The Carbon Cycle Flashcards
How do modify the forcings-and-feedbacks formula for climate response when changing the CO2 concentration?
This acts as an additional (non-radiative) feedback, hence we include an additional term for Q’.
What is the formula for a forcing with the additional CO2 feedback term?
Q’ = - alpha T’_s - lambda T’_s + c dT’_s/dt.
Where alpha is a new constant.
What does a positive value for a alpha indicate?
The ocean/land is emitting net CO2 and hance the equilibrium change is larger than before. If (lambda + alpha) >= 0, we have runaway climate change and temperature increases infinitely.
What does a negative value for alpha indicate?
The carbon cycle feedback acts to reduce CO2 concentration and the ocean remains to be a sink for CO2.
What is the GPP (variable and physical meaning)
Pi - The gross primary productivity is the uptake of carbon due to photosynthesis.
What is R_E?
The respiration rate.
What is the formula for the rate of change of total carbon stored in the vegetation and soil.
dC_T/dt = Pi - R_E
What is the main determiner for GPP?
The atmospheric CO2 concentration, C_a
How do we mathematically define GPP?
Pi = Pi_max (C_a / (C_a + C_0.5))
Where C_0.5 is the constant value for CO2 concentratio where half Pi_max is achieved.
What does the value C_0.5 depend on?
The particular species of the plants present.
What does the rate of R_E depend on?
It is a strong function of temperature and carbon availability in the system.
What condition must we have on the rate of change of of carbon stored in vegetation/soil for the land to be a source of carbon?
dC_T / dC_a < 0, hence C_a > C_0.5 (1 - mu) / mu
Where mu = -0.535/lambda ln(q_10)
