The fractional contributions to the total C+ production (left) and destruction (right) rates from various chemical channels in the dayside Venusian ionosphere based on our solar minimum model calculations. Only those channels with factional contributions at any given altitude above 10% are indicated. The red, blue, and black lines stand for photon and photoelectron impact processes, as well as two-body chemical reactions, respectively. Channel notations (left): 1. CO₂ + hv → C⁺ + O⁺ (⁴S) + O + 2e; 2. CO₂ + hv → C⁺ + O₂ + e; 3. CO + hv → C⁺ + O + e; 4. C + hv → C⁺ + e; 5. CO₂ + e^* → C⁺ + O₂ + 2e; 6. CO₂ + e^* → C⁺ + O⁺(⁴S) + O + 3e; 7. He⁺ + CO → C⁺ + O + He; 8. CH⁺ + H → C⁺ + H₂; 9. ${\text{O}}_2^{+}+\text{C}\to {\text{C}}^{+}+{\text{O}}_2;10.{\text{O}}^{+}\left({}^4\text{S}\right)+\text{C}\to {\text{C}}^{+}+\text{O}$. Channel notations (right): 1. C+ + CO₂ → CO⁺ + CO; 2. C+ + H₂ → CH⁺ + H. Here “e” stands for ionospheric electrons in general and “e^*” stands for photoelectrons in particular.