Observed and modeled FUV spectra for two regions in PJ10. Upper panel: observed (red) and modeled (blue) FUV spectra for the region shown in the left panel of Fig. 7. The best fit is obtained with E₀ = 54.23 keV and adjustment factors F_CH4 = 2.0, F_C2H2 = 0.3, F_C2H6 = 0.4. This fit requires a CH₄ enhancement and C₂H₂ depletion, suggesting a local atmospheric anomaly. Lower panel: observed (red) and modeled (blue) spectra for the region in the right panel of Fig. 7. The best fit is obtained with E₀ = 15 keV and adjustment factors F_CH4 = 1.0, F_C2H2 = 1.0, and F_C2H6 = 1.0. This configuration is consistent with the model atmosphere.