Changes between Version 2 and Version 3 of Documentation/UserGuide/SpinUpCarbon

Timestamp:

2019-01-14T23:03:44+01:00 (5 years ago)

Author:

peylin

Comment:

--

Documentation/UserGuide/SpinUpCarbon

@@ -3 +3 @@
 == Principle ==
 The carbon stocks and fluxes take a relatively long time to be in equilibrium when starting from zero.
- - Above ground C stocks/fluxes: The spin up is much longer 
- - Below ground C stocks/fluxes
+ - Vegetation C stocks/fluxes: The spin up need to bring the vegetation above and below ground carbon stocks at equilibrium; this is relatively short for the LAI: few decades or even just one decade. For the other C pools it is linked to the turnover of the Sap/Heart wood C pools: usually 100 to 200 is sufficient   
+ - Soil C stocks/fluxes: These pools takes much longer to be in equilibrium as the slow C pools has a turnover of several hundred of years => Usually we need several thousand years to reach the equilibrium; Using the analytical spin up reduce this step as we then only need to have the input of C to the soil in equilibrium.
 
 
@@ -10 +10 @@
 A standard protocol is provided in the TRENDY model intercomparison project.
 The protocol comprises:
- - a long simulation equivalent to several thousands of years should be done, recycling the meteorological forcing (usually recycling the first 10 years of forcing) and choosing the atmospheric CO2 concentration of "preindustrial conditions"; This brings the above and below ground C pools into equilibrium. It should be done either with:
-  - the analytical spin up activated: in this case a relatively shorter simulation should be done in order to brind the above ground C pools (tree biomass) into equilibrium => this provides and "equilibrium" for the input of C to the soil; the analytical spin up then allows to bring the soil carbon pools in one matrix inversion given that the soil carbon dynamic follows first order kinetic equations. 
-  - or the force soil routine or the ==> This first step lead to an equilibrium of all reservoirs with the chosen climate and atmospheric CO2 concentration
- - a transient simulation 
- - 
+ - '''1) A long spin up simulation''' equivalent to several thousands of years should be done, recycling the meteorological forcing (usually recycling the first 10 years of forcing) and choosing the atmospheric CO2 concentration of "preindustrial conditions"; This brings the above and below ground C pools into equilibrium. It should be done either with:
+  - The analytical spin up: in this case a relatively shorter simulation should be done (around 150 yr) in order to brind the above ground C pools and fluxes into equilibrium => this provides and "equilibrium" for the input of C to the soil; the analytical spin up then allows to bring the soil carbon pools in one matrix inversion given that the soil carbon dynamic follows first order kinetic equations. 
+  - Or Force soil routine: 
+  - Or simple model simulation for 2-3 thousand years (using recycled meteorological forcing) 
+ ==> This first step lead to an equilibrium of all reservoirs with the chosen climate and atmospheric CO2 concentration
+ - ''' 2) A transient simulation''' is usually done varying the meteorological forcing and the atmospheric CO2 from pre-industrial time to current day (or just to the start of the period that is investigated) in order to have the effect of rising CO2 and changing climate on the gross and net carbon fluxes and the C pools.
+ - ''' 3) An historical run''' is then done which is just the follow up of the transient run 
 
-== Typical time constant ==
-
-