Reply [to [Comment on] “Comment on “New global drifter data set available’” by Ohann Lutjeharms and Isabelle Ansorge]



The Eos article referred to in the letter by Lutjeharms et al. discusses only the time mean drifter velocity data in the Agulhas Return Current region. Because of Eos space limitations, we could not discuss the large amount of research devoted to synoptic meanders and eddies, which are also seen by the individual drifter tracks in our data set while passing through the Agulhas Return Current system.

More than 10 years of drifter data were used in the time mean velocity plot in our Figure 2. Underlying the synoptic variations were seven semi-permanent meanders of the Agulhas Return Current. In our global drifter data set, no other western boundary current had such an extensive, steady or stable meander pattern. We thought that this indeed was a “discovery” and are pleased that Lutjeharms et al. agree.