AMIP model simulations

AMIP runs examining the role of tropical SST cooling in driving the moistening hole (MH)

To assess the role of tropical forcing in driving the MH feature, we conduct two AMIP-type simulations using CAM5 (the atmospheric component of iCESM, with F19 resolution and 32 vertical levels) and ECHAM5.6 (T42 resolution with 19 vertical levels). For each model, we perform two sets of runs: (1) a control run forced with climatological SST and sea ice under fixed anthropogenic forcing, and (2) a sensitivity (“cooling”) run with the same boundary forcing and initialization, but with an imposed SST cooling anomaly added over the tropical eastern Pacific (10°S–10°N, 170°E–270°E). We integrate both experiments for 30 years in each model to assess whether the responses are robust across two distinct model physics frameworks. To mimic the observed SST cooling trend over the past 41 years, we impose an idealized cooling pattern with a maximum amplitude of −1 °C at the center that tapers to zero along the edges.

Each file contains 30 years of annual-mean fields (Z200, Z850, and lower tropospheric (650hPa to 1000hPa) specific humidity). Additional details for each variable are provided in the data header information.