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

Table 1 Model parameters for the calculation of GHG emissions due to the dynamic and thermodynamic permafrost degradations

Model parameter	Variable	Standard value	Uncertainty range	References
V_dstrb [cm/yr]	Subsidence velocity of burnt area in Yedoma layer	2.4	± 2.1	a
r_ice	Ice contents in Yedoma layer	0.64	± 0.15	b
d_soc [m]	Depth of average soil organic layer	3.0	± 1.5	c
π	Fraction for the flux of soil organic carbon, fast pool slow pool	0.025 0.45	0.01–0.04 0.30–0.60	d, e, f, g, h, i
τ [year]	Time scale for slow decomposition at 5 °C	25	10-40	d, e, f, h
∆r_{wtlnd, max} [%]	Maximum increase of wetland fraction	20	10-30	d
Q10	Temperature sensitivity parameter, aerobic anaerobic	2.5 3.0	1.5–3.5 4.0–6.0	d, i, j
r_gas	GHG production ratio, CH₄:CO₂ in aerobic CH₄:CO₂ in anaerobic Fast pool Slow pool	1:50 1:1 1:7	± 50% ± 20% ± 50%	k, m, n, p
oxd	CH₄ oxidation rate, anaerobic	0.20	0.15–0.40	h

The standard values and uncertainty ranges of the parameters are shown. References for the standard values and uncertainty ranges are as follows. a: Iwahana et al. (2016), b: Strauss et al. (2017), c: Saito et al. (2020), d: Schneider von Deimling et al. (2015), e: Sitch et al. (2003), f: Dutta et al. (2006), g: Koven et al. (2011), h: Burke et al. (2012), i: Schadel et al. (2014), j: Walter and Heimann (2000), k: Lee et al. (2012), m: Schuur et al. (2008), n: Segers (1998), p: Walter Anthony et al. (2014)