[1] The hydrodynamic characteristics of mesoscale eddies of the southern Gulf of California are described from observations made in August 2004. Vertical profiles tõ 1000 m were made with a conductivity-temperature-depth (CTD) probe with dissolved oxygen and fluorescence sensors, and a lowered acoustic Doppler profiler. The four sampled eddies were aligned along the Gulf axis and had alternating sense of rotation. The Okubo-Weiss parameter was used to calculate the eddy core radii, and it also revealed that the current field of almost all the sampled area was eddy dominated. The mean radii of the eddy cores varied between 32 and 36 km. Maximum surface velocities were 0.4-0.5 m/s. The anticyclonic eddies were 500-700 m deep, while the cyclones were 450-500 m deep. The depression of the isolines associated with the anticyclonic eddies was~100 m at depths between 200 and 400 m; however, the thermocline/pycnocline, which spanned from~20 to 75 m, was domed by~10 m. The cyclonic eddies lifted the isolines by~70 m at depths above 500 m, but the isolines were flat above~60 m. This suggests that different dynamics operate in the layer above the strong and shallow pycnocline. In particular, the wind stress curl can affect circulation and pycnocline topography and, therefore, the patterns that appear in chlorophyll satellite images. In our case, the eddies were detectable in those images because of the chlorophyll-enhanced streamers along their edges and, for anticyclones, probably because the chlorophyll maximum found at 40-50 m depth was domed following the pycnocline.Citation: Lavı´n, M. F., R. Castro, E. Beier, and V. M. Godı´nez (2013), Mesoscale eddies in the southern Gulf of California during summer: Characteristics and interaction with the wind stress,