“…Observations that Titan's spin rate differs from synchronous [Lorenz et al, 2008a;Stiles et al, 2008Stiles et al, , 2010 have been explained by the exchange of angular momentum between Titan's massive atmosphere and its surface assuming the presence of a subsurface ocean [Lorenz et al, 2008a]. This exchange may lead to seasonal variations in Titan's rotation rate because the seasonal reversal of the meridional circulation produces a torque; the exact details of this interaction are still being explored [see, e.g., Tokano and Neubauer, 2005;Karatekin et al, 2008;Lorenz et al, 2008a;Mitchell, 2009;Van Hoolst et al, 2009;Goldreich and Mitchell, 2010;Tokano et al, 2011;Richard et al, 2014;Tokano et al, 2014].…”