Cosmogenic radiocarbon production and glacial cycles control marine radiocarbon archive variations
En palabras de los autores
Abstract Marine radiocarbon archives are depleted relative to the atmosphere, which is commonly expressed as the marine radiocarbon reservoir age. Here we apply an Earth system model of intermediate complexity equipped with radiocarbon to simulate marine reservoir ages over the past 50,000 years. Globally, our simulated reservoir ages range from 400 to 1200 years at the sea surface and are systematically lower than previous uncoupled model estimates. This is mainly due to stronger vertical mixing and air sea exchange rates of carbon dioxide in our model. Short-term reservoir age variations are dominated by changes in cosmogenic radiocarbon production, while glacial-interglacial climate variations exert slower and damped effects. According to our model, the interhemispheric radiocarbon gradient in the atmosphere during the Laschamps geomagnetic excursion was up to twice as large as previously estimated. Moreover, our results indicate that an accurate evaluation of ocean circulation models by means of radiocarbon requires to consider transient climate-radiocarbon simulations over millennia rather than centuries.
Apareció: jueves, 24 de septiembre. Communications Earth & Environment. Revista con revisión por pares.