impact terrestrial permafrost? We will create a 2005-2015 Arctic surface energy data record from A-Train satellite observations supplemented with meteorological reanalysis data. Our main deliverable will be a quantified energy balance budget for both Arctic land and ocean surfaces. We will deliver a 2005-2015 retrospective analysis that quantifies changes in Arctic permafrost, carbon fluxes, and surface energy balance due to the extreme changes in sea ice extent during this period. Our work addresses two interconnected IDS themes: ROLE OF PERMAFROST IN A CHANGING CLIMATE and IMPACTS OF CHANGING POLAR ICE COVER. We move beyond the study of the Arctic permafrost, sea ice, ocean and atmosphere and as individual components by synthesizing observational data and modeling within a coupled systems approach to elucidate the fundamental processes causing accelerated change in the Arctic. Our results will have a significant and immediate impact on the understanding of thresholds and nonlinear climate sensitivities of permafrost vulnerability. They will strengthen the scientific basis for interpreting observations from OCO-2 and SMAP, key missions in NASA’s Climate Monitoring Architecture. Our innovative, interdisciplinary investigation and data will benefit the Water and Energy Cycle and the Carbon Cycle and Ecosystems focus areas and the Cryosphere Science, Earth System Modeling, Physical Oceanography and Atmospheric Radiation programs of NASA’s Earth Science Directorate. We benefit from and leverage advances made by NASA’s Carbon Monitoring System Flux Pilot in GEOS-Chem (new CO2 and CH4 capabilities) and ECCO2-Darwin (biogeochemistry). More broadly, our investigation will reduce uncertainties for critical components of the Arctic, addressing high priority research objectives of the Arctic Climate Impact Assessment, the National Climate Assessment, and A US Carbon Cycle Science Plan.

Publications:

Parazoo, N. C., Koven, C. D., Lawrence, D. M., Romanovsky, V., Miller, C. E. 2018. Detecting the permafrost carbon feedback: talik formation and increased cold-season respiration as precursors to sink-to-source transitions. The Cryosphere. 12(1), 123-144. DOI: 10.5194/tc-12-123-2018

Yi Y, Kimball J S, Chen R H, Moghaddam M, Miller C E. 2019 Sensitivity of active-layer freezing process to snow cover in Arctic Alaska. The Cryosphere. 13(1), 197-218. DOI: 10.5194/tc-13-197-2019

2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• Observations and Simulations of the Alaskan CO2 Cycle   --   (Nick Parazoo, Charles Miller, John R. Worden, Colm Sweeney, Anna Karion, Christian Frankenberg, Kevin W Bowman, Charlie D Koven, Eugenie Euskirchen, Sander Veraverbeke)   [abstract]

More details may be found in the following project profile(s):

• North American Carbon Program (NACP) Project Profile
• NASA Arctic-Boreal Vulnerability Experiment (ABoVE) Project Profile