Hi. 
Havets Stromninger. 
i. Lufttrykket. 
At Stromningerne i Havets Overflade for en meget 
veesentlig Del fremkaldes ved Vinden, tor man efter de 
senere Tiders Undersøgelser anse for tilstrækkelig godtgjort. 
Ligeledes er det bevist, at Vindens Virkning paa Havets 
Overflade forplanter sig til Dybet, og at det er Resultanten 
af de paa Overtladen virkende Vinde, der er bestemmende 
for Havets gjennemsnitlige stadige Bevægelse. 
For at studere denne Bevægelse i dens Forhold til de 
virkende Kræfter er det saaledes nødvendigt at kjende den 
gjennemsnitlige Retning og Hastighed af Vmden, dens Re- 
sultant for Aaret, paa den Strækning af Havet, hvis almin- 
delige, gjennemsnitlige Bevægelse man vil undersøge. 
Paa de tleste Steder vexle de herskende Vinde i Aarets 
Løb baade i Retning og Styrke. Virkningen af en saadan 
Vexling forplanter sig dog ikke langt ned under Overfladen, 
og den aldeles overvejende Del af Havets Vandmasse faar 
sin Bevægelse reguleret efter de periodisk vexlende Kreef- 
ters Resultant for lange Tidsrum. 
Idet vi gaa ud fra, at Havvandets regelmæssige, sta- 
dige Bevægelse har opnaaet at blive constant med Hensyn 
til Tiden, som en Virkning af Aarsagernes seculære Ar- 
bejde, gjælder det at finde et Udtryk for Vindens midlere 
Retning og Hastighed for det tilsvarende Tidsrum. I Be- 
tragtning af den korte Tid, der er hengaaet, siden man først 
begyndte at udføre og samle meteorologiske Tagttagelser, 
maa den Fremstilling, jeg kan give af Vindens Retning og 
Hastighed for det normale Aar, blive foreløbig og, for vig- 
tige Bgnes Vedkommende, hvorfra Tagttagelser ere yderst 
sjeldne eller endog ganske mangle, endnu beheftet med stor 
Usikkerhed. Imidlertid vil den, støttet som den er af den 
Kundskab, Meteorologien har erhvervet om den Indflydelse, 
Fordelingen af Land og Hav har paa de herskende Vinde, 
kunne afgive et godt Udgangspunkt for videre Studium, og 
1 
Zoppritz. Wiedemanns Annalen der 
Nb JM, 100, S. 582. 
Physik und Chemie, 
UL 
Ocean Circulation. 
I. Atmospheric Pressure. 
That the currents of the surface of the sea are ocea- 
sioned very materially by wind, we may regard as a fact to 
which researches of recent date have given full confirmation. 
It has likewise been shown,! that the effect of the wind on 
the surface of the sea becomes propagated to the deep; 
and moreover, that it is the resultant of the winds acting 
on the surface which determines the average steady motion 
of the sea. 
Hence, for studying this motion in its relation to the 
operative forces, it is manifestly imperative to know the 
general direction and velocity of the wind, i. e. its annual 
resultant throughout the tract of ocean where the general 
average motion is sought to be determined. . 
In most localities, the prevailing winds are found to 
vary in the course of the year, alike as to direction and foree. 
The effect of such variation, however, does not become 
propagated far beneath the surface; and by far the greater 
part of the water of the sea has its motion regulated by 
the resultant of the periodically varying forces for long 
spaces of time. 
Now, starting from the fact of the regular and steady 
motion of the sea having become constant in regard 
to time, as an effect of the secular agency of its causes, 
we must seek an expression for the wind’s mean direc- 
tion and velocity for the corresponding period. Consid- 
ering the short period that has elapsed since any attempt 
was first made to carry out and collect meteorological ob- 
servations, the representation I can give of the wind’s 
direction and velocity for the normal year must needs be 
preliminary, and in regard to important tracts, where ob- 
servations are exceedingly scarce, nay wanting altogether, 
as yet be clogged with great uncertainty. Meanwhile, it 
cannot fail, supported as it is by the knowledge meteoro- 
logy has acquired of the influence which the distribution 
of land and water exerts on the prevailing winds, to 
1 Zoppritz. Wiedemanns Annalen der Physik und Chemie, 
N. Fi. TE, p. 582. 
