Dynamics of particles along the western margin of the Southern Adriatic: Processes involved in transferring particulate matter to the deep basin

摘要: ABSTRACT The Southern Adriatic is an area of dense shelf water (DSW) cascading and open-ocean convection. impact DSW events in transferring organic matter to the deep benthic community producing a wide range bedforms along continental margin has been highlighted recent years. In order improve our knowledge on interannual variability with ultimate goal understand timing formation transport as well process, its intensity duration, sea, March 2009 we deployed instrumented mooring field sediment waves (860 m depth) located down current Bari canyon. 2010, second was installed northern channel Winters 2009, 2010 2011 were mild particularly wet Po river discharge remained relatively high throughout whole winter. Hence, expected weak associated shallow overflowing off shelf. By contrast, winter 2012, North experienced severe cold wave NE Bora winds reduced fresh input. These weather conditions allowed extremely water. Three additional moorings quickly during this event Sea investigate spatial particle fluxes exiting from under influence strong event. Slow near-bottom currents, never exceeding 40 cm s − 1 , recorded between February 2012. Water temperatures depicted minor negative shifts. Total mass (TMFs) low (annual avg., 1.7–2.8 g m − 2  d 0.3–0.6 g m canyon field, respectively; peak values ≤ 6.8 g m ), but showed significant seasonal variability. Fluxes higher than those measured at deeper depth. Mass flux peaks 2112-DSW up 5 times previous years (up 18.70 g m mainly driven by localized pathways cascading. canyon, currents exceeded 70 cm s temperature dropped 12.2 °C while speeds also 1200 m depth (~ 60 cm s ) moat surrounding Dauno seamount. Surprisingly, occurred 16th 1st March, 3–4 weeks ahead usual occurrence, suggesting early arrival DSW. main process driving transfer across southern late winter–spring Mooring data NW–SE gradient kinetic energy upslope basin floor, indicating slope transverse flow modulated local obstruction caused rugged seafloor topography. one sites have possibility extend observations back time using continuous since published materials; approach evaluation mechanisms (e.g., convection, storm-driven downward transport, cascading) that are relevant when less vigorous processes sluggish. small amplitude total peaks, constant springs consistent enhanced vertical rain mid-water nepheloid layer, triggered turn not-particularly detaching reaches neutral buoyancy. Thus, (shallow vs. deep) plays first control particulate through western Adriatic, storm-induced can occasionally be too.