Development of Instrumentation for Continuous Field-Based Measurements of Atmospheric and Oceanic Ar/N2, O2/N2, and CO2/N2 ratios and related isotopic tracers

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

0421546 Keeling This Major Research Instrumentation development award to Scripps Institution of Oceanography at the University of California San Diego campus provides funds for the development of a capability to make continuous, extremely high precision measurements of atmospheric Ar/N2 , O2/N2, and CO2/N2 ratios and related isotopic tracers. The goal is to use the measurement of changes in the Ar/N2 ratio, combined with other constraints on atmospheric mixing, to remotely sense the large-scale exchanges of heat between the atmosphere and ocean, thus providing an inexpensive complement to observations made by ships, floats and satellites. Rapid atmospheric mixing rates mean that a modest program of Ar/N2 observations can potentially constrain the heat exchange integrated over wide areas, such as full ocean basins or an entire hemisphere. The proposed approach uses two isotope ratio mass spectrometers, one deployed at Scripps Institution and one aboard a research vessel, to provide the geographic and temporal sampling needed to observe predicted change in isotope ratios due to changes in heat flux. The sampling procedures include a customized inlet system, and are designed to address concerns identified with errors in precision associated with flask sampling. The shipboard system will include underway collection of gases dissolved in surface sea water, and will have ten collectors spanning masses 28 to 45, providing simultaneous measurement of a number of important tracers. The broader impacts of the development are in the ability to improve global climate models, improving our ability to predict how anthropogenic inputs impact climate change. The project will also involve students and a postdoctoral investigator in a cutting edge research development. Scripps Institution of Oceanography is providing 30% of the equipment costs of the project from non-federal funds. This proposal is supported by the Division of Ocean Sciences at NSF. ***