DOI: 10.5061/dryad.nvx0k6f10
title: Overriding hindcast experimental results in MIROC6 climate model

description: To examine the impact of winter NPO on subsequent ENSO development, we
 perform the identical-twin hindcast experiments taking the two ensemble
 members from the large ensemble historical simulations as a reference. In
 our overriding experiments, we rerun each ENSO event by applying NPO
 forcings with different intensities. Five different levels of NPO forcing
 are considered: no NPO forcing, 0.5 times NPO forcing, 1.0 times NPO
 forcing, 2.0 times NPO forcing, and 3.0 times NPO forcing. For El Niño
 events, five levels of positive NPO forcing are applied in the preceding
 winter, labeled as EXP-Clm, EXP-0.5P, EXP-1.0P, EXP-2.0P, and EXP-3.0P.
 Similarly, experiments for La Niña/-NPO events are labeled as EXP-Clm,
 EXP-0.5N, EXP-1.0N, EXP-2.0N, and EXP-3.0N, representing five intensities
 of negative NPO forcing.
description: # Overriding hindcast experimental results in MIROC6 climate model
 [https://doi.org/10.5061/dryad.nvx0k6f10](https://doi.org/10.5061/dryad.nvx0k6f10) ## Description of the data and file structure Numerical experiments are conducted using MIROC6 climate model. To quantify the impact of the winter NPO on the subsequent ENSO evolution, we use the first two members from the MIROC6 large-ensemble as a reference. We identify 17 El Niño/+NPO and 15 La Niña/-NPO events in these two members and these events are averaged to create the NPO-related atmospheric anomalies. We then rerun each ENSO event starting from January 1st of year(-1) with the same initial condition as its original historical simulations and override the surface heat flux and wind stress anomalies over the North Pacific with the composite anomalies taken from two-members historical simulations for five months from November 1st of Year(-1) to March 31st of Year(0). ### Description of the data and file structure #### File: EXP-Clm-El\_Nino-mem1.zip **Description:** 10 El Nino events in member 1 are rerun with the NPO forcing is removed. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-0.5P-El\_Nino-mem1.7z **Description:** 10 El Nino events in member 1 are rerun with 0.5 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-1.0P-El\_Nino-mem1.zip **Description:** 10 El Nino events in member 1 are rerun with 1.0 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-2.0P-El\_Nino-mem1.zip **Description:** 10 El Nino events in member 1 are rerun with 2.0 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-3.0P-El\_Nino-mem1.zip **Description:** 10 El Nino events in member 1 are rerun with 3.0 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-Clm-La\_Nina-mem1.zip **Description:** 10 La Nina events in member 1 are rerun with the NPO forcing is removed. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-0.5N-La\_Nina-mem1.zip **Description: ** 8 La Nina events in member 1 are rerun with 0.5 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-1.0N-La\_Nina-mem1.zip **Description:** 8 La Nina events in member 1 are rerun with 1.0 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-2.0N-La\_Nina-mem1.zip **Description:**  8 La Nina events in member 1 are rerun with 2.0 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-3.0N-La\_Nina-mem1.zip **Description:**  8 La Nina events in member 1 are rerun with 3.0 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-Clm-El\_Nino-mem2.zip **Description:** 7 El Nino events in member 2 are rerun with the NPO forcing is removed. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-0.5P-El\_Nino-mem2.zip **Description:** 7 El Nino events in member 2 are rerun with 0.5 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-1.0P-El\_Nino-mem2.zip **Description:** 7 El Nino events in member 2 are rerun with 1.0 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-3.0P-El\_Nino-mem2.zip **Description:** 7 El Nino events in member 2 are rerun with 3.0 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-2.0P-El\_Nino-mem2.zip **Description:** 7 El Nino events in member 2 are rerun with 2.0 times NPO forcing. The output of each El Niño event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-1.0N-La\_Nina-mem2.zip **Description:**  6 La Nina events in member 2 are rerun with 1.0 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-0.5N-La\_Nina-mem2.zip **Description:** 6 La Nina events in member 2 are rerun with 0.5 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-2.0N-La\_Nina-mem2.zip **Description:** 6 La Nina events in member 2 are rerun with 2.0 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-Clm-La\_Nina-mem2.zip **Description:** 6 La Nina events in member 2 are rerun with the NPO forcing is removed. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. #### File: EXP-3.0N-La\_Nina-mem2.zip **Description:** 6 La Nina events in member 2 are rerun with 3.0 times NPO forcing. The output of each La Nina event is stored in a folder named 'y' followed by the year in which it occurs. **Each folder has the same list of variable outputs from the previous year to the following year of each ENSO event. The following variables are used for the data analysis and are included in each folder.** evap: surface_upward_latent_heat_flux sens: surface_upward_sensible_heat_flux slp: air_pressure_at_sea_level slrd: surface_downwelling_longwave_flux_in_air ssrd: surface_downwelling_shortwave_flux_in_air sst: sea_water_temperature taux: zonal wind stress tauy: meridional wind stress u10: zonal wind at 10m v10: meridional wind at 10m ## Code/software These datasets are in NetCDF format, you can use either NCL (NCAR Command Language) or Python to open them.