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sampling strategy
permits an accuracy of 0.003 S with proper standardization. The high temperature coefficient of electrical conductivity of seawater (3 %) demands
either a very good and stable temperature compensation or a measurement
in a thermostat of high, long-term stability (better than 1 mK). This last
principle is applied in modern four-electrode flow-through salinometers
which have a 0.001 S precision.
salps ~ Thaliacea.
salt marsh (syn. tidal marsh) tidal flat regularly or intermittently flooded by the
tide, fringes the intertidal zone of muddy and sandy coasts of estuaries and
protected shores in temperate and cold latitudes. Only a few plants have
acquired the necessary salt tolerance to grow here. A succession of species
occurs in zones from low to high, such zonation being mainly related to the
height of the marsh relative to the average water level. Most of the typical
genera occur worldwide: Salicornia, Spartina, Suaeda, Limonium, Scirpus,
Juncus. The lower limit lies at about mid-tide level for the US east coast, but
higher (round neap high-tide level) for European coasts. The upper limit is
generally controlled by the level reached by spring tides. In the tropics similar areas may be covered by shrubs and trees and is then called mangrove
swamp or man gal.
salt wedge when freshwater and seawater meet, as is the case in estuaries, the two
water masses with different densities do not in all cases mix completely,
depending on the available mixing energy from wind, tide, and current.
When the two water masses can be recognized in the mixing zone by their
density (salinity) difference, the inward flowing tongue of seawater is
referred to as salt wedge.
sampling strategy especially in marine sciences, describing the physical, chemical, and biological nature of the oceans, and studying the processes in the
marine system, the subject is far too large to allow any other approach than
to study relatively minute samples taken from the whole. Even the collection
of a relatively small number of such samples, be it pieces of seabed, volumes
of water, number of organisms, or automatic registration of some characteristic somewhere over some time period (which is also a sample), involves
expensive operations including the use of specially equipped research vessels. Hence, special attention is given to the details of sampling: the choice of
proper sampling tools, positions, times, frequencies, etc. In general all aimed
at obtaining maximal appropriate information in return for the available
funds. The planning of optimal sampling strategies finds strong support in
statistics.
sampling strategy
permits an accuracy of 0.003 S with proper standardization. The high temperature coefficient of electrical conductivity of seawater (3 %) demands
either a very good and stable temperature compensation or a measurement
in a thermostat of high, long-term stability (better than 1 mK). This last
principle is applied in modern four-electrode flow-through salinometers
which have a 0.001 S precision.
salps ~ Thaliacea.
salt marsh (syn. tidal marsh) tidal flat regularly or intermittently flooded by the
tide, fringes the intertidal zone of muddy and sandy coasts of estuaries and
protected shores in temperate and cold latitudes. Only a few plants have
acquired the necessary salt tolerance to grow here. A succession of species
occurs in zones from low to high, such zonation being mainly related to the
height of the marsh relative to the average water level. Most of the typical
genera occur worldwide: Salicornia, Spartina, Suaeda, Limonium, Scirpus,
Juncus. The lower limit lies at about mid-tide level for the US east coast, but
higher (round neap high-tide level) for European coasts. The upper limit is
generally controlled by the level reached by spring tides. In the tropics similar areas may be covered by shrubs and trees and is then called mangrove
swamp or man gal.
salt wedge when freshwater and seawater meet, as is the case in estuaries, the two
water masses with different densities do not in all cases mix completely,
depending on the available mixing energy from wind, tide, and current.
When the two water masses can be recognized in the mixing zone by their
density (salinity) difference, the inward flowing tongue of seawater is
referred to as salt wedge.
sampling strategy especially in marine sciences, describing the physical, chemical, and biological nature of the oceans, and studying the processes in the
marine system, the subject is far too large to allow any other approach than
to study relatively minute samples taken from the whole. Even the collection
of a relatively small number of such samples, be it pieces of seabed, volumes
of water, number of organisms, or automatic registration of some characteristic somewhere over some time period (which is also a sample), involves
expensive operations including the use of specially equipped research vessels. Hence, special attention is given to the details of sampling: the choice of
proper sampling tools, positions, times, frequencies, etc. In general all aimed
at obtaining maximal appropriate information in return for the available
funds. The planning of optimal sampling strategies finds strong support in
statistics.