Physical Oceanography, Vol. 18, No. 5, 2008
ANALYSIS OF OBSERVATIONS AND METHODS FOR CALCULATING
HYDROPHYSICAL FIELDS IN THE OCEAN
INVESTIGATION OF THE BIOGEOCHEMISTRY OF METHANE AND
MECHANISMS OF ITS TRANSFER IN THE BLACK SEA
E. E. Sovga,
S. P. Lyubartseva,
and A. A. Lyubitsky
We demonstrate the importance of investigation of the behavior of methane as a source of energy
and an element of the Black-Sea ecosystem affecting the global behavior of the climate. We de-
scribe the genesis of methane and the processes of its aerobic and anaerobic oxidation. An espe-
cially important biogeochemical and ecological role is played by the anaerobic oxidation of
methane guaranteeing the formation of its effective sink inside the anaerobic zone and preventing
its penetration into the atmosphere as a greenhouse gas. On the basis of the analysis of the expe-
rimental data available from the literature, we also discuss the principal regularities of the distri-
bution of concentration of methane and its flows. It is shown that the formation of methane hy-
drates at the bottom in the abyssal part of the Black Sea and the events of jet gas release on the
periphery of the basin can be regarded as the components of a single global process of gas re-
lease from the bottom of the Black Sea. We present estimates of the components of methane
budget in the Black Sea. The results of simulation of the dynamics of methane bubbles and the
processes of their gas exchange with the medium are analyzed. The data of hydroacoustic mea-
surements are used to evaluate the distribution of methane bubbles in sizes and the mass transfer
of methane through the ocean–atmosphere interface. Finally, we consider the methods of math-
ematical simulation of the distribution of methane in the ecosystem of the Black Sea.
The analysis of the role of methane in the ecosystem of the Black Sea is a problem of primary importance
because methane is a source of energy. Since the water column of the Black Sea is anaerobic, the sea can be re-
garded as a gigantic reservoir of dissolved methane whose mass is estimated as
. As the main
sources of methane, we can mention the phenomenon of gas release in the shelf zone and bottom sediments of
the continental slope. As a potential source of energy, one can also consider large amounts of methane hydrates
accumulated in the bottom deposits in the abyssal part of the sea.
At present, the researchers give significant attention to the problems of biogeochemistry of methane in the
Black Sea in connection with the problem of global warming. Although the contribution of methane occupies
the second place among greenhouse gases after
the amount of thermal energy absorbed by methane per
unit mass is 21 times higher than for carbon dioxide. As shown in , the concentration of methane in the atmo-
sphere increases every year by
and, according to , 18% of methane is released by water basins. It is clear
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol, Ukraine.
Usikov Institute of Radiophysics and Electronics, Ukrainian Academy of Sciences, Kharkov, Ukraine.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
40–56, September–October, 2008. Original article submitted April 4,
272 0928-5105/08/1805–0272 © 2008 Springer Science+Business Media, Inc.