  The chemical inventory of hot Jupiter (HJ) exoplanets atmospheres continue to
be observed by various ground and space based instruments in increasing detail
and precision. It is expected that some HJs will exhibit strong non-equilibrium
chemistry characteristics in their atmospheres, which might be inferred from
spectral observations. We aim to model the three dimensional thermochemical
non-equilibrium chemistry in the atmospheres of the HJs WASP-39b and HD
189733b. We couple a lightweight, reduced chemical network `mini-chem' that
utilises net reaction rate tables to the Exo-FMS General Circulation Model
(GCM). We perform GCM models of the exoplanets WASP-39b and HD 189733b as case
studies of the coupled mini-chem scheme. The GCM results are then
post-processed using the 3D radiative-transfer model gCMCRT to produce
transmission and emission spectra to assess the impact of non-equilibrium
chemistry on their observable properties. Both simulations show significant
departures from chemical equilibrium (CE) due to the dynamical motions of the
atmosphere. The spacial distribution of species generally follows closely the
dynamical features of the atmosphere rather than the temperature field. Each
molecular species exhibits a different quench level in the simulations, also
dependent on the latitude of the planet. Major differences are seen in the
transmission and emission spectral features between the CE and kinetic models.
Our simulations indicate that considering the 3D kinetic chemical structures of
HJ atmospheres has an important impact on physical interpretation of
observational data. Drawing bulk atmospheric parameters from fitting feature
strengths may lead to inaccurate interpretation of chemical conditions in the
atmosphere of HJs. Our open source mini-chem module is simple to couple with
contemporary HJ GCM models without substantially increasing required
computational resources.
