f-ratio
132
rents flow not in the direction of the wind, but at an angle (in the northern
hemisphere to the right). This enabled Vagn Walfrid Ekman to develop his
theory on wind-driven currents and the deflecting force of the earth's rotation (~Coriolis force). As a result of this expedition, Fridtjof Nansen and Bjorn
Helland-Hansen tried to improve accuracy of the measurements of salinity
and temperature, resulting in Nansen's reversing water bottles and reversing
thermometers for serial measurements at oceanographic stations. The Fram
also made the first gravity measurements at sea during its ice drift; later
such measurements were expanded much by Vening Meinesz during his
Pendulum Expeditions (~Vening Meinesz' Submarine Pendulum Surveys).
f-ratio ~new production.
free-air anomaly ~gravity anomaly.
free wave a wave that has been generated outside the area of occurrence or at an
earlier time, and that, time and area considered, is independent of the presence
of a local external forcing: this in contrast to a forced wave. Energy input into the
wave only occurs by an energy flux across the boundary of the definition area.
freshwater natural water, derived from rain or melted snow, with low concentration of dissolved minerals. The chemical composition may be highly
variable, in contrast to seawater, in which the concentration ratios of the
major solutes are stable.
Freundlich and Langmuir isotherms for sorption-desorption processes, partition
can be described, otherwise than by distribution coefficients, by either the
Freundlich or Langmuir isotherm. They are, however, only applicable in systems of reduced complexity, where the Freundlich isotherm has an empirical
basis and the Langmuir isotherm is considered to have a thermo-dynamic
background. The Freundlich isotherm is given by Cad, = K C,o/lIn, K and n
being constants; the Langmuir relation is given by: Cad, = Kj C,o/(l +K 2 C,o/)' Kj
and K2 also being constants. At dilute conditions both relations allow for an
almost linear representation when Cad, is plotted against C,ol' thus approaching proportionality between these concentrations with the distribution coefficient
Kd as a constant factor.
friction is the process by which large-scale motions are transformed into heat.
In the case of a current flowing over a bottom friction is caused by the turbulent transport of momentum towards the bottom. This gives a bottom
stress opposed to the current direction, which depends quadratically on the
current speed. The roughness of the bottom is another important factor in
bottom friction, and its effect is represented by a so-called drag coefficient. For
some problems, somewhat artificially, a linear relation between current
132
rents flow not in the direction of the wind, but at an angle (in the northern
hemisphere to the right). This enabled Vagn Walfrid Ekman to develop his
theory on wind-driven currents and the deflecting force of the earth's rotation (~Coriolis force). As a result of this expedition, Fridtjof Nansen and Bjorn
Helland-Hansen tried to improve accuracy of the measurements of salinity
and temperature, resulting in Nansen's reversing water bottles and reversing
thermometers for serial measurements at oceanographic stations. The Fram
also made the first gravity measurements at sea during its ice drift; later
such measurements were expanded much by Vening Meinesz during his
Pendulum Expeditions (~Vening Meinesz' Submarine Pendulum Surveys).
f-ratio ~new production.
free-air anomaly ~gravity anomaly.
free wave a wave that has been generated outside the area of occurrence or at an
earlier time, and that, time and area considered, is independent of the presence
of a local external forcing: this in contrast to a forced wave. Energy input into the
wave only occurs by an energy flux across the boundary of the definition area.
freshwater natural water, derived from rain or melted snow, with low concentration of dissolved minerals. The chemical composition may be highly
variable, in contrast to seawater, in which the concentration ratios of the
major solutes are stable.
Freundlich and Langmuir isotherms for sorption-desorption processes, partition
can be described, otherwise than by distribution coefficients, by either the
Freundlich or Langmuir isotherm. They are, however, only applicable in systems of reduced complexity, where the Freundlich isotherm has an empirical
basis and the Langmuir isotherm is considered to have a thermo-dynamic
background. The Freundlich isotherm is given by Cad, = K C,o/lIn, K and n
being constants; the Langmuir relation is given by: Cad, = Kj C,o/(l +K 2 C,o/)' Kj
and K2 also being constants. At dilute conditions both relations allow for an
almost linear representation when Cad, is plotted against C,ol' thus approaching proportionality between these concentrations with the distribution coefficient
Kd as a constant factor.
friction is the process by which large-scale motions are transformed into heat.
In the case of a current flowing over a bottom friction is caused by the turbulent transport of momentum towards the bottom. This gives a bottom
stress opposed to the current direction, which depends quadratically on the
current speed. The roughness of the bottom is another important factor in
bottom friction, and its effect is represented by a so-called drag coefficient. For
some problems, somewhat artificially, a linear relation between current