Project Funding: 2016 - 2020

NRA: 2016 NASA: Terrestrial Ecology   

Funded by NASA

Abstract:
I. Introduction and objectives Carbon release from permafrost regions upon degradation is one of the greatest uncertainties for projections of future climate. Lack of knowledge about rate of permafrost degradation, its spatial variation, and carbon storage in the permafrost represents a major source of uncertainty for the future climate projection. Permafrost thaw and degradation promotes the mobilization of organic matter, water and greenhouse gases (GHG). It is of great scientific interest and social concern to know where and to what extent permafrost degradation may occur, especially in ice-rich permafrost, as consequential subsidence by thaw (thermokarst) will cause large changes in surface ecology, landscape evolution, and hydrological processes, and will also affect local life and subsistence. Objectives in these case studies are to: 1. Measure the spatial variation of thermokarst subsidence, using InSAR and LiDAR differencing techniques; 2. Improve uncertainty in the thermokarst quantification by remote sensing; 3. Estimate GHG and organic matter contents in permafrost, including in the ground ice body; and 4. Evaluate the rates of potential release of carbon upon thermokarst development II.Methods We propose conducting an investigation to determine subsided volume due to thermokarst, combining remote sensing techniques and field surveys. We will employ a DInSAR (Differential Interferometry Synthetic Aperture Radar) technique, using data from the past and new NASA airborne campaigns and L-band SAR (ALOS (2) / PALSAR (2)) to measure the rate of thermokarst subsidence and its spatial variation in wide areas of permafrost regions. ABoVE airborne operations with LIDAR and RADAR over targeted areas are expected to provide ranges of seasonal surface movement and active layer thickness, which are critical information to reduce uncertainty for quantification of inter-annual subsidence due to thermokarst development. Optical space-borne sensors capable of capturing ground objects in sub-meter spatial resolution will be used to detect thermokarst development through land surface texture changes. In-situ, high-accuracy GPS mapping, UAV topographical survey, and geocryological analysis support the thermokarst measurements by airborne and satellite remote sensing. We will further sample permafrost sediments and ground ice in the selected target areas to analyze the concentration of greenhouse gases and the amount of organic matter. Drill-core and surface soil samples will be kept frozen for laboratory measurement of greenhouse gas concentration and volume. III. Significance of the proposed study Our goal is to greatly increase our knowledge about the conditions and disturbances that lead to thermokarst and permafrost thaw in Arctic ice-rich permafrost regions. Thawing of permafrost whether by human disturbance, fire, or climate change will have direct and indirect consequences for local societies by way of effects on infrastructure, changes in water availability and quality, nutrient cycles and habitat. In addition, the potentially very large release of GHG from permafrost thaw could have catastrophic consequences for the global climate. We therefore believe this proposed study will not only increase our scientific understanding of permafrost dynamics in the Arctic, but will also generate further understanding about Arctic ecosystem carbon exchange dynamics that are of crucial importance for the well-being of all societies on earth. This project relates particularly to the future NASA L-band SAR program NISAR, and our proposed method for quantification of thermokarst in permafrost regions represents a promising application of NISAR, while also serving as an important carbon-monitoring task for future projects.

Publications:

Bristol, E. M., Connolly, C. T., Lorenson, T. D., Richmond, B. M., Ilgen, A. G., Choens, R. C., Bull, D. L., Kanevskiy, M., Iwahana, G., Jones, B. M., McClelland, J. W. 2021. Geochemistry of Coastal Permafrost and Erosion-Driven Organic Matter Fluxes to the Beaufort Sea Near Drew Point, Alaska. Frontiers in Earth Science. 8. DOI: 10.3389/feart.2020.598933

Glass, T. W., Breed, G. A., Iwahana, G., Kynoch, M. C., Robards, M. D., Williams, C. T., Kielland, K. 2021. Permafrost ice caves: an unrecognized microhabitat for Arctic wildlife. Ecology. 102(5). DOI: 10.1002/ecy.3276

Iwahana, G., Busey, R., Saito, K. 2020. Seasonal and Interannual Ground-Surface Displacement in Intact and Disturbed Tundra along the Dalton Highway on the North Slope, Alaska. Land. 10(1), 22. DOI: 10.3390/land10010022

Iwahana, G., Cooper, Z. S., Carpenter, S. D., Deming, J. W., Eicken, H. 2021. Intra-ice and intra-sediment cryopeg brine occurrence in permafrost near Utqiagvik (Barrow). Permafrost and Periglacial Processes. 32(3), 427-446. DOI: 10.1002/ppp.2101

Mekonnen, Z. A., Riley, W. J., Berner, L. T., Bouskill, N. J., Torn, M. S., Iwahana, G., Breen, A. L., Myers-Smith, I. H., Criado, M. G., Liu, Y., Euskirchen, E. S., Goetz, S. J., Mack, M. C., Grant, R. F. 2021. Arctic tundra shrubification: a review of mechanisms and impacts on ecosystem carbon balance. Environmental Research Letters. 16(5), 053001. DOI: 10.1088/1748-9326/abf28b

Muskett, R. R. 2018. To Measure the Changing Relief of Arctic Rivers: A Synthetic Aperture RADAR Experiment in Alaska. Journal of Geoscience and Environment Protection. 06(09), 207-222. DOI: 10.4236/gep.2018.69016

Muskett, R. R. 2021. GRACE, the Chandler Wobble and Interpretations of Terrestrial Water Transient Storage. International Journal of Geosciences. 12(02), 102-120. DOI: 10.4236/ijg.2021.122007

Yang, J., Ahn, J., Iwahana, G., Han, S., Kim, K., Fedorov, A. Brief Communication: The reliability of gas extraction techniques for analysing CH<sub>4</sub> and N<sub>2</sub>O compositions in gas trapped in permafrost ice-wedges DOI: 10.5194/tc-2019-231

Yokohata, T., Saito, K., Ito, A., Ohno, H., Tanaka, K., Hajima, T., Iwahana, G. 2020. Future projection of greenhouse gas emissions due to permafrost degradation using a simple numerical scheme with a global land surface model. Progress in Earth and Planetary Science. 7(1). DOI: 10.1186/s40645-020-00366-8

Yokohata, T., Saito, K., Takata, K., Nitta, T., Satoh, Y., Hajima, T., Sueyoshi, T., Iwahana, G. 2020. Model improvement and future projection of permafrost processes in a global land surface model. Progress in Earth and Planetary Science. 7(1). DOI: 10.1186/s40645-020-00380-w

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

• NASA Terrestrial Ecology (TE) Project Profile
• NASA Arctic-Boreal Vulnerability Experiment (ABoVE) Project Profile