Mapping Oxygen Isotopes in the North Pacific Ocean

Kailah Jenkins and Amy J Wagner, California State University Sacramento, Geology Department, Sacramento, CA, United States
Stable oxygen isotope (δ18O) and salinity measurements collected over the past 50 years have been used to create a gridded data set of seawater δ18O (LeGrande and Schmidt, 2006) that models characteristics of the water cycle. Paired δ18O and salinity measurements generally exhibit a linear relationship where the slope depends on regional conditions and is affected by river run-off and sea ice formation. The LeGrande and Schmidt (2006) gridded data set is broadly representative of the long-term mean of surface δ18O and cannot resolve near shore variability associated with seasonal δ18O and salinity variations. This project aims to contribute to the existing global gridded data set and create a geographical map of the Northern Pacific Ocean using seawater samples collected during the STEMSEAS May 2019 cruise (SKQ1913) from San Diego, CA to Seward, AK on the R/V Sikuliaq. This data is compared with GEOSECS/GEOTRACES data to determine the local δ18O-salinity relationship in contrast to the larger-scale global data set. This additional SKQ1913 data can be applied towards modeling climate change, characterizing ocean water masses and the water cycle.