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nudging_ifs

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Generating atmospheric nudging files for IFS

There are currently two possible ways to create reference files for atmospheric nudging 1) by interpolating ECMWF re-analysis data or 2) by storing the atsmopheric field of an continous EC-Earth simulation.

Generating nudging reference files from ECMWF

1) Generating nudging files at ECMWF can be done using the same procedure that is required to generate initial conditios Generating atmospheric initial conditions for IFS at ECMWF. However instead of defining a list of dates a 6-hourly output has to be defined in INIBY in prepIFS. The range of the output INIBEGINDATE and INIENDDATE can not exceed one year (or just little more) because the list of dates gets too long.

2) Since only jobs generating one year can be launched the generation of nudging files can take a very long time. A way to increase the efficiency of this process is to introduce a parallel loop in the work flow of prepIFS. This has currently to be done manually. Start by creating and launching a new experiment and suspend the part of the part of initdata.

3) Get the git-repository ifs_initial_forcing and copy the script modify_play.sh to your home at ECMWF. Open the script and adapt the parameters by changing the experiment name and the number of additional loops that you want to run. This will add to the experiment the subsequent years which will run in parallel. The next step has to be performed to update the experiment in XCDP

4) Open a terminal and type cdp. Enter after this the following commands, while XXXX is the experiment name you have create

set SMS_PROG  992030
login ecgate xes 1
play -r /c3o/XXXX/longrange XXXX.play

Your experiment should after that include now in the loop the additional dates.

5) After having finished all the 6-hourly steps of the period of interest the data has to be processed and downloaded to BSC. A pre-processing script is

nudging_ifs.1508772779.txt.gz · Last modified: 2017/10/23 15:32 by obellpra