Does the dot notation above a variable not always mean a derivative?

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I came across the equation:

$\frac {\partial v} {\partial t}= g \dot v - \frac {v^2} r$

Where $v$ is a velocity in $\frac m s$, $r$ has units of $m$, and $g$ is gravity (units of $\frac m {s^2}$). Normally I’d expect $\dot v$ to mean “the derivative of $v$ with respect to $t$” or $\dot v = \frac {\partial v} {\partial t}$. However, if that’s the case here then the units of the equation don’t work. The only way the units work is if $\dot v$ is dimensionless.

Is there some other common meaning of the dot above $v$?

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Looking to the original paper after Love and Brownlee 1991 it seems there is a typo and that the symbol $\dot v$ is wrong

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Note that in the paper the symbol $\hat v$ has been used to indicate the velocity direction and probably the typo was originated by that.