Graduate Student Hyojin Kim is interested in the water chemistry evolution through the critical zone - from rain to groundwater to streams and then eventually to oceans.

She examines how the water chemistry changes, what controls this variability, and where in the critical zone does this happen. To explore these questions, Hyojin, has documented the chemistry of groundwater and stream water using automated water samplers with a customized remote controller. 

For her research, she developed a new sample bottle design (Figure 1) for the water sampler to maintain the sample integrity for reactive elements such as Fe and Mn and published her method in Environmental Science Technology in 2012 (Kim et al. 2012). Hyojin and others are now using this new design to examine the dynamics of the primary weathering products such as major cations and Si in both groundwater and stream water. In particular, they used it to identify the controlling processes and factors that govern the water chemistry evolution (Kim et al. in revision).