论文标题
高和干燥：火星上河流气候的十亿年趋势
High and dry: billion-year trends in the aridity of river-forming climates on Mars
论文作者
论文摘要
火星的干直线过渡是一场主要的环境灾难，但是空间模式，节奏和干燥原因受到限制。我们建立了一个全球分布的数据库，该数据库相对于流域（干旱指数），在火星后期的旧生态大小（干旱指数）上建立了限制，并在火星干燥时找到了气候分区的证据。南部中纬度地区随着时间的流逝增加了干旱，湖泊与现代内华达州一样小。同时，间歇性的潮湿气候在赤道和北部中间的低地持续存在。这与火星温室效应的变化是一致的，火星温室的效应使高地太冷了，除非在短暂的融化季节，否则火星地下水桌下降。数据与干旱指数对高程的依赖性（从高潮到早期到高潮的依赖性）的转换是一致的。随着表面条件变得越来越强调生命，这些结果使我们对火星气候的看法更加清晰。
Mars' wet-to-dry transition is a major environmental catastrophe, yet the spatial pattern, tempo, and cause of drying are poorly constrained. We built a globally-distributed database of constraints on Mars late-stage paleolake size relative to catchment area (aridity index), and found evidence for climate zonation as Mars was drying out. Aridity increased over time in southern midlatitude highlands, where lakes became proportionally as small as in modern Nevada. Meanwhile, intermittently wetter climates persisted in equatorial and northern-midlatitude lowlands. This is consistent with a change in Mars' greenhouse effect that left highlands too cold for liquid water except during a brief melt season, or alternatively with a fall in Mars' groundwater table. The data are consistent with a switch of unknown cause in the dependence of aridity index on elevation, from high-and-wet early on, to high-and-dry later. These results sharpen our view of Mars' climate as surface conditions became increasingly stressing for life.
