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The carbon budget of the North Sea  [PDF]
H. Thomas,Y. Bozec,H. J. W. de Baar,K. Elkalay
Biogeosciences Discussions , 2004,
Abstract: A carbon budget has been established for the North Sea, a shelf sea of the NW European continental shelf. The air-sea exchange of CO2 has been assessed as closing term of the budget. The carbon exchange fluxes with the North Atlantic Ocean dominate the gross carbon budget. The net carbon budget – more relevant to the issue of the contribution of the coastal ocean to the marine carbon cycle – is dominated by the carbon inputs from rivers, the Baltic Sea and the atmosphere. The dominant carbon sink is the final export to the North Atlantic Ocean. The North Sea acts as a sink for organic carbon. More than 90% of the CO2 taken up from the atmosphere is exported to the North Atlantic Ocean making the North Sea a highly efficient continental shelf pump for carbon.
CO2 exchange in a temperate marginal sea of the Mediterranean Sea: processes and carbon budget
G. Cossarini,S. Querin,C. Solidoro
Biogeosciences Discussions , 2012, DOI: 10.5194/bgd-9-10331-2012
Abstract: Marginal seas play a potentially important role in the global carbon cycle; however, due to differences in the scales of variability and dynamics, marginal seas are seldom fully accounted for in global models or estimates. Specific high-resolution studies may elucidate the role of marginal seas and assist in the compilation of a complete global budget. In this study, we investigated the air-sea exchange and the carbon cycle dynamics in a marginal sub-basin of the Mediterranean Sea (the Adriatic Sea) by adopting a coupled transport-biogeochemical model of intermediate complexity including carbonate dynamics. The Adriatic Sea is a highly productive area owed to riverine fertilisation and is a site of intense dense water formation both on the northern continental shelf and in the southern sub-basin. Therefore, the study area may be an important site of CO2 sequestration in the Mediterranean Sea. The results of the model simulation show that the Adriatic Sea, as a whole, is a CO2 sink with a mean annual flux of 36 mg m 2 day 1. The northern part absorbs more carbon (68 mg m 2 day 1) due to an efficient continental shelf pump process, whereas the southern part behaves similar to an open ocean. Nonetheless, the Southern Adriatic Sea accumulates dense, southward-flowing, carbon-rich water produced on the northern shelf. During a warm year and despite an increase in aquatic primary productivity, the sequestration of atmospheric CO2 is reduced by approximately 15% due to alterations of the solubility pump and reduced dense water formation. The seasonal cycle of temperature and biological productivity modulates the efficiency of the carbon pump at the surface, whereas the intensity of winter cooling in the northern sub-basin leads to the export of C-rich dense water to the deep layer of the southern sub-basin and, subsequently, to the interior of the Mediterranean Sea.
The carbon budget of the North Sea
H. Thomas, Y. Bozec, H. J. W. de Baar, K. Elkalay, M. Frankignoulle, L.-S. Schiettecatte, G. Kattner,A. V. Borges
Biogeosciences (BG) & Discussions (BGD) , 2005,
Abstract: A carbon budget has been established for the North Sea, a shelf sea on the NW European continental shelf. The carbon exchange fluxes with the North Atlantic Ocean dominate the gross carbon budget. The net carbon budget – more relevant to the issue of the contribution of the coastal ocean to the marine carbon cycle – is dominated by the carbon inputs from rivers, the Baltic Sea and the atmosphere. The North Sea acts as a sink for organic carbon and thus can be characterised as a heterotrophic system. The dominant carbon sink is the final export to the North Atlantic Ocean. More than 90% of the CO2 taken up from the atmosphere is exported to the North Atlantic Ocean making the North Sea a highly efficient continental shelf pump for carbon.
Cavitation and bubble collapse in hot asymmetric nuclear matter  [PDF]
V. M. Kolomietz
Physics , 2004, DOI: 10.1103/PhysRevC.70.044321
Abstract: The dynamics of embryonic bubbles in overheated, viscous and non-Markovian nuclear matter is studied. It is shown that the memory and the Fermi surface distortions significantly affect the hinderance of bubble collapse and determine a characteristic oscillations of the bubble radius. These oscillations occur due to the additional elastic force induced by the memory integral.
Informally Employed Women: Their Characteristics and Contribution in Household Budget  [PDF]
Rana Ejaz Ali Khan,Tasnim Khan
Journal of Applied Sciences , 2007,
Abstract: The study highlights the contribution of working women (in the age group of 16-60 years) in their household budget. These women are involved in informal economy. Employing the OLS model on 1780 observations it is found that women as head of household, women=s education, ownership of assets by woman have positive effect on their contribution. Age of the woman has a non-linear effect. First the contribution increases and then decreases by increase in age of the woman. Married women contribute more to household budget.
