Elaboration and application of an algorithm to detect the cascading near the Severnaya Zemlya Archipelago coast
Abstract
The article discusses possible processing of data from a mathematical model, which allows identification of areas where cascading is observed. Cascading is a bottom gravity current along and across the bottom topography slopes, that transports denser water formed in the coastal and shelf areas of seas and oceans. The NEMO model calculation for the period 1986–2010 is used as an initial data set for the Severnaya Zemlya Archipelago area with the time resolution of 5 days and the spatial resolution of 1/10°. The choice of the area is due to the availability of hydrological data indicating the occurrence of cascading during 1984 and 1985 expeditions.
The suggested algorithm makes it possible to identify the areas of cascading occurrence, namely three cases in December 1991 and 1993, and December 2004 – January 2005 near the Maly Taimyr Island. The case of cascading in December 1991 was analyzed. The comparison of water densities at the bottom and overlying horizons for the neighboring grid nodes during four consecutive 5-day periods (December 12–31) revealed the transition of stable density stratification of waters to the stratification characteristic of cascading. During the third 5-day period dense waters formed in the nodes with shallow depth (16 m) flow down the slope to a depth of 66 m. The density of water increases as a result of salinization during ice formation in shallow waters near the Maly Taimyr Island. Thus, the depth difference of cascading was 50 m. During the fourth 5-day period after cascading, the density structure becomes stable again. It was found that the 5-day time interval of the model data array applied for the study is sufficient to reveal the cascading process.
Supporting agencies: The development of the algorithm was financially supported by the Russian Foundation for Basic Research (grant no. 19-35-90124 "PHD – students").
About the Author
F. K. Tuzov
Lomonosov Moscow State University, Faculty of Geography; All-Russian Research Institute for Civil Defense and Emergencies
Russian Federation
Russian Federation
Department of Oceanology, postgraduate student; research fellow
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For citations:
Tuzov F.K. Elaboration and application of an algorithm to detect the cascading near the Severnaya Zemlya Archipelago coast. Vestnik Moskovskogo universiteta. Seriya 5, Geografiya. 2021;(4):52-61. (In Russ.)
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