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I Sli
fra Atlanterhavet, men staar i aaben Forbindelse med
det indre Ishav. I Færø-Shetland Renden cirkulerer
iskoldt Vand, saaledes som Pilene antyde. Ildenfor Norges
Vestkyst bringer den nordgaaende og opstigende Bevægelse
Vand af — 1° Temperatur op langs Banken (Pl. XXI).
Omkring den r<0. Breddegrad gaar det varme Vand
vestover og nedover, idet det følger Draget fra de dybere
Lags bariske Maximum. I Sydvest for Beeren-Eiland, hvor
det bariske Minimum støder op til Banken, lofter ogsaa
koldt Vand fra Dybet sig op. Langs denne Banke og
Spidsbergbanken gaar, i Overensstemmelse med
Isobarernes Retning, en varm Tunge nordover. Lige ved Banken
suger Bevægelsen dog noget koldere Vand op langs denne.
I Polarstrømmen gjenfinde vi de samme Hovedtræk i
Temperaturen som i de højere liggende Lag. I Station No. 52
yttrer Dybets bariske Maximum sig ved den noget højere
Temperatur i Modsa;tning til No. 51 og No. 53.
Strømmens Hastighed i 500 Favnes Dyb er
gjennemgaaende lidt mindre end i 300 Favne. F. Ex. ved Jan
Mayen 0.09 in. p. S. (4 Kvm. i 24h). Udenfor Norge
tindes den samme Hastighed.
I 1000 Favnes Dyb er Trykkets Fordeling (Pl. XLVI)
en ganske anden end i de højere Lag. Istedetfor et
centralt Minimum have vi flere Minima og flere Maxima.
Som ovenfor paapeget. komme de vertieale Bevægelser her
til at gjøre sig mere gjældende end i de højere Lag.
I Norskedybet læner et barisk Maximum sig til den
sydlige Rand af dette. Den deraf flydende nedadstigende
Bevægelse giver (Pl. XXIII) et Temperatur-Maximum.
Man vil bemerke, at i dette Bækken pege Gradienterne
mod Nord. Men de ere sterkere paa Østsiden end paa
Vestsiden. Den horizontale Bevægelse maa derfor adlyde
de første og blive nordgaaende paa Østsiden, sydgaaende
paa Vestsiden, østgaaende paa Sydsiden. Paa Vestsiden,
hvor Bevægelsen gaar mod Gradienten, vil den blive
nedstigende. Saavel PI. XXIII som Pl. XXV viser, at det
er det kolde Vand fra Jan Mayen Renden, som her søger
nedover langs Bunden. Paa Østsiden gaar Bevægelsen med
Gradienten, kanske med Acceleration, og med Opstigning
mod Trykkets Minimum i G8° Bredde. En sterk
Opsugning fra neden af koldt Vand er Følgen, og samtidig
dermed en Sugning af Vand langs Bækkenets Sydrand.
Virkningen her er dog svagere, da Trykkets Maximum tvinger
de højere Lag her nedad, og da Vandet i Dybet maa
afgives for en Del til: Færø-Shetland-Renden. Den fulde
Virkning af Maxiniuinstrvkket kommer imidlertid først
tilsyne midt i Bækkenet, hvor Isothermen for —1°
(Tversnit X, Pl. X. Station No. 52 og PI. XXVI) naar ned
til en betydelig Dybde.
Paa (»7° til 68° Bredde kan det kolde Vand fra Jan
The North Ocean is entirely cut off from the Atlantic,
but in open connection with the inner tracts of the Polar
Sea. In the Færoc-Shetland Channel, ice-cold water
circulates. as indicated by the arrows. Off the West Coast
of Norway, the northward-setting and ascending motion
brings up water of 1° temperature along the bank i PI.
XXI). At the 70th parallel of latitude, the warm water
passes west and downward, following, as it does so, the
suction from the baric maximum of the deeper strata.
South-west of Beeren-Eiland, where the baric minimum
reaches the bank, cold water rises up from the deep.
Along this bank and that of Spitsbergen, extends, in
conformity with the direction of the isobars, a warm tongue
northward. In immediate proximity to the bank, however, the
motion draws up along it somewhat colder water. In the
Polar current, as regards temperature, we observe the same
principal features as in the higher-lying strata. At
Station No. 52. the baric maximum of the deep asserts its
influence in the somewhat higher temperature, as opposed
to No. 51 and No. 53.
The velocity of the current at a depth of 500 fathoms
is somewhat less on the whole than at a depth of 300
fathoms: for example, off Jan Mayen 0.09 m. per see. i4
naut. miles in 24 hours). Ofl the coast of Norway, the
same velocity is met with.
At a depth of 1000 fathoms, the distribution of pressure
(PI. XLVI) is totally different from that in the higher
strata. Instead of a central minimum, we have several
minima and several maxima. As pointed out above, the
vertical motions here will be more prominent than in the
higher strata.
In the Norway Deep, a baric maximum leans up to
its southern margin. The downward motion proceeding
thence results i Pl. XXIII) in a temperature-maximum.
It will be observed that in this basin the gradients
point northward. But they are steeper on the east
side than on the west. Hence the horizontal motion
must yield to the former, and set northward on the east
side, southward on the west side, and eastward on the south
side. On the west side, where the motion proceeds against
the gradient, it will be downward. As well Pl. XXIII as
Pl. XXV shows it to be the cold water from the
Jan-Mayen Channel that here seeks a downward passage along
the bottom. On the east side, the motion goes with the
gradient, possibly with acceleration, and with ascension
towards the minimum of pressure in lat. 08° N. A strong
suction of cold water from below is the result, and
simultaneously a suction of water along the southern margin ol’ the
basin. The effect here however is weaker, since the
maximum of pressure forces downward the higher strata, and
since the water of the deep must in part be given off to the
Færoe-Shetland Channel. The full effect of the
maximum-pressure becomes first apparent in the middle of the basin,
where the isotherm for — 1° (Transverse Section X. PI.
X, Station 52, and Pl. XXVI) reaches down to a
considerable depth.
In lat. (57° to (58° N, the cold water from the Jan-
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