Publication Date:
2017-06-28
Description:
We explore a novel and spatially extensive dataset obtained from Biogeochemical-Argo (or BGC-Argo) floats, containing 16,796 profiles of the particulate backscattering coefficient at 700nm ( b b p (700)) measured with three different sensors. We focus at the 900-950m depth interval (within the mesopelagic), where we blackfound values to be relatively constant. While we find significant differences between estimates of b b p (700) obtained with different sensors (≈30 % disagreement), the median values in most oceanic regions obtained with blacka single type of sensor are within 50 % of each other and are consistent with measurements of suspended mass conducted in the early 1970's. Deviations from the quasi-constant background value likely indicate times and locations associated with higher particulate export to depth. Indeed, we observe that in productive high latitude regions, a deep seasonal signal is observed, with enhanced values recorded blacka few months after surface spring/summer maximal concentrations. In addition, the deep b b p (700) is highest in regions exhibiting suboxic-anoxic conditions (e.g. Northern Indian Ocean), which have been associated with local particulate production as well as reduced particle flux attenuation.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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