The non-hydrostatic global atmospheric model for CMIP6 HighResMIP simulations (NICAM16-S): Experimental design, model description, and sensitivity experiments

Abstract

Abstract. NICAM, a nonhydrostatic global atmospheric model with an icosahedral grid system, has been developed for nearly two decades. This paper describes NICAM16-S, the latest stable version of NICAM (NICAM.16) modified for Coupled Model Intercomparison Project Phase 6 (CMIP6). Major updates from NICAM.12, a previous version used for climate simulations, include updates of a cloud microphysics scheme and a land model, an introduction of natural and anthropogenic aerosols and a subgrid-scale orographic gravity wave drag, and improvement of coupling between cloud microphysics and radiation schemes. External forcings were updated to follow a protocol of CMIP6 High Resolution Model Intercomparison Project (HighResMIP). A series of short-term sensitivity experiments were performed to check and understand impacts of the model updates on the simulated mean states. Improvements in the ice water content, the high cloud amounts, the surface air temperature over the Arctic region, the location and the strength of zonal mean subtropical jet, and shortwave radiation over the Africa and the South Asia were found in the NICAM16-S simulations. Some long-standing biases such as the double intertropical convergence zone and smaller low cloud amounts still exist or even worsen in some cases, suggesting further necessity for understanding their mechanisms and upgrading schemes and/or their parameter settings as well as for enhancing horizontal and vertical resolutions.

Evaluation of extreme sub-daily precipitation in high-resolution global climate model simulations

“…The MRI-AGCM3-2 models were developed at the Max Planck Institute for Meteorology in Hamburg, Germany [ 37 ]. The NICAM16 models are based on non-hydrostatic equations and were developed at multiple institutions in Yokohama, Tokyo and Tsukuba, Japan [ 38 ]. Additionally, we also evaluate the Community Atmospheric Model (CAM5.1), developed at the National Center for Atmospheric Research in Boulder, Colorado, United States [ 5 , 39 ].…”

Evaluation of the contribution of tropical cyclone seeds to changes in tropical cyclone frequency due to global warming in high-resolution multi-model ensemble simulations

“…In the present study, we used the six models included in CMIP6 HighResMIP: Centre National de Recherches Meteorologiques and Cerfacs for CMIP6 (CNRM-CM6; Voldoire et al 2019); EC-Earth3P (Haarsma et al 2020); the Hadley Centre Global Environment Model 3-Global Coupled version 3.1 (HadGEM3-GC3.1; Roberts et al 2019a); the Max Planck Institute for Meteorology Earth System Model (MPI-ESM1.2; Gutjahr et al 2019); MRI-AGCM3 (Mizuta et al 2012); and the latest stable version of NICAM modified for CMIP6 (NICAM16-S; Kodama et al 2020). We abbreviated them by combining the model name and horizontal grid interval.…”

A Wall‐Like Sharp Downward Branch of the Walker Circulation Above the Western Indian Ocean

“…We use the Nonhydrostatic Icosahedral Atmospheric Model (NICAM; Satoh et al, 2008Satoh et al, , 2014Tomita & Satoh, 2004), the version of which used for our experiments is the latest stable version, NICAM16-S (Kodama et al, 2020). The condensation processes are explicitly calculated using the single moment water 6 microphysics scheme (Tomita, 2008).…”

“…To mitigate the effect of the model bias over land, the initial conditions of the land surface are taken from the monthly climatology derived from the last 5 years of a 10‐year simulation of NICAM at 220 km horizontal resolution following Kodama et al. (2015, 2020).…”

“…Time evolution of the sea surface temperature is prescribed externally from the interpolation of the NCEP-FNL data at 00 UTC on each day. To mitigate the effect of the model bias over land, the initial conditions of the land surface are taken from the monthly climatology derived from the last 5 years of a 10-year simulation of NICAM at 220 km horizontal resolution following Kodama et al (2015Kodama et al ( , 2020.…”