Figure 4. Correlations between ΔpH_a and RR (Δ[HCO₃ ⁻]_a)/$\mathrm{\Delta }{P}_{{\mathrm{aCO}}_2}$) with ascent to high altitude.

A, 3440 m, day 3. B, 3820 m, day 5. C, 4240 m, day 7. D, 5160 m, day 10. Correlation coefficients (r), P values, slope of the linear response and n are reported in each case. Delta values at each altitude are compared to baseline values (see Eqn (2)). Days reported represent days of altitude exposure.