Overview of climate change in the BESM-OA2.5 climate model

• Main Authors: Capistrano, Vinicius Buscioli, Nobre, Paulo, Tedeschi, Renata, Silva, Josiane, Bottino, Marcus, Silva Jr., Manoel Baptista, Menezes Neto, Otacílio Leandro, Figueroa, Silvio Nilo, Bonatti, José Paulo, Kubota, Paulo Yoshio, Reyes Fernandez, Julio Pablo, Giarolla, Emanuel, Vial, Jessica, Nobre, Carlos A.
• Format: Text
• Language: English
• Published: 2018
• Subjects: Antarctic; Arctic; The Antarctic; Antarc*; Climate change
• Online Access: https://doi.org/10.5194/gmd-2018-209; https://www.geosci-model-dev-discuss.net/gmd-2018-209/

The main features of climate change patterns, as simulated by the coupled ocean-atmosphere version 2.5 of the Brazilian Earth System Model (BESM-OA2.5) are contrasted with those of other 25 CMIP5 models, focusing on temperature, precipitation and atmospheric circulation. The climate sensitivity to quadrupling atmospheric CO 2 concentration is investigated from two techniques: Gregory et al. (2004) and Radiative Kernel (Soden and Held, 2006; Soden et al., 2008) methods. Radiative kernels from both NCAR and GFDL are used in order to decompose the climate feedback responses of CMIP5 models and BESM-OA2.5 into different processes. Applying the Gregory method for equilibrium climate sensitivity (ECS) estimation, we obtain values ranging from 2.07 to 4.74 K for the CMIP5 models and 2.96 K for BESM, which is close to the ensemble mean value (3.30 K ± 0.76). The study reveals that BESM has shown zonally averaged feedbacks estimated from Radiative Kernel within the ensemble standard deviation of the other CMIP5 models. The exceptions are found in the high-latitudes of the Northern Hemisphere, where BESM shows values for lapse-rate and humidity feedbacks marginally out of the limit between minimum and maximum of CMIP5 multi-model ensemble, as well as in the Arctic region and over the ocean near the Antarctic for cloud feedback. Moreover, BESM shows physically consistent changes in the pattern of temperature, precipitation and atmospheric circulation.