The Arctic Environmental Problems - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 583

dC 8 = dt ¼ l X 1 Y ð Þ= Y ;

ʼ

where c growth rate of respective microbial population with biomass X,

Y is biomass yield per unit of substrate consumed. Microbial biomass X is formed
with the following law:

is speci

dX = dt ¼ l X ;

S þ K ð Þ , S is catabolic substrate concentration, R is the
function of physiological state, K S is saturation constant, numerically equal to that
substrate concentration at which microbial speci

l ¼ l max SR =

where

c growth rate attains the half of

maximal value ( ʼ = 0.5 ʼ max ).
Natural wetlands and rice paddies deliver to the atmosphere more than 30 % of
global CH 4 emission. Flux C 3 can be parameterized by the following equation:
C 3 ¼ H r f 1 T ð f 2 ðÞ f 3 p ð f 4 r p ;

where H r is heterotrophic respiration, T s is soil temperature, h is water table

position, r p is redox potential, functions fi i (i=1 4) parameterized the CH 4 emission

rates. Fluxes C 1 and C 2 that characterize major atmospheric CH 4 sinks are mainly
parameterized by its reaction with hydroxyl (OH) radical. These

-

uxes depend on
the OH levels and reaction rate. Under this, it is known that increase in methane
leads to positive feedback (Xu et al. 2007; Krapivin and Varotsos 2008).
The scheme of Fig. 6.27 is realized by global carbon cycle model (GCCM)
blocks of which are characterized in Fig. 6.29 and Table 6.25 . Many of the GCCM
blocks have form of coupled set of time-dependent advection, diffusion, and
reaction equations. Set of theoretical and empirical models for the carbon

fl

fl fluxes of

Fig. 6.27 are realized by speci c blocks, represented in Fig. 1.30 . (Kondratyev et al.

2003b; Degermendzhi et al. 2009; Williams and Follows 2011).

Fig. 6.29 Structure of the
GCCM. Notation is given in
Table 6.25