Earth System Chemistry integrated Modelling (ESCiMo) with the Modular Earth Submodel System (MESSy) version 2.51

Abstract

Abstract. Three types of reference simulations, as recommended by the Chemistry-Climate Model Initiative (CCMI), have been performed with version 2.51 of the European Centre for Medium-Range Weather Forecasts -Hamburg (ECHAM)/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model: hindcast simulations , hindcast simulations with specified dynamics , i.e. nudged towards ERA-Interim reanalysis data, and combined hindcast and projection simulations . The manuscript summarizes the updates of the model system and details the different model set-ups used, including the on-line calculated diagnostics. 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. The on-line calculated sources and sinks of reactive species are quantified and a first evaluation of the simulation results from a global perspective is provided as a quality check of the data. The focus is on the intercomparison of the different model set-ups. The simulation data will become publicly available via CCMI and the Climate and Environmental Retrieval and Archive (CERA) database of the German Climate Computing Centre (DKRZ). This manuscript is intended to serve as an extensive reference for further analyses of the Earth System Chemistry integrated Modelling (ESCiMo) simulations.

The Chemistry Climate Model ECHAM6.3-HAM2.3-MOZ1.0

“…7.65 years falls between our lght*2 and lght*4 simulations if we apply the same method as Jöckel et al (2016). Given that their lightning NO x emissions were about 4 Tg(N) yr −1 during this period, the agreement is remarkable.…”

“…With 4.8 Tg(N) yr −1 as global lightning source, the CH 4 lifetime is 8.28 years, which is more than two standard deviations below the observational constraints from either Prinn et al (2005) or Prather et al (2012). However, our CH 4 lifetime appears rather consistent with the lifetime of Jöckel et al (2016), who use a different method for the calculation (see footnote a of Figure re-generated from data described in Krefting (2017).…”

“…A further hint in this direction is given by Stevens et al (2013), who pointed out that both ECHAM5 (which forms the basis of the EMAC model reported by Jöckel et al (2016)) and ECHAM6 (the basis of ECHAM-HAMMOZ as described here) have a tropical precipitation bias of up to 5 mm day −1 .…”

“…For comparison, multi-model mean values from Stevenson et al (2006) and Young et al (2013) and Naik et al (2013) and the "GEOS5" budget terms from Lamarque et al (2012) a Computed as whole atmosphere burden of CH4 over tropospheric loss of CH4 as in Naik et al (2013). Values in parantheses were computed according to Jöckel et al (2016) 6 Global budgets…”

Solar forcing for CMIP6 (v3.2)

“…Providing a first assessment of implications employing the SSI recommended for CMIP6 in comparison to CMIP5, we present results of two state-of-the-art chemistry-climate models (CCMs): the Whole Atmosphere Community Climate Model (CESM1(WACCM); Marsh et al, 2013) and the ECHAM/MESSy atmospheric chemistry model (EMAC; Jöckel et al, 2010Jöckel et al, , 2016. Additionally, we include results of single-profile radiative transfer calculations performed with the line-by-line radiative transfer code "libradtran" (Mayer and Kylling, 2005).…”