Interannual variation of settling particles that reflect upper-ocean
circulation in the southern Chukchi Borderland, 2010-2014
Abstract
Changes in the lower-trophic marine ecosystem and biogeochemical cycles
were considered with respect to the warming Arctic Ocean. The time
series monitoring of the hydrography and marine settling particles
supplies a large amount of information regarding the marine
lower-trophic ecosystem in with respect to the changing Arctic Ocean. To
investigate the interannual relationship between the settling particles
and hydrographic conditions of the western Arctic Ocean, bottom-tethered
sediment trap moorings were deployed at the Northwind Abyssal Plain
(NAP) and at the Chukchi Abyssal Plain from October 2010 to September
2014 to the east and west of the Chukchi Borderland. The settling
particles at both stations contained a significant amount of lithogenic
matter, with biogenic particles being a lateral advection of shelf
materials from shelf to basin. The many peaks of settling particle
fluxes at Station NAP in 2013–2014 corresponded to the hydrographic
events of passing oceanic eddies over the station, in addition to
seasonal biological production. Additionally, abundant gelatinous matter
was found in some summer samples. The settling flux data of particulate
organic matter and the mole ratio and stable isotope ratios of
particulate organic carbon and nitrogen in the settling particles
reflected the changes in the composition of trapped plankton assemblages
under various hydrographic conditions over the course of the four years
of the study.