Changes between Version 145 and Version 146 of Documentation/TrunkFunctionality4

Timestamp:

2023-11-22T20:36:50+01:00 (7 months ago)

Author:

luyssaert

Comment:

--

Documentation/TrunkFunctionality4

@@ -190 +190 @@
 The above declaration implies that 9/15th of the trees will always be in the smallest diameter class, 5/15th will be in the medium class and 1 tree out of 15 will be in the largest diameter class. These ratios are kept throughout the simulations and the boundaries of the diameter classes are adjusted to respect this constraint. Consequently, an even-aged stand will be simulated with three diameter classes where the diameter of the first class may be, for example, 20.3 cm, the diameter of the second class 20.4 cm and the diameter of the third class 20.5 cm. The same code and set-up allows to simulate, in the same simulation, an uneven-aged stand for the same PFT but in a different pixel with, for example, the smallest diameter 7 cm, the medium diameter 25 cm and the largest diameter 45 cm.
 
+=== Dynamic tree height ===
+Prior to r8316 the parameter describing the tree height for a tree with a diameter of 1 m was PFT-specific. This parameter is used in the calculation of tree height from tree diameter. From r8316 the option HACK_DYNAMIC_HEIGHT has been added. The user can now chose between a fixed PFT-dependent value for PIPE_TUNE2 or to calculate a pixel-dependent value for PIPE_TUNE2. The pixel-dependent value is calculated as a function of precipitation. The underlying approach and parameters are documented in src_parameters/dynamic_parameters.f90. The functionality can be activated by setting HACK_DYNAMIC_HEIGHT=y. Note that this functionality has been coded as a hack because we need to decide which approach we want to use. Only one of the options should be maintained. When running the code with or without HACK_DYNAMIC_HEIGHT the temporal dynamics of tree height vary quite a lot. As a consequence PIPE_TUNE3 is very different. constantes_mtc now defines a pipe_tune3a and pipe_tune3b for the two options. Parameters for the height-precipitation relationship has been fitted on GEDI by making use of CRUJRA. Although these parameters should not be changed/tuned unless the fitting is redone, these parameters (ALPHA_HEIGHT_PRECIP and BETA_HEIGHT_PRECIP) have been externalized.
+
+
 === Experiments ===
 Describes r8017. The model comes with the following well-tested offline experiments found in folder config/ORCHIDEE_OL. Well-tested means that these set up of experiment have been tested on different servers and some of the experiments are part of the trusting: