Modeling, Laboratory and Field Studies of Patterned Ground

分类模式地面模型表明，在饱和水的反复冻土解冻过程中，某些类型是由密度驱动的瑞利自由对流引起的。规则间隔的对流单体导致底层冰锋的不均匀融化。霜冻作用导致石头被向上推，并在地面上形成一种图案，反映了底层冰锋的波纹。该奖项支持现场工作、实验室实验和模型研究，重点是获得水下多边形的图案宽度与深度比。这些将得到对水下多边形的实验室研究的支持。现场和实验室研究的一个新特点是使用红外热像仪来检测任何可见图案之前的自由对流。建模研究将支持这些分类多边形的实验研究。还将进行模拟研究，以确定由于活跃层中与自由对流有关的热传递而导致的差异融化穿透。

A model for sorted patterned ground shows that some types arise from density-driven Rayleigh free convection during thawing of water-saturated recurrently frozen soils. The regularly spaced convection cells result in an uneven melting of the underlying ice front. Frost action causes stones to be upthrusted and to form in a pattern on the ground surface that mirrors the corrugation in the underlying ice front. This award supports field work, laboratory experiments, and modeling studies focused on obtaining pattern width-to-depth ratios for underwater polygons. These will be supported by laboratory studies of underwater polygons. A novel feature of the field and laboratory studies is the use of infrared thermography to detect the free convection flows which precede any visible patterning. Modeling studies will support these experimental investigations of sorted polygons. Modeling studies will also be pursued to determine the differential thaw penetration due to the heat transfer associated with free convection in the active layer.