GLOMAP-mode in UKCA linked to Tropospheric Chemistry (StdTrop)

This configuration involves an extension to the UKCA Standard Tropospheric Chemistry (StdTrop) scheme to additionally include tropospheric aerosol-precursor chemistry.

The StdTrop chemistry scheme describes the inorganic chemistry of Ox-NOx-HOx-CO chemistry, together with near-explicit degradation schemes for methane, ethane, propane, and acetone.

To couple StdTrop to the GLOMAP-mode aerosol scheme, StdTrop is extended to treat the degradation of sulphur dioxide, dimethylsulphide (DMS); and monoterpenes. In addition, two tracers are used to represent species which are used in aerosol nucleation and condensation processes: sulphuric acid (H$_2$SO$_4$) produced from the oxidation of SO$_2$ with the hydroxyl radical (OH); and a secondary organic species representing the condensable species from monoterpene oxidation. The simple monoterpene oxidation scheme is that used when GLOMAP is used in the chemistry transport model (see Spracklen et al., 2006). An ammonia tracer is also included.

A scheme for the oxidation of SO$_2$ within clouds by dissolved hydrogen peroxide (H$_2$O$_2$) and ozone (O$_3$) is also provided to give sulphate production rates which are used for in-cloud aerosol growth rates.

Note that, as for the StdTrop chemistry, this extended scheme (StdTrop+Aero) uses the Backward-Euler solver.

Spracklen, D. V., Carslaw, K. S., Kulmala, M., et al.: The contribution of boundary layer nucleation events to total particle concentrations on regional and global scales, Atmos. Chem. Phys., 6, 5631--5648, doi:10.5194/acp-6-5631-2006, 2006.