Simulations for CMIP6 With the AWI Climate Model AWI‐CM‐1‐1

Tido Semmler,Helge F Goessling,Thomas Jung,Longjiang Mu,Narges Khosravi,Dmitry Sidorenko,Qiang Wang,Dmitry V Sein,Paul Gierz,Nikolay Koldunov,Thomas Rackow,Sergey Danilov,Claudia Hinrichs,Jan Hegewald

doi:10.1029/2019ms002009

Abstract

AbstractThe Alfred Wegener Institute Climate Model (AWI‐CM) participates for the first time in the Coupled Model Intercomparison Project (CMIP), CMIP6. The sea ice‐ocean component, FESOM, runs on an unstructured mesh with horizontal resolutions ranging from 8 to 80 km. FESOM is coupled to the Max Planck Institute atmospheric model ECHAM 6.3 at a horizontal resolution of about 100 km. Using objective performance indices, it is shown that AWI‐CM performs better than the average of CMIP5 models. AWI‐CM shows an equilibrium climate sensitivity of 3.2°C, which is similar to the CMIP5 average, and a transient climate response of 2.1°C which is slightly higher than the CMIP5 average. The negative trend of Arctic sea‐ice extent in September over the past 30 years is 20–30% weaker in our simulations compared to observations. With the strongest emission scenario, the AMOC decreases by 25% until the end of the century which is less than the CMIP5 average of 40%. Patterns and even magnitude of simulated temperature and precipitation changes at the end of this century compared to present‐day climate under the strong emission scenario SSP585 are similar to the multi‐model CMIP5 mean. The simulations show a 11°C warming north of the Barents Sea and around 2°C to 3°C over most parts of the ocean as well as a wetting of the Arctic, subpolar, tropical, and Southern Ocean. Furthermore, in the northern middle latitudes in boreal summer and autumn as well as in the southern middle latitudes, a more zonal atmospheric flow is projected throughout the year.

Highlights

Around 50 institutions worldwide are participating in the current sixth phase of the Coupled Model Intercomparison Project 6 (CMIP6; Eyring et al, 2016)
Our transient climate response is with 2.1°C slightly higher compared to the CMIP5 multi‐model mean (1.9°C according to Meehl et al, 2020), slightly lower compared to the CMIP6 multi‐model mean (2.2°C according to Meehl et al, 2020), and around 23% higher than in Max Planck Institute (MPI)‐ESM (1.7°C)
Biases in Alfred Wegener Institute Climate Model (AWI‐CM) tend to be less pronounced than in models contributing to the previous Climate Model Intercomparison Project 5, as shown by objective performance indices

Summary

Introduction

Around 50 institutions worldwide are participating in the current sixth phase of the Coupled Model Intercomparison Project 6 (CMIP6; Eyring et al, 2016). Journal of Advances in Modeling Earth Systems unstructured meshes that only few institutions worldwide are employing at this stage (e.g., Korn, 2017; Petersen et al, 2019). For the set of “Evaluation and Characterization of Klima” (DECK) and ScenarioMIP experiments, a mesh with local refinement of up to 8 km in the North Atlantic Current and the Southern Ocean is used. Coupling the unstructured ocean model FESOM to ECHAM6, which is used for the MPI‐ESM contribution to CMIP6, offers the unique opportunity to investigate the influence of an alternative ocean model formulation on the results which will be exploited in further research

Objectives

Findings

Discussion

Conclusion