Simulation of annual plankton productivity cycle in the Black Sea by a one-dimensional physical-biological model

Oğuz, Temel
Ducklow, H
MalanotteRizzoli, P
Tuğrul, Süleyman
Nezlin, NP
Ünlüata, Ü
The annual cycle of the plankton dynamics in the central Black Sea is studied by a one-dimensional vertically resolved physical-biological upper ocean model, coupled with the Mellor-Yamada level 2.5 turbulence closure scheme. The biological model involves interactions between the inorganic nitrogen (nitrate, ammonium), phytoplankton and herbivorous zooplankton biomasses, and detritus. Given a knowledge of physical forcing, the model simulates main observed seasonal and vertical characteristic features, in particular, formation of the cold intermediate water mass and yearly evolution of the upper layer stratification, the annual cycle of production with the fall and the spring blooms, and the subsurface phytoplankton maximum layer in summer, as well as realistic patterns of particulate organic carbon and nitrogen. The computed seasonal cycles of the chlorophyll and primary production distributions over the euphotic layer compare reasonably well with the data. Initiation of the spring bloom is shown to be critically dependent on the water column stability. It commences as soon as the convective mixing process weakens and before the seasonal stratification of surface waters begins to develop. It is followed by a weaker phytoplankton production at the time of establishment of the seasonal thermocline in April. While summer nutrient concentrations in the mixed layer are low enough to limit production, the layer between the thermocline and the base of the euphotic zone provides sufficient light and nutrient to support subsurface phytoplankton development. The autumn bloom takes place some time between October and December depending on environmental conditions. In the case of weaker grazing pressure to control the growth rate, the autumn bloom shifts to December-January and emerges as the winter bloom or, in some cases, is connected with the spring bloom to form one unified continuous bloom structure during the January-March period. These bloom structures are similar to the year-to-year variabilities present in the data.


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This paper examines monthly variability of climatological mean sea surface temperature (SST) in the Black Sea. A total of eight products, including observation-and model-based SST climatologies, are formed and compared with each other. Some of the observation-based SST data sets include only satellite measurements, while others combine in situ temperatures, such as those from moored and drifter buoys, with satellite data. Climatologies for numerical weather prediction (NWP) model-based data sets are formed ...
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Yalçıner, Ahmet Cevdet; Talipova, T; Kurkin, A; Kozelkov, A; Zaitsev, A (American Geophysical Union (AGU), 2004-12-15)
The tsunami hazard in the Black Sea is discussed by comparing historical, instrumental data and numerical results. There are 22 tsunami events in the Black Sea documented since the first century, and nine of them have occurred in twentieth century. The numerical simulations of tsunami propagation for the 1966 and 1939 events are performed by using the framework of the shallow-water theory. The instrumental data from tide gauge records are used to compare and validate the simulation results and estimate the ...
Citation Formats
T. Oğuz, H. Ducklow, P. MalanotteRizzoli, S. Tuğrul, N. Nezlin, and Ü. Ünlüata, “Simulation of annual plankton productivity cycle in the Black Sea by a one-dimensional physical-biological model,” JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, pp. 16585–16599, 1996, Accessed: 00, 2020. [Online]. Available: