Context : Chemically peculiar A type ( Ap ) stars are a subgroup of the CP2 stars which exhibit anomalous overabundances of numerous elements , e.g .
Fe , Cr , Sr and rare earth elements .
The pulsating subgroup of the Ap stars , the roAp stars , present ideal laboratories to observe and model pulsational signatures as well as the interplay of the pulsations with strong magnetic fields and vertical abundance gradients .

Aims : Based on high resolution spectroscopic observations and observed stellar energy distributions we construct a self consistent model atmosphere , that accounts for modulations of the temperature-pressure structure caused by vertical abundance gradients , for the roAp star 10 Aquilae ( HDÂ 176232 ) .
We demonstrate that such an analysis can be used to determine precisely the fundamental atmospheric parameters required for pulsation modelling .

Methods : Average abundances were derived for 56 species .
For Mg , Si , Ca , Cr , Fe , Co , Sr , Pr , and Nd vertical stratification profiles were empirically derived using the DDAFit  minimization routine together with the magnetic spectrum synthesis code Synthmag .
Model atmospheres were computed with the LLmodels  code which accounts for the individual abundances and stratification of chemical elements .

Results : For the final model atmosphere T _ { eff } = 7550 K and \log ( g ) = 3.8 were adopted .
While Mg , Si , Co and Cr exhibit steep abundance gradients Ca , Fe and Sr showed much wider abundance gradients between log \tau _ { 5000 } = -1.5 and 0.5 .
Elements Mg and Co were found to be the least stratified , while Ca and Sr showed strong depth variations in abundance of up to \approx 6 Â dex .

Conclusions :