DMI Report 21-33 Strengthening DMI's contribution to CMIP6 and climate change assessment

Abstract

Assessment of the projected future climate change relies on experiments using complex climate models (i.e., Earth System Models) that can realistically represent the Earth climate system. In this work package we made great efforts to enhance our capability in climate modelling using the family of the EC-Earth3 Earth System Model, and to increase our contribution to the international Coupled Model Intercomparison Project phase 6 (CMIP6). The contributions include performing another set of climate change simulations for the historical period (https://www.dmi.dk/fileadmin/Rapporter/2021/DMI_Report_21-33.pdf1850-2014) followed by four future scenarios (i.e., SSP5-8.5, SSP3-7.0, SSP2-4.5, SSp1-2.6, respectively) using the Earth System Model EC- Earth3-Veg; Extending the climate change simulation under the high-end emission scenario SSP5- 8.5 to year 2300; and performing the new CMIP6-endorsed CovidMIP aiming at assessing the climate impact of the emission reduction due to COVID19 pandemic. Archiving the CMIP6 experiment data following the CMIP6 standards and compliance on the Earth System Federation Grid (ESGF) data nodes is important to ensure the contribution to CMIP6 is available for scientists worldwide to access the data for a variety of applications from assessment and understanding of climate change, to studies of climate impacts and mitigation. We have worked a great deal to prepare the above mentioned and other CMIP6 simulation data for publishing on the DMI's ESGF data node. The processes involve in reformatting the simulation data into the CMIP standard and quality control the reformatted data to ensure their correctness. With our efforts and contributions to CMIP6, we have joined several multi-model multi-member ensemble analyses using the CMIP6 experiment ensembles. We have quantified the future climate changes under variety of future scenarios, and analyzed climate response to the COVID19 related emission reduction. We have also participated in the documentation of the EC-Earth3 model development and performance. These studies have led to a number of scientific papers. We foresee our contributed simulation ensembles, as subsets in the CMIP6 experiment ensembles, have contributed and will continue to contribute to many climate change assessments and studies for many years ahead. www.dmi.d