Deep convection (DC) is a key-process of the oceanic circulation, costly to monitor in situ and under the influence of climate change. Our study is a first step toward monitoring DC from space: we investigate the feasibility of observing its variability using improved satellite altimetry. An oceanic simulation of the Mediterranean circulation was performed for the 1999–2007 period. DC interannual variability is realistically modelled, and the sea surface elevation (SSE) is in agreement with altimetry data. Numerical results show a strong correlation between the annual DC characteristics and the winter SSE. From that, we propose a method to monitor DC interannual variability and long term evolution using altimetry data. Our method, applied to the longest available altimetry series, represents correctly the interannual variability of DC in the Northwestern Mediterranean between 1994 and 2007.