  Using an idealised climate model incorporating seasonal forcing, we
investigate the impact of rotation rate on the abundance of clouds on an
Earth-like aquaplanet, and the resulting impacts upon albedo and seasonality.
We show that the cloud distribution varies significantly with season, depending
strongly on the rotation rate, and is well explained by the large-scale
circulation and atmospheric state. Planetary albedo displays non-monotonic
behaviour with rotation rate, peaking at around 1/2$\Omega_E$. Clouds reduce
the surface temperature and total precipitation relative to simulations without
clouds at all rotation rates, and reduce the dependence of total precipitation
on rotation rate, causing non-monotonic behaviour and a local maximum around
1/8$\Omega_E$ ; these effects are related to the impacts of clouds on the net
atmospheric and surface radiative energy budgets. Clouds also affect the
seasonality. The influence of clouds on the extent of the winter Hadley cell
and the intertropical convergence zone is relatively minor at slow rotation
rates ($<$1/8$\Omega_E$ ), but becomes more pronounced at intermediate rotation
rates, where clouds decrease their maximum latitudes. The timing of seasonal
transitions varies with rotation rate, and the addition of clouds reduces the
seasonal phase lag.
