In Isotope Lab, Picarro Cavity Ring down Spectrometer is used to measure the stable isotopic composition of surface water, ground water, precipitation (Snow and Rain) and Ice cores. The Picarro L2140-i isotopic water analyzer enables simultaneous measurements of δ¹⁸O, δ¹⁷O, and δD. Measurements of ¹⁷O-excess in conjunction with high precision measurements δ¹⁸O and δD enable geoscientists to enhance our understanding of present day climate and the interactions between the hydrosphere and biosphere and to help reconstruct climates of the past. The ability to quantify extremely small deviations in δ¹⁷O (i.e., ¹⁷O-excess), typically less than 0.1‰ in nature, is essential for paleoclimate, (eco) hydrology, and atmospheric science applications.