Quantifying biophysical and biogeochemical influence on northern high latitudes greenhouse gases dynamics
type: CreativeWork
description: In this dissertation, I examined the impacts of biogeophysical-biogeochemical interactions on northern high latitudes (NHLs) greenhouse gases (GHGs) emission in a terrestrial modeling framework. To achieve this objective, I extended and calibrated a land surface model, the Integrated Science Assessment Model (ISAM), to explore how the physical and chemical interactions within the atmosphere-land-soil continuum determined the production, transport and flux of GHGs from site to regional and global scales. I focused on the impacts of three key GHGs that can largely contribute to climate change in terrestrial processes: (1) Carbon Dioxide (CO2), (2) Methane (CH4) and (3) Nitrous Oxide (N2O). In Chapter 1, I provided a brief introduction of the overall objectives and content of this dissertation. The importance of representing (1) vertical heterogeneity of soil column, (2) CH4 transport pathways from soil to the atmosphere and (3) the soil oxygen availability and soil anoxia condition in the land surface model are highlighted. Measured data from multiple sources have been highlighted. In Chapters 2, I developed vertically-resolved soil biogeochemistry (carbon and nitrogen) module and implemented it into a land surface model, ISAM. The model captures the vertical heterogeneity of the Northern High Latitudes permafrost soil organic carbon (SOC). I also implemented Δ14C to estimate SOC turnover time, a critical determinant of SOC stocks, sequestration potential, and the carbon cycle feedback under changing atmospheric CO2 concentration [CO2] and climate. ISAM accounted for the vertical movement of SOC caused by cryoturbation and its linkage to the frost heaving process, oxygen availability, organo-mineral interaction and, depth-dependent environmental modifiers. After evaluating the model processes using the site and regional level heterotrophic respiration, SOC stocks and soil Δ14C profiles, the vertically-resolved soil biogeochemistry version of the model (ISAM-1D) estima…
abstract: In this dissertation, I examined the impacts of biogeophysical-biogeochemical interactions on northern high latitudes (NHLs) greenhouse gases (GHGs) emission in a terrestrial modeling framework. To achieve this objective, I extended and calibrated a land surface model, the Integrated Science Assessment Model (ISAM), to explore how the physical and chemical interactions within the atmosphere-land-soil continuum determined the production, transport and flux of GHGs from site to regional and global scales. I focused on the impacts of three key GHGs that can largely contribute to climate change in terrestrial processes: (1) Carbon Dioxide (CO2), (2) Methane (CH4) and (3) Nitrous Oxide (N2O). In Chapter 1, I provided a brief introduction of the overall objectives and content of this dissertation. The importance of representing (1) vertical heterogeneity of soil column, (2) CH4 transport pathways from soil to the atmosphere and (3) the soil oxygen availability and soil anoxia condition in the land surface model are highlighted. Measured data from multiple sources have been highlighted. In Chapters 2, I developed vertically-resolved soil biogeochemistry (carbon and nitrogen) module and implemented it into a land surface model, ISAM. The model captures the vertical heterogeneity of the Northern High Latitudes permafrost soil organic carbon (SOC). I also implemented Δ14C to estimate SOC turnover time, a critical determinant of SOC stocks, sequestration potential, and the carbon cycle feedback under changing atmospheric CO2 concentration [CO2] and climate. ISAM accounted for the vertical movement of SOC caused by cryoturbation and its linkage to the frost heaving process, oxygen availability, organo-mineral interaction and, depth-dependent environmental modifiers. After evaluating the model processes using the site and regional level heterotrophic respiration, SOC stocks and soil Δ14C profiles, the vertically-resolved soil biogeochemistry version of the model (ISAM-1D) estima…
author: Shu, Shijie
language: en
keywords: Northern High-Latitudes, Permafrost, Soil Organic Carbon Dynamics, Soil Methane, Wetland Methane Emissions, Non-wetland Methane Emissions, Methane Dynamic Model, Nitrous Oxide
date published: 2022-01-12T22:56:08Z
date modified: 2026-07-22T22:24:53Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/113316