  The climates of terrestrial planets with a small amount of water on their
surface, called land planets, are significantly different from the climates of
planets having a large amount of surface water. Land planets have a higher
runaway greenhouse threshold than aqua planets, which extends the inner edge of
the habitable zone inward. Land planets also have the advantage of avoiding
global freezing due to drier tropics, leading to a lower planetary albedo. In
this study, we systematically investigate the complete freezing limit for
various surface water distribution using a three-dimensional dynamic
atmospheric model. As in a previous study, we found that a land planet climate
has dry tropics that result in less snow and fewer clouds. The complete
freezing limit decreases from that for aqua planets (92% S0, where S0 is
Earth's present insolation) to that for land planets (77% S0) with an
increasing dry area. Values for the complete freezing limit for zonally uniform
surface water distributions are consistently lower than those for meridionally
uniform surface water distribution. This is because the surface water
distribution in the tropics in the meridionally uniform cases causes ice-albedo
feedback until a planet lapses into the complete freezing state. For a surface
water distribution using the topographies of the terrestrial planets, the
complete freezing limit has values near those for the meridionally uniform
cases. Our results indicate that the water distribution is important for the
onset of a global ice-covered state for Earth-like exoplanets.
