The researchers conducted experiments to study how water changes when it evaporates at different temperatures. They found that the isotopic composition of water can change during evaporation, with hydrogen isotopes being enriched more than oxygen isotopes. The temperature at which evaporation occurs can affect how much the isotopes change. The initial isotopic values of the water don't have a big impact on the evaporation process. This research helps us understand how water isotopes change when they evaporate.