Basic performance of a new earth system model of the Meteorological Research Institute (MRI-ESM1)

Abstract

Simulations of climate, including atmospheric chemistry and carbon cycle, are conducted for the period from 1850 through 2100 with a new earth system model (ESM) of the Meteorological Research Institute (MRI), MRI-ESM1. This model has been developed as an extension of the atmosphere-ocean coupled general circulation model, MRI-CGCM3, by adding chemical and biogeochemical processes. The dynamic and thermodynamic processes are entirely the same in both models. The horizontal resolution of MRI-ESM1 is higher than that of the ozone model that handles chemical processes which require high computational cost. In the control experiment, it is confirmed that the climatic drift of the model is insignificant with regard to surface air temperature (SAT), the radiation budget, and trace gas (carbon dioxide (CO 2 ) and ozone) concentrations. Compared with a control experiment by MRI-CGCM3, SAT is slightly higher because of a higher tropospheric ozone concentration. The performance of MRI-ESM1 is validated by conducting a historical experiment. Overall, MRI-ESM1 simulates well observed historical changes in SAT and trace gas concentrations. However, increases in the SAT and atmospheric CO 2 concentration are underestimated, associated with a positive feedback process through soil respiration. Namely the underestimation of atmospheric CO 2 increase causes weak SAT rise which makes soil respiration inactive, and then the excess of net land surface CO 2 uptake suppresses increase of the atmospheric CO 2 concentration. The simulated present-day climate states of SAT, radiation fluxes, precipitation, and trace gas concentrations are also in good agreement with observations although there are errors of radiations, precipitation, and ozone concentration especially over the southern tropical Pacific in the simulation. These errors appear to be originated from the excess of convective activity: so-called double ITCZ (intertropical convergence zone). Both MRI-ESM1 and MRI-CGCM3 are similarly able to reproduce the present-day climatology. In future projections, the global mean SAT rise at the end of the 21st century relative to the pre-industrial era is 3.4°C in the experiment using the Representative Concentration Pathways 8.5 (RCP8.5) by MRI-ESM1, whereas it is 4.0°C in the MRI-CGCM3 experiment.The atmospheric CO 2 concentration projected by MRI-ESM1 for the end of the 21st century is about 800 ppm, which is lower by 130 ppm than that prescribed in the RCP8.5 experiment with MRI-CGCM3. This difference is consistent with the above-mentioned difference in the SAT rise between MRI-ESM1 and MRI-CGCM3. The global mean total column ozone increases by about 25 DU during the period from 2000 to 2100, which is comparable to that prescribed in the experiment with MRI-CGCM3. It is also investigated how aerosols simulated with a newly introduced aerosol-chemistry process influence weak SAT rise at the end of the 20th century in MRI-ESM1.

Can Climate Models Reproduce the Decadal Change of Dust Aerosol in East Asia?

“…Dust processes including dust emission, transport, and deposition are treated interactively in these models. A brief description of these 15 CMIP5 models is given in supporting information Table S1 and a more detailed description can be found in the references for these models: ACCESS1-0 Dix et al, 2013), CanESM2 (Arora et al, 2011;von Salzen et al, 2013), (Yukimoto et al, 2011(Yukimoto et al, , 2012, and MRI-ESM 1 (Adachi et al, 2013;Yukimoto et al, 2011Yukimoto et al, , 2012. Note that we select these models because dust emission fluxes are interactively calculated by these models themselves via dust emission schemes, and meanwhile, model results of dust emission fluxes are available from the CMIP5 archive.…”

Inconsistent strategies to spin up models in CMIP5: implications for ocean biogeochemical model performance assessment

“…Information on spin-up protocols and model initialization is usually not taken into account in model intercomparison studies (e.g., Andrews et al, 2013;Bopp et al, 2013;Cocco et al, 2013;Frölicher et al, 2014;Gehlen et al, 2014;Keller et al, 2014;Resplandy et al, 2013Resplandy et al, , 2015Rodgers et al, 2015;. This information, if available, can only be found separately in the reference papers of individual models (e.g., Adachi et al, 2013;Arora et al, 2011;Collins et al, 2011;Dunne et al, 2013;Ilyina et al, 2013;Lindsay et al, 2014;Romanou et al, 2013;Séférian et al, 2013Séférian et al, , 2016Tjiputra et al, 2013;Vichi et al, 2011;Volodin et al, 2010;Watanabe et al, 2011;Wu et al, 2013). The duration of spin-up simulations of CMIP5 ocean biogeochemical components spans from one hundred years (e.g., CMCC-CESM) to several thousand years (e.g., MPI-ESM-LR, MPI-ESM-MR) ( Fig.…”

“…For the concentrations of preindustrial dissolved inorganic carbon and total alkalinity, we still use GLODAP. The second stream of data was selected to be as close as possible to the "standard" evaluation procedure of skill-assessment protocols found in CMIP5 model reference papers (Adachi et al, 2013;Arora et al, 2011;Collins et al, 2011;Dunne et al, 2013;Ilyina et al, 2013;Lindsay et al, 2014;Romanou et al, 2013;Séférian et al, 2013Séférian et al, , 2016Tjiputra et al, 2013;Vichi et al, 2011;Volodin et al, 2010;Watanabe et al, 2011;Wu et al, 2013). Differences between these two streams of data are minor and are further detailed below.…”

Impact of interactive chemistry of stratospheric ozone on Southern Hemisphere paleoclimate simulation

“…We use an Earth System Model of the Meteorological Research Institute (MRI-ESM1) of the Japan Meteorological Agency [Yukimoto et al, 2011;Adachi et al, 2013]. The coupled model consists of two models: an atmosphere-ocean-aerosol general circulation model, MRI-CGCM3 [Yukimoto et al, 2012], which was used in CMIP5 experiments with the prescribed ozone, and a chemistry-climate model, MRI-CCM2 [Deushi and Shibata, 2011], that computes interactive ozone chemistry including stratospheric ozone catalytic cycles (HO x , NO x , etc.).…”