SPATIAL VARIABILITY IN STABE ISOTOPES OF SNOW AND ICE FROM PERENNIAL SNOWFIELDS IN THE PACIFIC NORTHWEST

Alpine ice cores are an important source of paleoclimate information through the Quaternary, providing context for ongoing climate change. Though single ice cores are often used to represent regional climate, the spatial resolution of ice core records is uncertain. Here, we sampled snow stratigraphy from alpine perennial snowfields at Mt. Rainier and Mt. Hood in the Pacific Northwest, USA. We compared the stable isotopic composition (d18O and dD) of perennial snow field samples from multiple locations on each mountain, and compared between mountains (separated by ~170 km) to constrain spatial variability among multi-annual records. Our results reveal the spatial extent to which climate interpretations can be made based on alpine ice core records. We also use these snow records to understand the source of precipitation for Mt. Rainier and Mt. Hood and snow metamorphism that occurs within the snowpack.