| Summary: | The observed strong link between aerosol optical depth (<em>τ</em>) and cloud top pressure (<em>p</em><sub>top</sub>) has frequently been interpreted as the invigoration of convective clouds by aerosol, with increased <em>τ</em> being strongly correlated with decreases in <em>p</em><sub>top</sub> (increases in cloud top height). A strong correlation between <em>τ</em> and cloud fraction (<em>f</em><sub><em>c</em></sub>) has also been observed. Using satellite-retrieved data, here we show that <em>p</em><sub>top</sub> is also strongly correlated to <em>f</em><sub><em>c</em></sub>, and when combined with the strong sensitivity between <em>f</em><sub><em>c</em></sub> and <em>τ</em>, a large proportion of the relationship between <em>p</em><sub>top</sub> and <em>τ</em>can be reconstructed. Given the uncertainties about the influence of aerosol-cloud interactions on the <em>τ</em>-<em>f</em><sub><em>c</em></sub> relationship, this suggests that a large fraction of the <em>τ</em>-<em>p</em><sub>top</sub> correlation may not be due to aerosol effects. Influences such as aerosol humidification and meteorology play an important role and should therefore be considered in studies of aerosol-cloud interactions.
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