Collaborative Research on Development and Evaluation of Continuously Weighing Minilysimeters

由于难以确定热量和水分传输的微尺度变化，对小气候学模式和过程的研究一直受到阻碍。其中最重要的变量是通过蒸发和蒸腾作用将水蒸气从地面和植被转移到空气中。蒸渗仪已被开发用于直接测量蒸散量，但这些仪器体积大、固定、价格昂贵，只能对其覆盖区域的读数进行平均。这一合作研究项目将改进和测试一套微型仪器，以测量热量和水分传输的空间变化。三个连续称重的便携式微型测量仪将被设计并在一个精心控制的实验中进行测试，该实验将把它们的测量结果与使用三种不同的微气候学方法获得的记录进行比较。该项目将确定小型便携式微型测量仪在多大程度上可以用来准确测量各种不同地点的蒸散量。这些测试将有助于确定这些工具将在何种条件下发挥作用，以及使用它们收集的数据的信心。由于有可能使用这类仪器来提供迄今无法获得的关于热量和水分传输中微尺度空间变异性的信息，该项目应该对小气候学研究的进展做出重大贡献。

Inquiries into microclimatological patterns and processes have been inhibited by difficulties in determining micro-scale variations in heat and moisture transfers. Among the most important variables are transfers of water vapor through evaporation and transpiration from ground surfaces and vegetation into the air. Lysimeters have been developed to directly measure evapotranspiration, but these machines are large, stationary, expensive, and capable only of averaging readings over the area that they cover. This collaborative research project will refine and test a set of minilysimeters to measure spatial variations in the transfer of heat and moisture. Three continuously weighing, portable minilysimeters will be designed and tested in a carefully controlled experiment that will compare their measurements with records obtained using three alternative microclimatological approaches. This project will determine the extent to which small, portable minilysimeters can be used to accurately measure evapotranspiration in a variety of different sites. These tests will help ascertain the conditions in which these instruments will be useful and the confidence with which the data that they collect can be used. Because of the potential for using instruments of this type to provide heretofore unavailable information about micro-scale spatial variability in heat and moisture transfer, the project should contribute significantly toward advancement of microclimatological research.