The contribution of brown dwarfs to the local mass budget of the Galaxy  [PDF]
B. Fuchs,H. Jahreiss,C. Flynn
Physics , 1998,
Abstract: Based on the recent discoveries of free floating brown dwarfs we derive estimates of the local mass density of this population of objects. Mass density estimates from various surveys span the range 0.03 to 0.005 M_Sun/pc^3. These estimates are compared with the local mass densities of the other constituents of the galactic disk and, in particular, with the dynamically determined total local mass density. We argue that brown dwarfs might indeed contribute significantly to the local mass budget, but that a local mass density as high as 0.03 M_Sun/pc^3 as suggested by Ruiz et al. (1997) is rather unlikely.
Curvature Singularity in the Asymmetric Breakup of an Underwater Air Bubble  [PDF]
Lipeng Lai
Physics , 2012, DOI: 10.1063/1.4758280
Abstract: The presence of slight azimuthal asymmetry in the initial shape of an underwater bubble entirely alters the final breakup dynamics. Here I examine the influence of initial asymmetry on the final breakup by simulating the bubble surface evolution as a Hamiltonian evolution corresponding to an inviscid, two-dimensional, planar implosion. I find two types of breakups: a previously reported coalescence mode in which distant regions along the air-water surface curve inwards and eventually collide with finite speed, and a hitherto unknown cusp-like mode in which the surface develops sharp tips whose radii of curvature are much smaller than the average neck radius. I present three sets of results that characterize the nature of this cusp mode. First, I show that the cusp mode corresponds to a saddle-node. In other words, an evolution towards a cross-section shape with sharp tips invariably later evolves away from it. In phase space, this saddle-node separates coalescence modes whose coalescence planes lie along different spatial orientations. Second, I show that the formation of the sharp tips can be interpreted as a weakly first-order transition which becomes second-order, corresponding to the formation of a finite-time curvature singularity, in the limit that the initial perturbation amplitude approaches zero. Third I show that, as the curvature singularity is approached, the maximum surface curvature diverges approximately as $(t_c - t)^{-0.8}$, where $t_c$ is the onset time of the singularity and the maximum velocity diverges approximately as $(t_c-t)^{-0.4}$. In practice, these divergences imply that viscous drag and compressibility of the gas flow, two effects not included in my analysis, become significant as the interface evolves towards the curvature singularity.
The carbon budget of the Baltic Sea
K. Kuliński ,J. Pempkowiak
Biogeosciences (BG) & Discussions (BGD) , 2011,
Abstract: This paper presents the results of a comprehensive study of the Baltic Sea carbon budget. The Baltic Sea is very much influenced by terrestrial carbon input. Rivers are the largest carbon source, and their input amounts to 10.90 Tg C yr 1 (Tg = 1012 g) with a 37.5% contribution of organic carbon. On the other hand, carbon is effectively exported from the Baltic to the North Sea (7.67 Tg C yr 1) and is also buried in bottom sediments (2.73 Tg C yr 1). The other sources and sinks of carbon are of minor importance. The net CO2 emission (1.05 Tg C yr 1) from the Baltic to the atmosphere was calculated as the closing term of the carbon budget presented here. There is a net loss of organic carbon, which indicates that the Baltic Sea is heterotrophic.
The carbon budget of the Baltic Sea  [PDF]
K. Kuliński,J. Pempkowiak
Biogeosciences Discussions , 2011, DOI: 10.5194/bgd-8-4841-2011
Abstract: The paper presents the results of a detailed study of the Baltic Sea's carbon budget. The Baltic is very much influenced by terrestrial carbon input. Import from the land from rivers is the largest carbon source, amounting to 10.90 Tg C yr 1 with a 37.5 % contribution from organic carbon. On the other hand, carbon is effectively exported from the Baltic to the North Sea (7.67 Tg C yr 1) and is also buried in bottom sediments (2.73 Tg C yr 1). The other sources and sinks of carbon are of minor importance. The net CO2 emission (1.05 Tg C yr 1) from the Baltic to the atmosphere was calculated as the closing term of the carbon budget presented here. There is a net loss of organic carbon, which indicates that the Baltic Sea is heterotrophic.
Asymmetric bubble disconnection: persistent vibration evolves into smooth contact  [PDF]
Konstantin S. Turitsyn,Lipeng Lai,Wendy W. Zhang
Physics , 2009, DOI: 10.1103/PhysRevLett.103.124501
Abstract: Focusing a finite amount of energy dynamically into a vanishingly small amount of material requires that the initial condition be perfectly symmetric. In reality, imperfections are always present and cut-off the approach towards the focusing singularity. The disconnection of an underwater bubble provides a simple example of this process. An initial asymmetry in the shape of the bubble neck excites vibrations that persist over time. Often the vibrations evolve into a smooth contact that severs the neck into several lobes.
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