| Back to Diagnostics Plots | Methodology and Definitions |
General Notes
| Source Code | See GitHub. The Program for Climate Model Diagnosis & Intercomparison (PCMDI) Metrics Package (PMP) emphasizes metrics of large- to global-scale annual cycle and both tropical and extra-tropical modes of variability. The package expects model data to be CF-compliant. Sample usage: PMP Website. |
| Reference | The observations used were collected and processed by the E3SM Diagnostics. More info: Documentation. |
| Workflow | The diagnostics were generated using the E3SM-zppy workflow. |
Summary Metrics
| Mean Climate | Mean climate summary statistics. See PMP mean climate webpage. |
| EMoV Metrics | Summary metric for extra-tropical modes of variability (EMoV). See PMP EMoV webpage. |
| ENSO Metrics | Summary metric for El Niño–Southern Oscillation (ENSO). See PMP ENSO webpage. |
| Method | Summary metrics are featured with Portrait Plot and Parallel Coordinate Plot. |
| References | See PMP Metrics webpage. |
El Niño–Southern Oscillation (ENSO)
| Region | Diagnostics are based on monthly anomalies in the Niño 3.4 region (5°S–5°N, 170°–120°W). |
| ENSO Perf | Performance collection (15 metrics) covering: (a) background climatology (double ITCZ, equator too dry, cold tongue bias, shifted trade winds); (b) basic ENSO characteristics (amplitude, skewness, seasonality, SSTA pattern, lifecycle, duration, diversity). |
| ENSO Proc | Processes collection (11 metrics) covering: (a) background climatology (cold tongue bias, shifted trade winds); (b) basic characteristics (amplitude, skewness, seasonality, SSTA pattern); (c) feedbacks (SSH–SST, SST–heat fluxes, SST–τx, τx–SSH); (d) ocean-driven SST change. |
| ENSO Telec | Teleconnections collection (7 metrics) covering: (a) basic characteristics (amplitude, seasonality, SSTA pattern); (b) ENSO-related anomalies (precipitation and surface temperature) outside the equatorial Pacific during events. |
| Method | Developed by the ENSO Metrics Working Group of the International CLIVAR Pacific Panel. |
| References | See the ENSO metrics documentation for algorithms and examples. |
Extra-Tropical Modes of Variability (EMoV)
| NAM | Northern Annular Mode. 1st EOF mode of PSL over 20–90°N, 0–360°. |
| PNA | Pacific–North American pattern. 1st EOF mode of PSL over 20–85°N, 120°E–120°W. |
| NPO | North Pacific Oscillation. 2nd EOF mode of PSL over 20–85°N, 120°E–120°W. |
| NAO | North Atlantic Oscillation. 1st EOF mode of PSL over 20–80°N, 40°E–90°W. |
| SAM | Southern Annular Mode. 1st EOF mode of PSL over 20–90°S, 0–360°. |
| PSA1 | Pacific–South American pattern 1. 2nd EOF mode of PSL over 20–90°S, 0–360°. |
| PSA2 | Pacific–South American pattern 2. 3rd EOF mode of PSL over 20–90°S, 0–360°. |
| PDO | Pacific Decadal Oscillation. 1st EOF mode of SST over the North Pacific (poleward of 20°N). |
| NPGO | North Pacific Gyre Oscillation. 2nd EOF mode of SST over the Northeast Pacific. |
| AMO | Atlantic Multidecadal Oscillation, typically derived from detrended North Atlantic SST averages (method varies by index). |
| Method | The Common Basis Function (CBF) approach is employed in addition to traditional EOFs, projecting model anomalies onto observed modes. |
| References | See the EMoV metrics documentation. |
Mean Climate
| Mean Bias | Climatological annual/seasonal mean differences between model and observations. |
| RMSE | Root-Mean-Square Error (L2 norm) against observations/reanalyses for seasonal and mean-state climatologies. |
| Centered RMSE | RMSE of anomalies after removing the mean bias. |
| Region | Metrics computed over global, hemispheric, tropical, extra-tropical, and other selected domains. |
| References | See PMP mean climate. |