Cross-shelf exchange in the northwestern Black Sea

Abstract

The transports of water, heat, and salt between the northwestern shelf and deep interior of the Black Sea are investigated using a high-resolution three-dimensional primitive equation model. From April to August 2005, both onshore and offshore cross-shelf break transports in the top 20 m were 0.24 Sv on average, which is equivalent to the replacement of 60% of the volume of surface shelf waters (0-20 m) per month. Two main exchange mechanisms are studied: Ekman transport, and transport by mesoscale eddies and associated meanders of the Rim Current. The Ekman drift causes nearly uniform onshore or offshore flow over a large section of the shelf break, but it is confined to the upper layers. In contrast, eddies and meanders penetrate deep down to the bottom, but they are restricted laterally. During the strong wind events of 15-22 April and 1-4 July, some 0.66 3 10 12 and 0.44 3 10 12 m 3 of water were removed from the northwestern shelf, respectively. In comparison, the single long-lived Sevastopol Eddy generated a much larger offshore transfer of 2.84 3 10 12 m 3 over the period 23 April to 30 June, which is equivalent to 102% of the volume of northwestern shelf waters. Over the study period, salt exchanges increased the average density of the shelf waters by 0.67 kg m 23 and reduced the density contrast between the shelf and deep sea, while lateral heat exchanges reduced the density of the shelf waters by 0.16 kg m 23 and sharpened the shelf break front.

Cross‐shelf exchange in the shelf of the East China Sea

“…On the other hand, the Ekman drift is larger than that in the northwestern Black Sea shelf break as seen by Zhou et al . [], which focused on the cross‐shelf break exchange in the warm seasons when wind forcing was relatively weak.…”

“…[] and Zhou et al . []. The hindcast run was driven by meteorological forcing and boundary conditions for 2006.…”

Cross‐shelf water exchange in the East China Sea as estimated by satellite altimetry and in situ hydrographic measurement

“…Furthermore, the way of the decomposition of the CST into three dynamic components can be applied to other shelves. In particular, for the surface and bottom Ekman transports [Zhou et al, 2014]. However, the application of the much larger on-shelf and off-shelf components than the net transport should be careful, because it is related to the inertia of strong Kuroshio Current and specific bathymetry change northeast of Taiwan.…”

Features of the Oxygen and Hydrogen Sulfide Vertical Distribution in the Black Sea Based on the Expedition Data Obtained by the Marine Hydrophysical Institute in 1995–2015

“…Вероятнее всего, отмеченное поднятие изосульфид в шкале плотностей представляет собой сезонное явление, поскольку в этом же районе летом 2011 г. изосульфида 3 мкМ располагалась ниже изопикны σt = 16,0 кг/м 3 , а осенью 2010 г. чуть ниже изопикны σt = 16,1 кг/м 3 , то есть наблюдается постепенное заглубление изосульфиды 3 мкМ при переходе от весеннего периода к осеннему. Нельзя, однако, исключить влияние динамики вод, например различных фаз развития Севастопольского антициклона [19][20][21], на положение верхней границы сероводородной зоны в этом районе.…”