https://agu.confex.com/agu/fm22/meetingapp.cgi/Paper/1055693

Dutch, V.R., Rutter, N., Wake, L.M. et al. (2022) Stimulating soil respiration under seasonal snow cover at an Arctic tundra site. American Geophysical Meeting, Chicago, United States of America, (December 12-16). https://agu.confex.com/agu/fm22/meetingapp.cgi/Paper/1055693

Quantification of winter season carbon fluxes across the Arctic region provided by either earth system models or empirical estimates varies by a factor of three and a half (377 – 1301 Tg Carbon; (Natali et al., 2019)). In this study, we look at the representation of wintertime carbon fluxes at Trail Valley Creek, NWT, Canada using point simulations of the Community Land Model (CLM5). We test the sensitivity to changes to modelled relationships between soil temperature, moisture, and decomposition, as well as the impact of a change in snow thermal conductivity scheme to correct for a previously noted soil temperature bias. We find that the default value of ?min (the soil moisture threshold on decomposition) is too high and prevents soil respiration from being simulated for the vast majority of the winter. The default value of Q10 does not correspond with observed values in similar environments, contributing to poor simulation of soil respiration. Parameter changes tend towards equifinality, with Q10 and ?min having opposing effects on the magnitude of simulated soil respiration. Observational limitations and uncertainties mean suggesting ideal parameter values is unwise, but we suggest a more suitable parameter space for Arctic simulations than the values used by default in CLM

https://agu.confex.com/agu/fm22/meetingapp.cgi/Paper/1055693