Application of chemical tracers to an estimate of benthic denitrification in the Okhotsk Sea

To estimate benthic denitrification in a marginal sea, we assessed the usefulness of , a new tracer to measure the excess nitrogen gas (N-2) using dissolved N-2 and argon (Ar) with N* in the intermediate layer (26.6-27.4 sigma (theta) ) of the Okhotsk Sea. The examined parameters capable of affecting are denitrification, air injection and rapid cooling. We investigated the relative proportions of these effects on using multiple linear regression analysis. The best model included two examined parameters of denitrification and air injection based on the Akaike information criterion as a measure of the model fit to data. More than 80 % of was derived from the denitrification, followed by air injection. Denitrification over the Okhotsk Sea shelf region was estimated to be 5.6 +/- A 2.4 mu mol kg(-1). The distribution of was correlated with potential temperature (theta) between 26.6 and 27.4 sigma (theta) (r = -0.55). Therefore, we concluded that and N* can act complementarily as a quasi-conservative tracer of benthic denitrification in the Okhotsk Sea. Our findings suggest that in combination with N* is a useful chemical tracer to estimate benthic denitrification in a marginal sea.