On the barium–oxygen consumption relationship in the Mediterranean Sea: implications for mesopelagic marine snow remineralization

[摘要] In the ocean, remineralization rate associated with sinking particles is a crucial variable. Since the 1990s, particulate biogenic barium ( Ba xs ) has been used as an indicator of carbon remineralization by applying a transfer function relating Ba xs to  O 2 consumption (Dehairs's transfer function, Southern Ocean-based). Here, we tested its validity in the Mediterranean Sea (ANTARES/EMSO-LO) for the first time by investigating connections between Ba xs , prokaryotic heterotrophic production (PHP) and oxygen consumption ( JO 2 -Opt; optodes measurement). We show that (1) higher Ba xs (409 pM; 100–500 m) occurs in situations where integrated PHP (PHP 100 / 500 = 0.90 ) is located deeper, (2) higher Ba xs occurs with increasing JO 2 -Opt, and (3) there is similar magnitude between JO 2 -Opt (3.14 mmol m −2  d −1 ; 175–450 m) and JO 2 -Ba (4.59 mmol m −2  d −1 ; transfer function). Overall, Ba xs , PHP and JO 2 relationships follow trends observed earlier in the Southern Ocean. We conclude that such a transfer function could apply in the Mediterranean Sea.

[学科分类] 大气科学