  Thermal dissociation and recombination of molecular hydrogen, H_2, in the
atmospheres of ultra-hot Jupiters (UHJs) has been shown to play an important
role in global heat redistribution. This, in turn, significantly impacts their
planetary emission, yet only limited investigations on the atmospheric effects
have so far been conducted. Here we investigate the heat redistribution caused
by this dissociation/recombination reaction, alongside feedback mechanisms
between the atmospheric chemistry and radiative transfer, for a planetary and
stellar configuration typical of UHJs. To do this, we have developed a
time-dependent pseudo-2D model, including a treatment of time-independent
equilibrium chemical effects. As a result of the reaction heat redistribution,
we find temperature changes of up to $\sim$400 K in the atmosphere. When TiO
and VO are additionally considered as opacity sources, these changes in
temperature increase to over $\sim$800 K in some areas. This heat
redistribution is found to significantly shift the region of peak atmospheric
temperature, or hotspot, towards the evening terminator in both cases. The
impact of varying the longitudinal wind speed on the reaction heat distribution
is also investigated. When excluding TiO/VO, increased wind speeds are shown to
increase the impact of the reaction heat redistribution up to a threshold wind
speed. When including TiO/VO there is no apparent wind speed threshold, due to
thermal stabilisation by these species. We also construct pseudo-2D phase
curves from our model, and highlight both significant spectral flux damping and
increased phase offset caused by the reaction heat redistribution.
