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首页> 外文期刊>Journal of marine systems: journal of the European Association of Marine Sciences and Techniques >Evolution and fluxes of ~(137)Cs in the Black Sea/Turkish Straits System/North Aegean Sea
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Evolution and fluxes of ~(137)Cs in the Black Sea/Turkish Straits System/North Aegean Sea

机译：黑海/土耳其海峡系统/北爱琴海中〜（137）Cs的演化和通量

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摘要

The vertical profiles of ~(137)Cs were determined in the North Aegean, Marmara and Black Seas, to assess inventories and fluxes of the radionuclide in these basins. The inventory of ~(137)Cs in the Western Black Sea integrated from the surface down to 400 m water depth is 3.4 ± 0.1 kBq m~(?2), which is surprisingly close to the amount determined in 1988, decay corrected to 2007 (2.9 ± 0.1 kBq m~(?2)). On the other hand, based on the comparison of profiles roughly 20 years apart, it is estimated that about 1 kBq m~(?2) has been transferred from above the halocline to depths below the halocline, emphasizing the effective redistribution of tracers within the same period. We estimate that about 12 TBq y~(?1) of ~(137)Cs presently leaves the Black Sea with the upper layer flow through the Bosphorus and only 2 TBq y~(?1) is returned with the lower layer inflow of Mediterranean water from the Marmara Sea. Accounting for river fluxes, estimated on the order of 2 TBq y~(?1) few years after the Chernobyl accident, and possibly decreased by now, we can thus estimate a net rate of loss of about 8–10 TBq y~(?1). Investigating the effective redistribution in the upper water column, the supply by the inflowing Mediterranean water alone does not explain the increase of ~(137)Cs concentration and inventory at intermediate depths in the Western Black Sea. The most important mechanism transferring ~(137)Cs and dissolved contaminants from the surface water to the sub-pycnocline layer appears to be the turbulent entrainment of a larger quantity of Black Sea water into the inflowing plume of Mediterranean water through mixing processes on the southwestern shelf and continental slope following its exit from the Bosphorus. This process produces an extra export of some10 TBq y~(?1) of ~(137)Cs from the surface to the sub-pycnocline depths of the Black Sea, a quantity comparable in magnitude to the total export out from the basin. It is the entrainment flux resulting from the mixing, and the further advection and penetration of this water into the Black Sea deeper layer (200–600 m) that seems to maintain the inventory with little change over time. Through these two processes the Black Sea surface layer (0–50 m) loses every year about 4% of its total inventory of ~(137)Cs.
机译：在北爱琴海，马尔马拉和黑海确定了〜（137）Cs的垂直剖面，以评估这些盆地中放射性核素的清单和通量。从表层到水深达400 m处的西黑海〜（137）Cs总量为3.4±0.1 kBq m〜（？2），出乎意料地接近1988年确定的量，衰减至2007年校正（2.9±0.1 kBq m〜（？2））。另一方面，根据相隔大约20年的剖面的比较，估计大约1 kBq m〜（？2）已从盐湖线上方转移到盐湖线以下的深度，强调了示踪剂在有效范围内的重新分布。同一时期。我们估计，目前约（137）Cs的约12 TBq y〜（？1）离开黑海，上层流经博斯普鲁斯海峡，只有2 TBq y〜（？1）返回地中海，下层流入地中海。来自马尔马拉海的水。考虑到河流量，切尔诺贝利事故发生后几年估计约为2 TBq y〜（？1），并且现在可能会减少，因此，我们可以估算出约8–10 TBq y〜（？）的净损失率。 1）。调查上部水柱中的有效再分配，仅地中海流入的水供应不能解释〜（137）Cs浓度的增加和西黑海中间深度的库存。将〜（137）Cs和溶解的污染物从地表水转移到比浓菌碱层的最重要机制似乎是通过西南地区的混合过程将大量黑海水湍急地夹带到流入的地中海水羽流中从博斯普鲁斯海峡退出后的大陆架和大陆坡。该过程从地表到黑海的亚次青霉素深处产生了约10 TBq y〜（？1）〜（137）Cs的额外出口，其数量在数量上可与盆地的总出口相媲美。混合产生的夹带通量，以及该水进一步平流和渗透到黑海深层（200–600 m）中，似乎保持了库存随时间的变化很小。通过这两个过程，黑海表层（0–50 m）每年损失约（137）Cs总存量的4％。

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