def get_geophysical_variables(ds):
parameters = []<EOL>for variable in ds.variables:<EOL><INDENT>if is_geophysical(ds, variable):<EOL><INDENT>parameters.append(variable)<EOL><DEDENT><DEDENT>return parameters<EOL>
Returns a list of variable names for the variables detected as geophysical
variables.

:param netCDF4.Dataset nc: An open netCDF dataset