Changes between Version 57 and Version 58 of Branches/Driver_Improvements

Timestamp:

2016-06-18T16:13:29+02:00 (8 years ago)

Author:

jpolcher

Comment:

--

Branches/Driver_Improvements

@@ -266 +266 @@
 - Note that the map of PGF is probably shifted by half a grid spacing in longitude and latitude.
 
-
+= Discussions between Nicolas Vuichard and Jan Polcher (16/616) =
+
+During a discussion we came to the conclusion that there must be a configuration of dim2driver and orchideedriver which yield the same results for the CRUNCEP forcing. We believed this to be the case as CRUNCEP was designed for dim2driver. It is the only forcing which contains different time axes for scalar and fluxes and the attributes needed for orchideedriver.
+
+Tests were performed and some additions made to orchideedriver to try and achieve this. The following steps were needed and are now committed on the SVN server :
+
+1) Dawn and dusk issues in orchideedriver : The spikes in SWdown in the new driver are an indication that the solar angle becomes zero too quickly. The formulation used in readim2.f90 for generating the diurnal cycle could not be understood. So the solution was to implement a dawn_angle in orchideedriver. This is the solar angle from which the diffuse radiation is dominant and light still reaches the ground although the sun is setting. For the angles between zero and this dawn_angle the solar angle is maintained at  dawn_angle.
+
+2) maintaining LWdown : A nearest neighbour interpolation was implemented in orchideedriver. It is activated with the LWDOWN_cons=y. In dim2driver this same result is obtained with INTER_LIN = y
+and NETRAD_CONS = y.
+
+3) The vegetation is not started in the same way in both drivers. It was decided to launch both simulations with the same restart file.
+This surprising behaviour of the initialisation of the model is probably a bug in slowproc.f90.
+
+The results are presented below.
+
+
+