7
algae
stances can be by different ways. Gases, fluid droplets, as well as particles
(sea salt, aerosols), can act as the physical state for exchange. The rate of
exchange is difficult to quantify but is largely dominated by the wind-driven mixing of the surface waters. At low wind velocity a very thin so-called
sea-surface microlayer may control the exchange rate. Gas exchange rates
can be assessed from vertical distributions of natural radioisotope 222Rn
(radon gas). Important for climatic conditions is the exchange of carbon dioxide.
Albatross Expeditions (1) (between 1867 and 1900) a US coastal survey ship that
under Louis Francois Comte de Pourtales and Louis Agassiz started dredging and sounding off Florida and between Florida and Cuba. Under direction of Alexander Agassiz (son of Louis A.), the Albatross carried out
oceanographical observations throughout the tropical Pacific in 1899-1900;
(2) (1947-1948) a Swedish round-the-world deep-sea expedition organized
by Hans Pettersson marks the start of seismic explorations (~seismic survey)
at sea under Waloddi Wiebull. The expedition used a piston corer invented by
Borje Kullenberg, which enabled for the first time taking deep-sea cores of
over 20 m length, studied by Gustaf Arrhenius, Eric Olausson et al. This gave
an enormous impetus to stratigraphic research (~stratigraphy) of recent deepsea sediments. Nils Jerlov dealt with optical measurements and currents.
albedo percentage of the incoming short-wave radiation that is reflected
(directly or diffusely) by a surface. For the sea surface the albedo strongly
depends on the angle of incidence of the radiation and the roughness of the
sea surface.
algae (Latin for seaweeds) non-taxonomical term to denote a large group of
autotrophic organisms that range in size from microscopic to several meters
long, and live in the sea, in freshwater, in moist surroundings on land, and
even inside other organisms (~symbiosis) . The algae comprise the autotrophic part of the prokaryotes (Monera): the Cyanobacteria (Cyanophyceae or
blue-green algae) and the autrotrophic part of the kingdom Protoctista. The
algae are separated into several phyla, subdivided into classes. This systematic grouping is done according to the pigments; unicellular and multicellular
classes can be found together in the same phylum. Next to the prokaryotic
Cyanobacteria, there are the eukaryotic phylum Rhodophyta with one single class
named the Rhodophyceae or red algae, the phyla Chrysophyta or golden-brown
algae, Xanthophyta or yellow-green algae, Bacillariophyta or diatoms, Phaeophyta or
brown algae, and the small (ten species) phylum Raphidophyta. Further there
are the phylum Prymnesiophyta comprising the coccolithophorids, the phylum
Eustigmatophyta (a small group newly separated from the Xanthophyta), the
phylum Cryptophyta, the Dinoflagellata, the phylum Euglenida, and finally the phylum Chlorophyta.
algae
stances can be by different ways. Gases, fluid droplets, as well as particles
(sea salt, aerosols), can act as the physical state for exchange. The rate of
exchange is difficult to quantify but is largely dominated by the wind-driven mixing of the surface waters. At low wind velocity a very thin so-called
sea-surface microlayer may control the exchange rate. Gas exchange rates
can be assessed from vertical distributions of natural radioisotope 222Rn
(radon gas). Important for climatic conditions is the exchange of carbon dioxide.
Albatross Expeditions (1) (between 1867 and 1900) a US coastal survey ship that
under Louis Francois Comte de Pourtales and Louis Agassiz started dredging and sounding off Florida and between Florida and Cuba. Under direction of Alexander Agassiz (son of Louis A.), the Albatross carried out
oceanographical observations throughout the tropical Pacific in 1899-1900;
(2) (1947-1948) a Swedish round-the-world deep-sea expedition organized
by Hans Pettersson marks the start of seismic explorations (~seismic survey)
at sea under Waloddi Wiebull. The expedition used a piston corer invented by
Borje Kullenberg, which enabled for the first time taking deep-sea cores of
over 20 m length, studied by Gustaf Arrhenius, Eric Olausson et al. This gave
an enormous impetus to stratigraphic research (~stratigraphy) of recent deepsea sediments. Nils Jerlov dealt with optical measurements and currents.
albedo percentage of the incoming short-wave radiation that is reflected
(directly or diffusely) by a surface. For the sea surface the albedo strongly
depends on the angle of incidence of the radiation and the roughness of the
sea surface.
algae (Latin for seaweeds) non-taxonomical term to denote a large group of
autotrophic organisms that range in size from microscopic to several meters
long, and live in the sea, in freshwater, in moist surroundings on land, and
even inside other organisms (~symbiosis) . The algae comprise the autotrophic part of the prokaryotes (Monera): the Cyanobacteria (Cyanophyceae or
blue-green algae) and the autrotrophic part of the kingdom Protoctista. The
algae are separated into several phyla, subdivided into classes. This systematic grouping is done according to the pigments; unicellular and multicellular
classes can be found together in the same phylum. Next to the prokaryotic
Cyanobacteria, there are the eukaryotic phylum Rhodophyta with one single class
named the Rhodophyceae or red algae, the phyla Chrysophyta or golden-brown
algae, Xanthophyta or yellow-green algae, Bacillariophyta or diatoms, Phaeophyta or
brown algae, and the small (ten species) phylum Raphidophyta. Further there
are the phylum Prymnesiophyta comprising the coccolithophorids, the phylum
Eustigmatophyta (a small group newly separated from the Xanthophyta), the
phylum Cryptophyta, the Dinoflagellata, the phylum Euglenida, and finally the phylum Chlorophyta.