The facility serves as the principal home for several staff members with additional research activities that are supported by other funds.

John Hayes (retired director of NOSAMS), maintains a program of research in isotopic biogeochemistry. Since 1998, it has resulted in many peer-reviewed publications which are listed in the bibliography below. Topics include studies of carbon- and hydrogen-isotopic fractionations imposed by phytoplankton and other microorganisms, paleoenvironmental studies based on sedimentary isotopic and organic-geochemical records, studies of the anaerobic oxidation of methane in marine sediments, the long-term record of ¹³C in sedimentary organic carbon, and developments in stable-isotopic analytical techniques. On-going research supported by non-NOSAMS funds includes many of those topics as well as studies of ¹⁴C as an inverse tracer for fossil-fuel-derived organic materials in modern environments (with T. Eglinton and C. Reddy) and studies of the transport and sedimentation of biomarkers of paleoclimatic interest (with T. Eglinton and J. McManus).

Richard Healy, an information systems associate and manager of the NOSAMS computer network and web site, collaborates with the NASA/Goddard Institute for Space Studies (GISS) climate-modeling group in New York. One aspect of the research is modeling for the Analysis of Recent and Rapid Climate Change (ARRCC) program. Working with the GISS general circulation model, the observed sunspot activity during the past 500 years has been used to estimate changes in solar irradiance and their correlation with changes in global surface air temperature (Robertson et al., 2001)


Ann McNichol, the staff chemist and director of the sample-preparation laboratory, is studying the distribution of ¹³C in oceanic DIC in order to understand the ocean’s role in the uptake of fossil-fuel-derived CO₂ and to examine other processes in the carbon cycle. Her work follows earlier examinations of the fate of anthropogenic CO₂ in the oceans (Quay et al., 1992; Heimann and Maier-Reimer, 1996; Tans et al., 1993) and updates them through use of the extensive data set of δ¹³C values collected during the analyses of the WOCE samples at NOSAMS.

Mark Roberts, staff physicist is working on an initiative to re-determine the ¹⁴C half-life. This initiative was developed in response to questions raised by various researchers at Lamont-Doherty Earth Observatory (Broecker, 2005; Fairbanks, 2005; Chiu, 2007), who pointed to uncertainties about the validity of the 'accepted' 14C half-life. These groups suggested that the currently accepted half-life of 5700 ± 30 years might be too low. A significant shift in the ¹⁴C half-life would impact our understanding of the ¹⁴ C calibration curve. Preliminary results, in which the ¹⁴C half-life is determined from knowledge of both the specific-activity and ¹⁴C/¹²C ratio of the ¹⁴C counting standard OX-I, indicate that the currently accepted half-life might actually be 1-2% too high. A paper summarizing the work has been recently accepted for publication in Radiocarbon.

References
Broecker W and Barker S, (2005) ‘A 190 per mil drop in atmosphere’s Δ¹⁴C during the “Mystery Interval” (17.5 to 14.5 kyrs)?’, submitted to Quaternary Science Reviews.

Fairbanks RG, Mortlock RA, Chiu T-C, Cao L, Kaplana A, Guilderson TP, Fairbanks TW, Bloom AL, Grootes PM, and Nadeau M-J, (2005) ‘Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired ²³⁰Th/²³⁴ U/²³⁸ U and ¹⁴C dates on pristine corals, Quaternary Science Reviews 24, 1781–1796.

Chiu T-C, Fairbanks RG, Cao L, and Mortlock RA, (2007) ‘Analysis of the atmospheric ¹⁴C record spanning the past 50,000 years derived from high-precisions ²³⁰Th/²⁴⁴U/²³⁸U, ²³¹Pa/²³⁵U and ¹⁴C dates on fossil corals’, Quaternary Science Reviews 26, 18-36