Project Funding: 2015 - 2019

NRA: 2014 NASA: Terrestrial Ecology   

Funded by NASA

Abstract:
The proposed research combines geospatial data products derived from airborne and spaceborne remote sensing (RS) data with targeted field observations and modeling in order to quantify ecosystem responses to Arctic and boreal environmental change. Specifically, we will quantify methane (CH4) ebullition (bubbling) emissions associated with 60 years of permafrost thaw in thousands of Alaskan and NW Canadian lakes by direct observation with RS systems. Our objective is to develop regional, multi-scale and multi-temporal maps of western North America's boreal and Arctic lake area change and associated CH4 ebullition emissions using Synthetic Aperture Radar (SAR), high resolution optical RS, field work, and numerical and GIS modeling in order to improve our understanding of the vulnerability and resilience of lake ecosystems to permafrost thaw with respect to the release of 14C depleted (old) CH4-carbon from decomposition of permafrost soil organic carbon (SOC). We will expand upon our predecessor NASA-funded projects #NNX08AJ37G and #NNX11AH20G which developed statisticallysignificant models using SAR, optical and infrared RS data to detect and quantify CH4 ebullition emissions at intra-, whole- and regional-lake scales. We also established a relationship between observed CH4ebullition and average annual SOC inputs to a handful of Alaskan lakes via thermokarst-margin expansion during recent decades using field data, radiocarbon dating and modeling. Our next goals are to: (i) Quantify CH4 ebullition in thousands of thermokarst-affected lakes in Alaska and NW Canada, spanning a range of climate, Arctic/boreal, permafrost SOC (e.g. yedoma/non-yedoma) and lake-change regimes using established and cross validated relationships between SAR and optical RS signals and field-observed CH4 ebullition; (ii) Formulate a mathematical relationship between SOC inputs to lakes during the past ~60 years and field- and RS observed CH4 emissions; and (iii) As a stretch goal, invert the relationship in (ii) to produce experimental maps of permafrost SOC stocks, which are vulnerable to CH4 production upon thaw. This multi-scale project will include: (1) Collection of new and synthesis of existing field data on CH4 ebullition, thaw-bulbs and SOC; (2) analysis of existing data from aerial surveys, SAR and optical RS of CH4 in lake ice; (3) orthorectification of historic aerial photos for comparison to high-resolution satellite imagery to produce fine-scale regional maps of lake area change, (4) model estimations of permafrost SOC quantities eroded into lakes; (5) radiocarbon dating CH4 and SOC, (6) GIS modeling to produce multi-temporal regional maps of historic lake area change, associated CH4 emissions, and permafrost SOC stocks; (7) outreach to stakeholders at Alaska village and rural community field sites; and (8) participation in ABoVE Science Team (ST) meetings and workshops. Anticipated results include process-level data to aid understanding the effects of lake area change on regional lake CH4 ebullition emissions across diverse permafrost SOC regimes. We will also produce experimental high-resolution regional maps of estimated permafrost SOC stocks that are vulnerable to CH4 production and ebullition emission upon thaw. Other ancillary data products will include time-series of geocoded (ortho-type) remote sensing products from SAR and optical sensors as well as time-series of lake boundary data for extended areas of the ABoVE Study Domain ('Historical Hydro'). Data and maps will be staged to the ABoVE Science Cloud (ASC) for use by other ABoVE ST members, the CCEO and policy-makers who communicate with stakeholders, and partnering programs, such as the DOE's NGEE. Project goals will meet shared objectives of NASA's Terrestrial Ecology Research and the North American Carbon Program (NACP) for understanding and predicting changes in North American C pools (e.g. permafrost stored C converted to CH4 in thermokarst lakes).

Publications:

Engram, M., Arp, C. D., Jones, B. M., Ajadi, O. A., Meyer, F. J. 2018. Analyzing floating and bedfast lake ice regimes across Arctic Alaska using 25 years of space-borne SAR imagery. Remote Sensing of Environment. 209, 660-676. DOI: 10.1016/j.rse.2018.02.022

Engram, M., Walter Anthony, K. M., Sachs, T., Kohnert, K., Serafimovich, A., Grosse, G., Meyer, F. J. 2020. Remote sensing northern lake methane ebullition. Nature Climate Change. 10(6), 511-517. DOI: 10.1038/s41558-020-0762-8

Walter Anthony, K., Schneider von Deimling, T., Nitze, I., Frolking, S., Emond, A., Daanen, R., Anthony, P., Lindgren, P., Jones, B., Grosse, G. 2018. 21st-century modeled permafrost carbon emissions accelerated by abrupt thaw beneath lakes. Nature Communications. 9(1). DOI: 10.1038/s41467-018-05738-9

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

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