The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere

Abstract

Abstract.The new Modular Earth Submodel System (MESSy) describes atmospheric chemistry and meteorological processes in a modular framework, following strict coding standards. It has been coupled to the ECHAM5 general circulation model, which has been slightly modified for this purpose. A 90-layer model setup up to 0.01 hPa was used at spectral T42 resolution to simulate the lower and middle atmosphere. With the high vertical resolution the model simulates the Quasi-Biennial Oscillation. The model meteorology has been tested to check the influence of the changes to ECHAM5 and the radiation interactions with the new representation of atmospheric composition. In the simulations presented here a Newtonian relaxation technique was applied in the tropospheric part of the domain to weakly nudge the model towards the analysed meteorology during the period 1998-2005. This allows an efficient and direct evaluation with satellite and in-situ data. It is shown that the tropospheric wave forcing of the stratosphere in the model suffices to reproduce major stratospheric warming events leading e.g. to the vortex split over Antarctica in 2002. Characteristic features such as dehydration and denitrification caused by the sedimentation of polar stratospheric cloud particles and ozone depletion during winter and spring are simulated well, although ozone loss in the lower polar stratosphere is slightly underestimated. The model realistically simulates stratosphere-troposphere exchange processes as indicated by comparisons with satellite and in situ measurements. The evaluation of tropospheric chemistry presented here focuses on the distributions of ozone, hydroxyl radicals, carbon monoxide and reactive nitrogen compounds. In spite of minor shortcomings, mostly related to the relatively Correspondence to: P. Jöckel (joeckel@mpch-mainz.mpg.de) coarse T42 resolution and the neglect of inter-annual changes in biomass burning emissions, the main characteristics of the trace gas distributions are generally reproduced well. The MESSy submodels and the ECHAM5/MESSy1 model output are available through the internet on request.

ORACLE 2-D (v2.0): an efficient module to compute the volatility and oxygen content of organic aerosol with a global chemistry–climate model

“…This aged SOA underestimation is also evident during the four seasons of the year, especially during winter (NMB = −93 %). This result may indicate that the model underestimates the atmospheric aging rate of SOA or misses processes forming highly oxidized OA, e.g., highly oxidized ELVOCs from the ozonolysis of terpenes (Ehn et al, 2014;Jokinen et al, 2016). Therefore, another useful feature of ORACLE 2-D is that detailed AMS measurements can be used to gain further insights into what causes biases and errors in its OA predictions.…”

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

“…Guenther et al (2006) estimated the annual total emissions of isoprene from biogenic origin to be 440 to 660 Tg (C) a −1 (see also Arneth et al, 2008, and references therein). All our simulations are within this range, however, these total emissions are further scaled with a factor of 0.6 to yield realistic mixing ratios of isoprene in the boundary layer (see Jöckel et al, 2006). A more detailed discussion on the isoprene scaling factor is provided by Pozzer et al (2007).…”

“…Among others, it reacts with CH 4 largely determining its atmospheric lifetime. Here, we present the simulated OH lifetime of atmospheric CH 4 at time t as a measure for the oxidising power of the atmosphere, calculated according to Jöckel et al (2006) as…”

Comparison of ECHAM5/MESSy Atmospheric Chemistry (EMAC) simulations of the Arctic winter 2009/2010 and 2010/2011 with Envisat/MIPAS and Aura/MLS observations

“…Here, we compare simulations of the Arctic winter stratosphere made with the submodel MSBM (Multi-phase Stratospheric Box Model, formerly PSC; Kirner et al, 2011Kirner et al, , 2015 of the chemistry-climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC; Jöckel et al, 2006Jöckel et al, , 2010 with observations from the Michelson Interferometer for Passive Atmospheric Soundings (Envisat/MIPAS) (Fischer and Oelhaf, 1996;Fischer et al, 2008) and the Aura Microwave Limb Sounder (Aura/MLS) (Waters et al, 2006). The submodel MSBM has been tested and optimized for the simulations of PSCs in the Antarctic (Kirner et al, 2011(Kirner et al, , 2015.…”