Marine Chemistry special issue: The renaissance of radium isotopic tracers in marine processes studies

摘要

Four radium isotopes, decay products of the ~(238)U-~(232)Th-~(235)U series radionuclides, occur in nature: ~(224)Ra (t_(1/2)=3.66 days), ~(223)Ra (t_(1/2) = 11.4 days), ~(228)Ra (t_(1/2) = 5.75 years), and ~(226)Ra (t_(1/2)=1600 years). Beginning with the GEOSECS program of the late 1960s-early 1970s, these radium isotopes have been widely applied to the study of a variety of oceanographic processes (Moore, 1972; Trier et al., 1972). In the GEOSECS era, upper-ocean and bottom boundary layer mixing were quantified using ~(228)Ra (Sarmiento et al., 1976). Coastal ocean mixing was a notable application of the radium quartet in the 1980s (Moore, 1987).