Abstract

There is mounting evidence to suggest that changing patterns of precipitation and land surface temperature are affecting the physical structure and chemistry of soils across the continent via complex interactions between microbial communities and root growth. The macroporosity of soil, specifically, appears to be responding to trends in precipitation magnitude at sub-decadal timescales. Such changes to soil texture may influence several critical hydrologic and biogeochemical processes, including the distribution and dynamics of soil moisture. We are leveraging insights gleaned from pedon- and watershed scale modelling efforts to parameterize a set of climate-responsive pedotransfer functions into the Community Land Model (CLM) 5.0. Land models such as CLM provide an opportunity to gain insight into continental-scale interactions among various land-atmosphere fluxes over large spatial and temporal scales, but have historically treated soils as static. Here, we present the initial results from a set of conservative experimental model runs designed to understand how the maximum projected positive and negatives changes to soil macroporosity may affect the magnitude and distribution of infiltration, soil moisture, percolation, groundwater recharge and runoff generation at a continental scale. The inclusion of such climate-responsive pedotransfer functions in land models has the potential to help illuminate previously under-characterized interactions among various stocks and fluxes relevant to land-atmosphere interactions, and project how such interactions might influence hydrologic and biogeochemical outcomes under future climate scenarios.

Citation

Nash, Caroline, Alejandro N Flores, Pamela L Sullivan, Daniel Hirmas, Sharon A Billings, Li Li, Hang Wen (2019): Modelling the effects of climate-responsive soil parameters on continental-scale hydrologic stores and fluxes in the Community Land Model (CLM) 50. American Geophysical Union Fall Meeting, San Francisco, CA, December 9-13, 2019.

This Paper/Book acknowledges NSF CZO grant support.