CESM experiments for diverse impacts of ENSO on summertime synoptic-scale disturbance intensity over the tropical western North Pacific

Experiments are conducted using Community Atmospheric Model version 5.2 (CAM-5.2; https://www.cesm.ucar.edu/models/cesm1.1/cam/) which is the atmosphere component of Community Earth System Model (CESM) of the National Center for Atmospheric Research (NCAR). The model resolution is f19_g16, with f19 finite volume grid (1.9° latitude × 2.5° longitude) for the atmosphere and land components combined with the gx1v6 displaced pole grid (approximately 1°) for the ocean and ice components.

       Five sets of model experiments are designed in this study:

Climatological SST forcing simulation (CLM-SST run): The CAM is forced by global climatological mean monthly SST that is obtained from OI version 2 SST data for the period from January 1982 to December 2020 and integrated for 30 years.

Full SST forcing simulation (Full-SST run): The CAM is forced by global monthly OI version 2 SST and integrated from January 1982 to December 2020.

Tropical central-eastern Pacific SST forcing simulation (CEP-SST run): The CAM is forced by total monthly SST in the domain of 15°S–15°N and 160°E–80°W and climatological mean monthly SST in the other regions and integrated from January 1982 to December 2020.

Sensitivity experiments of tropical central-eastern Pacific SST anomalies: The CAM is forced by global climatological mean monthly SST from January to December plus composite JJA mean SST anomalies in El Niño and La Niña events in the tropical central-eastern Pacific (15°S–15°N, 160°E–80°W) and the above SST anomalies multiplied by -1 from May to December and integrated for 30 years. These four sensitivity experiments are referred to as CEP-EN, CEP-LN, CEP-ENrev, and CEP-LNrev, respectively.

Double tropical central-eastern Pacific SST anomalies: The CAM is forced by global climatological mean monthly SST from January to December plus composite JJA mean SST anomalies during El Niño and La Niña events over the tropical central-eastern Pacific (15°S–15°N, 160°E–80°W) multiplied by 2 from May to December and integrated for 30 years. The simulations with composite SST anomalies derived from El Niño (La Niña) are referred to as CEP-2EN (CEP-2LN) runs.