  The authors argue for the hypothesis that interactive feedbacks involving
surface enthalpy fluxes are important to the dynamics of tropical intraseasonal
variability. These include cloud-radiative feedbacks as well as surface
turbulent flux feedbacks; the former effectively act to transport enthalpy from
the ocean to the atmosphere, as do the latter. Evidence in favor of this
hypothesis includes the observed spatial distribution of intraseasonal variance
in precipitation and outgoing longwave radiation, the observed relationship
between intraseasonal latent heat flux and precipitation anomalies in regions
where intraseasonal variability is strong, and sensitivity experiments
performed with a small number of general circulation and idealized models.
  The authors argue that it would be useful to assess the importance of surface
fluxes to intraseasonal variability in a larger number of comprehensive
numerical models. Such an assessment could provide insight into the relevance
of interactive surface fluxes to real intraseasonal variability, perhaps making
it possible to rule out either theoretical explanations in which surface fluxes
are crucial, or those in which they are not.
