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how to simulate ENSO in CESM1_2_0 (nino3.4 index should be similar with observed)

Y

yaozhixiong@foxmail_com

Member
Hi, I want to simulate ENSO in CESM1_2_0. In detail, I want let the nino34 index calculated from output of model to be similar as observed.Some people run coupled model, which is forced by cyclical dataset, compare power spectrum of Nino-3 SST Anomalies with observed. They also compare annual and monthly sst mean with observed, and so on. But all of these cannot reflect the true SST situation, because it uses cyclical dataset. I mean, I want to get nino34 index similar with observed from 1950 - 2009.At first, I want to run compset CIAF, which uses COREv2 as inputdata, to similulate. I used ocean restart file from one couple case which has been run for 1000 years as initial condition for ocean model(compset CIAF). The ocean model was run from 1948 to 2009. I used the output to plot nino3.4 index, but it is very different with observed index. It can be seen in the attachment. The correlation coefficient between 1950 to 1980 is about 0.4. But correlation coefficient between 1950 to 2009 is very low. As we know, ENSO is an air-sea interaction.  Does it mean enso cannot be simulated correctly only in ocean model? I want to run coupled model to see it. If it is right, which compset can I use? Is B_1850_2000_CN ok? Because its inputdata is varying from year to year.Thank you very much.zhixiong 


 
U

ucas_qs

qiushi Zhang
Member
Hello, I am also trying to run composet CIAF now, may I ask how to set the forcing of IAF read from 1980.01? Is it feasible for me to spin up the branch of CIAF with composet C running for 30 years?
 
A

altuntas

Alper Altuntas
Moderator
Staff member
CIAF data stream starts from the year 1948. So, to start at year 1980, you can set RUN_STARTDATE to 0033-01-01.
 
U

ucas_qs

qiushi Zhang
Member
altuntas said:
CIAF data stream starts from the year 1948. So, to start at year 1980, you can set RUN_STARTDATE to 0033-01-01.
Click to expand...
Thank you very much for your reply! I want to use the restart file obtained after 30 years of NYF forcing (compset C) as the restart file of the CIAF, set the Run_type to branch, and then set RUN_STARTDATE to 0033-01-01 to start from 1980.01 atmospheric forcing, do you think it is feasible?
In addition, I would like to ask what is the difference between the run types hybrid and branch? I did not understand the comments in evn_run.xml about this, and I found that for the same case, using the same restart file, setting different run types (hybrid or branch), the model outputs are not the same, which confused me.
 
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