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100
Vedkommende afsattes Observationerne paa et særskilt Kart
for hvert af de ovennævnte Expeditionsaar samt for de
norske og danske Skibsobservationer, og paa hvert af disse
Karter droges de til Temperatursystemet horende
Isother-mer. For flere Systemers Vedkommende var dette et let
Arbejde, f. Ex. for vor Nordhavsexpedition. For andre
Systemer, hvor Observationerne vare mindre regelmæssig
fordelte, maatte disse forst samles i Grupper, og
Middeltallet af disse beregnes og indfores paa den Plads, der
indtoges af Gruppens Tyngdepunkt. Dernæst construerede jeg
for hver Breddegrad, fra den 80. til den 55., efter de
nævnte Isothermer, Curver, der viste Temperaturens
Stor-relse langs hver Breddegrad i hvert Observations- eller
Aars-System. Efter Antallet af disse fik jeg saaledes paa
do Partier, hvor Systemerne overskar vedkommende
Breddeparallel, Curver eller Stumper af Curver for
Havoverfladens Temperatur til forskjellige Aar eller Rækker af
Aar. Af de forskjellige Curvers Ordinater toges Middeltal,
og gjennem de til dem svarende Punkter droges en
Me-diumscurve, der, saavidt det benyttede Materiale tillod,
fremstiller Temperaturens normale Stand langs vedkommende
Breddeparallel i Midten af August. Beregningen af
Middeltallene, der kunde uddrages af fra 2 indtil 7
Enkeltværdier, har ogsaa kunnet tjene til at finde den
gjennemsnitlige Afvigelse af et enkelt Aars Observation fra det
normale Medium og Maximum afvigelsen. Paa de fundne
normale Curver afsattes deres Skjæringspunkter med de
horisontale Linier for hver hel Grad, og disse Punkter
overfortes paa et Kart paa de tilsvarende Længder. Gjennem
de saaledes fundne Snitpunkter droges derpaa Havfladens
Isothermer.
For Østhavets og Danmarkstrædets Vedkommende
bleve Observationerne samtlige afsatte i samme Kart, og
inddelte i Grupper, hvis Middeltal indtegnedes i Gruppens
Tyngdepunkt, hvorpaa Isothermerne droges efter disse
Media. Ved Beregningen af Gruppemiddeltallene er der. for det
nordlige Østhavs Vedkommende —
Øst-Spidsbergen-Nord-Novaja-Semlja —, taget Hensyn til, at Observationerne
falde i gunstige Is-Aar. For hvert saadant er i
Middeltallets Beregning indtaget som Compensation en Temperatur
af —1°. Herved tror jeg at være kommen det normale
Temperaturmedium nærmere.
Resultatet af disse Construction er og Beregninger
foreligger i Kartet PI. XXVII. Ifølge 54 forskjellige
Bestemmelser, der variere mellem 0°.4 og 1°.5, er i
Gjenneinsnit den midlere Afvigelse af en enkel (et enkelt Aars)
Tcmperaturobscrvation paa et Sted fra den normale + 0°.90,
og man tør saaledes, da det gjennemsnitlige Antal af
Observationer for hvert Medium er 5.G, sætte Usikkerheden
af Kartets Temperaturangivelse for et enkelt Sted til + 0°.38.
De forskjellige Breddegrader udvise ikke nogen merkelig
Forskjel i denne Henseende. Den midlere Maximumsaf-
the Norwegian Sea, the observations were put down on
separate maps, one for each year of the above-mentioned
Expeditions, as also for the Norwegian and Danish vessels,
and on each of these maps were drawn the isotherms
resulting from the system of observations. With several of
the systems, this was an easy matter, e.g., with that from
the North-Atlantic Expedition. With other of the systems,
in which the observations occurred loss regularly distributed,
these had first to be collected into groups, and the mean
computed and placed where the group was found to have
its centre of gravity. I then constructed for each parallel
of latitude, from the 80th to the 55th, by means of the
fore-mentioned isotherms, a corresponding number of curves,
exhibiting the course of the temperature along each parallel
of latitude in every observing or yearly system. According
to the number of such, I obtained, therefore, in the tracts
where the systems cut the respective parallel of latitude,
curves or fragments of curves for the temperature of the
sea-surface in different years or series of years. Of the
various curve-ordinates was taken the mean, and a mean
curve was then drawn through the points corresponding
to the said mean numbers. This curve represented, so far as
the material made use of would admit, the normal
distribution of temperature along the respective parallel of latitude
in the middle of August. The computed mean values, based
on from 2 to 7 single determinations, have likewise served to
find the average deviation of a single year’s observation
from the normal mean and the maximum deviation. On the
normal curves thus found, the points of intersection with
the horizontal lines for every whole degree, were marked ofl’
and these points transferred to a map along the
corresponding degrees of longitude. Through the points of
intersection thus found, the isotherms of the sea-surface
were then drawn.
As regards [the Barents Sea and Denmark Strait,
all the observations were put down on one and the same
map, and arranged in groups, the means for which being
placed in the centre of gravity of the group, after which
the isotherms were drawn from these means. When
computing the mean number for each group, regard had to be
taken, as concerns the northern tract of the Barents
Sea, viz., East Spitzbergen-North Novaja Semlja, that the
observations are derived from favorable ice-vears. For
every such observation, a temperature of —1° has been
introduced as compensatory in calculating the mean. Thus
I make venture to assume I have reached a closer
approximation to the normal mean temperature.
The result of these constructions and computations
is given in the Map, Pl. XXVII. According to 54
different determinations, varying between 0°.4 and 1°,5, the
mean deviation of a single (a single year’s) observation of
temperature from the normal average in any given place is
+ 0°,90; and therefore, since the average number of
observations for each mean is 5.G, we may put the uncertainty of
the Map’s indication of temperature for any given place at
+ 0°,38. The various parallels of latitude do not exhibit
any appreciable difference in that respect. The mean max-
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