Area enclosed by isopleth

[Kristopher Karnauskas]

Dear GrADS users,

Is there a command or script capable of computing the spatial area enclosed
by a specified isopleth (e.g. the 28C isotherm of SST)?

The archives show this question being asked twice.  The first (2002) doesn't
appear to have been responded to.  The response to the second (May 2005) was
to set gxout to grid and count the qualifying cells.  However, is there a
way to do this automatically, as it could then be looped through hundreds
of, say, weekly or monthly average maps?  This way a time series of the
"area enclosed by the 28C isotherm" could be produced... for example.

Thank you in advance,
Kris Karnauskas