ISS
hydrostatic approximation
ered a continuum: the interaction between the molecules is not taken explicitly into account, but implicitly by the introduction of physical properties
like viscosity or surface tension. In principle, hydrodynamics is based upon
three equations: the equation of motion, in which the combined effect of all
forces acting on elements of the fluid is considered, the continuity equation in
which the condition is formulated that the total mass is conserved and the
equation of state, relating mass and volume. The most elementary expression of
the equation of motion is that of the Navier-Stokes equation. For practical problems simplified equations are often used.
hydrogen-ion or proton (H+). These do not exist as such in aqueous solutions,
but are associated with water molecules to hydronium ions (H 3 0+). The negative logarithm of its concentration is called pH.
hydrogen sulfide a very poisonous gas. It is an intermediary of the microbial sulfur cycle. In aquatic systems it is in a pH -dependent equilibrium with its dissociated forms: H z 5 = H5- + H+ = 5 z - + 2H+.
hydrography stands for two types of description of the seas. In the first place it
is used for the charting of the seas, with depths and coastlines etc., primarily for use in navigation, and can be considered marine cartography.
However, usually the collection and distribution of other navigational information, including tides and currents, also fall under hydrography in this
sense. In the second place it stands for "descriptive oceanography" and is
mainly concerned with the description of water properties, their distribution and variations.
hydrological cycle the cycle of water around the globe with the ocean as the
largest reservoir with 1.4 10 6 km 3 of water, in which its residence time is
44000 years. Locally, hydrological cycles indicate the cycle of precipitation,
evaporation, inflow, and outflow of water.
hydrolysis chemical reaction in which HzO is added to the original molecule.
Due to hydrolysis organic polymers such as polysaccharides, proteins and
lipids are split into their basic units. In the hydrolysis of metal compounds
and ions polynuclear hydroxo-complexes are formed that largely determine
the behavior of these metals in seawater.
hydromedusa ~Hydrozoa.
hydrostatic approximation approximation of vertical component of the equations
of motion in hydrodynamics, assuming no vertical motion. The pressure distribution in the ocean is derived from the hydrostatic equations derived from
this approximation.
hydrostatic approximation
ered a continuum: the interaction between the molecules is not taken explicitly into account, but implicitly by the introduction of physical properties
like viscosity or surface tension. In principle, hydrodynamics is based upon
three equations: the equation of motion, in which the combined effect of all
forces acting on elements of the fluid is considered, the continuity equation in
which the condition is formulated that the total mass is conserved and the
equation of state, relating mass and volume. The most elementary expression of
the equation of motion is that of the Navier-Stokes equation. For practical problems simplified equations are often used.
hydrogen-ion or proton (H+). These do not exist as such in aqueous solutions,
but are associated with water molecules to hydronium ions (H 3 0+). The negative logarithm of its concentration is called pH.
hydrogen sulfide a very poisonous gas. It is an intermediary of the microbial sulfur cycle. In aquatic systems it is in a pH -dependent equilibrium with its dissociated forms: H z 5 = H5- + H+ = 5 z - + 2H+.
hydrography stands for two types of description of the seas. In the first place it
is used for the charting of the seas, with depths and coastlines etc., primarily for use in navigation, and can be considered marine cartography.
However, usually the collection and distribution of other navigational information, including tides and currents, also fall under hydrography in this
sense. In the second place it stands for "descriptive oceanography" and is
mainly concerned with the description of water properties, their distribution and variations.
hydrological cycle the cycle of water around the globe with the ocean as the
largest reservoir with 1.4 10 6 km 3 of water, in which its residence time is
44000 years. Locally, hydrological cycles indicate the cycle of precipitation,
evaporation, inflow, and outflow of water.
hydrolysis chemical reaction in which HzO is added to the original molecule.
Due to hydrolysis organic polymers such as polysaccharides, proteins and
lipids are split into their basic units. In the hydrolysis of metal compounds
and ions polynuclear hydroxo-complexes are formed that largely determine
the behavior of these metals in seawater.
hydromedusa ~Hydrozoa.
hydrostatic approximation approximation of vertical component of the equations
of motion in hydrodynamics, assuming no vertical motion. The pressure distribution in the ocean is derived from the hydrostatic equations derived from
this approximation.