English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Climate projections including chemical feedbacks rely on state-of-the-artchemistry–climate models (CCMs). Of particular importance is the role ofmethane (CH4) for the budget of stratospheric water vapour (SWV),which has an important climate impact. However, simulations with CCMs are, dueto the large number of involved chemical species, computationally demanding,which limits the simulation of sensitivity studies. To allow for sensitivity studies and ensemble simulations with a reduceddemand for computational resources, we introduce a simplified approach tosimulate the core of methane chemistry in form of the new Modular EarthSubmodel System (MESSy) submodel CH4. It involves an atmosphericchemistry mechanism reduced to the sink reactions of CH4 with predefinedfields of the hydroxyl radical (OH), excited oxygen (O(1D)), andchlorine (Cl), as well as photolysis and the reaction products limitedto water vapour (H2O). This chemical production of H2O isoptionally fed back onto the specific humidity (q) of the connectedgeneral circulation model (GCM), to account for the impact ontoSWV and its effect on radiation and stratospheric dynamics. The submodel CH4 is further capable of simulating the four most prevalentCH4 isotopologues for carbon and hydrogen (CH4 and CH3D, aswell as 12CH4 and 13CH4). Furthermore, theproduction of deuterated water vapour (HDO) is, similar to theproduction of H2O in the CH4 oxidation, optionally passed back tothe isotopological hydrological cycle simulated by the submodel H2OISO,using the newly developed auxiliary submodel TRSYNC. Moreover, thesimulation of a user-defined number of diagnostic CH4 age and emissionclasses is possible, the output of which can be used for offline inverse optimizationtechniques. The presented approach combines the most important chemical hydrologicalfeedback including the isotopic signatures with the advantages concerning thecomputational simplicity of a GCM, in comparison to a full-featuredCCM.

Methane chemistry in a nutshell – the new submodels CH4 (v1.0) and TRSYNC (v1.0) in MESSy (v2.54.0)