CAREER: Ocean-atmosphere interactions through the lens of stable water isotopologues

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

How large-scale spatial patterns of precipitation and evaporation over the oceans will vary in the future remains uncertain. This project will advance scientific understanding of the hydrologic cycle and how it is archived in key oceanic and atmospheric variables over years to centuries in the tropical Pacific. It serves as a key example of interdisciplinary research that integrates oceanic and atmospheric perspectives on the hydrologic cycle and incorporates modern observations, model simulations, and paleoclimate data. This project will also provide mentoring and training opportunities for the next generation of the geoscience workforce through an authentic research-based undergraduate course and the NSF-funded STEMSEAS (Science, Technology, Engineering and Math Student Experiences Aboard Ships) program, which provides ship-based, 6-10 day exploratory experiences for undergraduates from diverse backgrounds. The formal assessment of these activities will provide evidence for the role of faculty mentorship and authentic research experiences in knowledge attainment, the degree to which students self-identify as scientists, and how they understand the nature of science. The research goals of this project will be attained through measurement of stable oxygen and hydrogen isotope ratios in seawater, precipitation, and water vapor from Palau and the Galapagos, in the western and eastern tropical Pacific, respectively. These data will reveal the relationship between seawater stable isotope values and sea surface salinity, with implications for reconstructions of past salinity and precipitation minus evaporation (P-E) from isotope-based paleoclimate proxies. This project will also demonstrate the ability of stable isotope values in seawater and precipitation to represent zonal gradients of P-E and the Walker Circulation, necessary information for interpretation of large-scale syntheses of isotope-based paleoclimate information. Finally, it will address the nature of the evaporation signal in seawater, precipitation, and water vapor stable isotope ratios, the results of which are important for isotope-enabled hydrological simulations, isotope-based paleoclimate interpretations, and understanding the drivers of tropical marine boundary layer humidity, which has implications for clouds and climate feedbacks. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.