level3-enso_diversity-nino_method.txt

Evaluate and compare the performance of CMIP6 models for simulating the El Niño-Southern Oscillation (ENSO) Diversity.
Requirements:
1.  ENSO Index Calculation
  Define functions to calculate standard ENSO indices:
   - Niño3 index (SST anomaly in 5°S-5°N, 150°W-90°W)
   - Niño4 index (SST anomaly in 5°S-5°N, 160°E-150°W)
   - Niño3.4 index (SST anomaly in 5°S-5°N, 170°W-120°W)
 Calculate monthly climatology and remove it to obtain anomalies
 Compute the indices for each model and observations
2. ENSO Diversity Analysis
 Implement EP (Eastern Pacific) and CP (Central Pacific) ENSO event identification
   - Use Niño method or pattern-based approaches
   - Classify historical El Niño events as EP or CP type
 Calculate the amplitude of EP events for each model
 Compute spatial patterns of SST anomalies during EP and CP events
 Calculate pattern correlation coefficients between models and observations
3. Rank the models and display them in a bar chart.
4. CMIP6 models: ACCESS-CM2, ACCESS-ESM1-5, BCC-ESM1, BCC-CSM2-MR, CAMS-CSM1-0, CAS-ESM2-0, CESM2, CIESM, CMCC-CM2-HR4, CMCC-CM2-SR5, CMCC-ESM2, CanESM5, FGOALS-f3-L, FGOALS-g3, FIO-ESM-2-0, GFDL-CM4, GFDL-ESM4, GISS-E2-2-G, GISS-E2-2-H, INM-CM5-0, IPSL-CM6A-LR-INCA, KACE-1-0-G, KIOST-ESM, MCM-UA-1-0, MIROC6 MPI-ESM-1-2-HAM, MPI-ESM1-2-LR, NESM3, NorCPM1.
5. Reference dataset: HadISST.
6. Time period: 1980-2014.