Outputs of Numerical experiments verifying the diverse interannual variability of Asian summer monsoon onset process

Introduction

We designed two sets of numerical experiments using the Community Earth System Model (CESM 1.2.2) released by NCAR to verify the SSTAs' effect on the interannual modes of ASMOP in April and May. In the atmospheric general circulation model (AGCM) experiments, we solely forced the Community Atmosphere Model version 5.3 (CAM5.3), the atmospheric component of the CESM 1.2.2, by the specific SSTAs in April–May. The AGCM control run included a 40-yr integration forced by the climatological sea surface temperature (SST) with the annual cycle. We attached the specific SSTAs to the climatological SST in each sensitivity experiment and integrated them for 40 years. The ensemble results in the last 30 years were used for analysis. By contrast, in the PACEMAKER experiments, we first integrated the CESM 1.2.2 for 200 years as a control run to exclude the evident climate shift. Afterward, the sensitivity experiments were conducted on the last 100-yr outputs of the control run, in which we nudged the April–May SSTAs in the specific domain but left the rest of the model's coupled climate system free to evolve. The last 30 members were ensembled for analysis in each PACEMAKER experiment. 

Numerical Experiment Design

In the AGCM category, we forced CAM 5.3 by warm SSTAs in the southwestern Indian Ocean (20°S-0°, 40°-80°E) in the ASMOP-PC2 experiment but by cold SSTAs in the western North Pacific (0°-20°N, 120°-160°E) in the ASMOP-PC3 experiment from April to May, respectively. Similar SSTAs were nudged in the two oceanic domains from April to May in the PACEMAKER category.

File Description

Output files were saved in the NetCDF format.

The "AGCM.tar.gz" and "PACEMAKER.tar.gz" was the compressed files of the atmospheric outputs in May in the AGCM and PACEMAKER experiments, respectively.

In each compressed file, the results of the control run (in the subfolder named "Control_Run"), ASMOP-PC2 (in the subfolder named "ASMOP-PC2"), and ASMOP-PC3 (in the subfolder named "ASMOP-PC3") sensitivity experiments were included for comparison.