Depth attenuation of organic matter export associated with jelly falls

• DOI: 10.4319/lo.2011.56.5.1917
• Publication Date: 2011-09-06T19:19:03Z
• Authors: Mario Lebrato; Markus Pahlow; Andreas Oschlies; Kylie A. Pitt; Daniel O. B. Jones; Juan Carlos Molinero; Robert H. Condon
• Keywords: 13. Climate action; 14. Life underwater; 551; 01 natural sciences; 0105 earth and related environmental sciences

We explore the attenuation in the export ratio of jelly‐POM (particulate organic matter) with depth as a function of the decay rate, temperature, and sedimentation rate. Using data from the Vertical Transport In the Global Ocean project, we compare ratios computed with the Martin‐curve, with a particle‐based parameterization, and with sediment‐trap data. Owing to the temperature dependence of the decay rate (Q10 = 4.28), the jelly‐POM export ratio below 500 m is 20–45% larger in subpolar and temperate areas than in the tropics. Vertical migration of gelatinous zooplankton leads to a variable starting depth of a jelly fall (death depth), which governs the start of remineralization, and the fate of the biomass. Owing to the absence of observations, we employ a sinking speed matrix ranging from 100 m d‐1 to 1500 m d‐1 to represent slow‐ and fast‐sinking carcasses. The assumption of a constant decay rate k independent of temperature in other particle‐based models may not be appropriate. These results provide information for including jelly‐POM in global biogeochemical model formulations.