DOI: 10.26050/wdcc/escimo2_rd2
title: RD2: EMAC CCMI-2022 free running combined hindcast and production simulation 1950-2099

description: Project: Earth System Chemistry Integrated Modelling (ESCiMo) / Chemistry-Climate Modelling Initiative (CCMI) - The consortial project ESCiMo targets on coupled chemistry-climate-simulations using the European Centre for Medium-Range Weather Forecasts – Hamburg (ECHAM)/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model.
The experiments are related to the international IGAC/APARC (formerly ICAG/SPARC) Chemistry-Climate Modelling Initiative (CCMI).
The focus is on climate change, ozone depletion, and air quality. The project aims on answering emerging questions of scientific, social and political relevance.

In phase 1, three types of reference simulations, as recommended by CCMI, have been performed: hindcast simulations (1950–2011), hindcast simulations with specified dynamics (1979–2013), i.e. nudged towards ECMWF ERA-Interim reanalysis data, and combined hindcast and projection simulations (1950–2100).
Simulations have been performed with two different nudging setups, with and without interactive tropospheric aerosol, and with and without a coupled ocean model. Two different vertical resolutions have been applied. For further information see:
- Jöckel et al., 2016: doi:10.5194/gmd-9-1153-2016
- Morgenstern et al., doi:10.5194/gmd-10-639-2017
- http://www.pa.op.dlr.de/~PatrickJoeckel/ESCiMo/

In phase 2 (CCMI-2022), a new set of reference simulations with an updated model version and with refined boundary conditions (mainly refined emission inventories) has been performed. It comprises a free-running hindcast (1950-2019), a specified dynamics hindcast (1979-2019), and an ensemble of three free running combined hindcast and projection simulations (1950-2099).

The EMAC simulations have been performed at the DKRZ through support from BMBF. DKRZ and its scientific steering committee are gratefully acknowledged for providing the HPC and data archiving resources for the consortial project ESCiMo (Earth System Chemistry integrated Modelling).
Summary: This experiment comprises an ensemble of three free-running combined hind-cast and projections simulations (1950-2099) with EMAC at T42L90MA resolution under the CCMI-2 refD2 protocol, see 
SPARC, 2021: SPARC Newsletter No. 57, July 2021, 39 pp., available at http://www.aparc-climate.org/publications/newsletter.

The 'ECHAM5 (5.3.02)' files contain variables describing the physical / meteorological state of the atmosphere as simulated by the ECHAM5 General Circulation Model and the 'tr_Ox_HOx' files contain chemical species related to ozone.

The Modular Earth Submodel System (MESSy - version is documented in the file header) is an integrated software framework for the assembly of Earth System Models (ESMs).
MESSy is a multi-institutional project.

"R" is short for "Ref" (=reference) according to the experiment protocols (in contrast to "S" for sensitivity).
"C" and "D" denote the experiments of the first (CCMI-1) and second (CCMI-2022) project phase, respectively.
Hind-cast simulations are labelled "1", and combined hind-cast and projection simulations are labelled "2".
"SD" denotes "specified dynamics" simulations.