Changes between Version 79 and Version 80 of Documentation/Forcings


Ignore:
Timestamp:
2018-02-22T11:36:25+01:00 (6 years ago)
Author:
aducharne
Comment:

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  • Documentation/Forcings

    v79 v80  
    5151 
    5252(b) '''Two versions of the driver are available''' to do do both the reading and the inter/extrapolation of the forcing datasets. They differ in the way they interpret the time at which the diffrent variables are read in the forcing dataset (further called the timestamp, while the interval refers to the period between two succesive timestamps): 
    53 * '''the old driver (src_driver/dim2driver)''', which assumes that scalar variables (Tair,Qair,Psurf,Wind) are instantaneous values at the timestamp, while flux variables (Rainf,Snowf, SWdown, LWdown) are mean values over the interval ending at the timestamp. This driver also requires that the first value of the annual files corresponds to 00UTC+dt_forcing (for insatnce 03UTC for a 3hourly forcing), and that the last value is for Dec 31st at 24UTC = 00UTC on Jan 1st of the following year.     
     53* '''the old driver (src_driver/dim2driver)''', which assumes that scalar variables (Tair,Qair,Psurf,Wind) are instantaneous values at the timestamp, while flux variables (Rainf,Snowf, SWdown, LWdown) are mean values over the interval ending at the timestamp. This driver also requires that the first value of the annual files corresponds to 00UTC+dt_forcing (for instance 03UTC for a 3hourly forcing), and that the last value is for Dec 31st at 24UTC = 00UTC on Jan 1st of the following year.     
    5454* '''the new driver (src_driver/orchideedriver.f90) is more flexible''' and can normally deal with any temporal structure of the forcing datasets, provided the required attributes are inserted in the forcing files. Yet, orchideedriver is not yet compatible with libIGCM. This document [attachment:Description_Forcing_Files.pdf] provides details of how forcing files need to be prepared. It addresses in particular the issues one may face when the fluxes are averaged and scalar variables instantaneous. The driver needs to take this into account else the diurnal cycle can be misplaced. Some data providers have different convention for representing averaged fluxes and this type of details matter.  
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