165 
Havvandets Tæthed, som atmosfæriske Aarsager fremkalde 
paa de forskjellige Steder. 
9. Strømfladen. 
Vi have ovenfor seet, hvorledes de af Vindene frem- 
kaldte Stromninger betinge den Overflade, jeg kalder Vind- 
fladen. Af Vindfladens Heldninger kan man omvendt 
beregne Vind-Strømmenes Retning og Hastighed. Paa 
samme Maade fremkalder ogsaa Tæthedsfladen sit Strøm- 
system. Havets Overflade holdes stadig i Bevægelse baade 
af de herskende Vinde og ved Tæthedernes ulige Fordeling. 
Den resulterende Bevægelse betinger en Overflade, der 
bestemmes saaledes, at dens verticale Coordinater over en 
Niveauflade ere Summen af Vindfladens og Tæthedsfladens 
Coordinater i samme Punkt. Denne Flade kalder jeg 
Strømfladen. Af dens Heldninger kunne Havoverfladens 
virkelige, normale Bevægelser beregnes. 
I den følgende Tabel er angivet Vindfladens og Tæt- 
hedsfladens verticale Coordinater for de samme Stationer, der 
have tjent til Construction af Tæthedsfladen. Vindfladens 
Ordinater ere tagne ud af Kartet Pl. X XXIII. Hojderne 
ere angivne i Meter. W betegner Vindfladens, D 'Tætheds- 
fladens og S Stromfladens Ordinater. 
Stromfladen. 
Stat. No. P. 54 P. 64 14 24 32 
W 0.595 0.390 0.605 0.690 0.630 
D 0.187 —0.043 0.203 0.448 0.416 
S 0.782 0.347 0.808 1.738 1.046 
Stat. No. 52 94 95 96 99 
W 0.050 0.760 0.750 0.150 0.300 
D 0.021 0.550 0.528 0.085 0.240 
S 0.07 I 1.310 1.278 0.235 0.540 
Stat. No. 184 199 206 213 215 
W 6.200 0.360 0.375 0.001 0.087 
D 0.016 0.1 12 0.080 0.016 —0.016 
S = o2:6 0.472 0.455 0.017 0.071 
Stat. No. 262 268 270 273 275 
W 0.660 9.360 0.260 0.195 0.220 
ID) © em —oo3% —0o0g: 0.000 —0.032 
S 0.724 0.323 0.22 0.195 0.188 
Stat. No. 300 302 303 304 305 
W 0.345 0.465 0.350 0.290 0.220 
D 0.224 0.133 0.011 0.000 —0.OII 
S 0.569 0.598 0.361 0.290 0.209 
Stat. No. 345 347 349 350 351 
W 0.270 0.300 0.430 0.520 0.576 
D 0.032 0.043 0.069 0.192 0.304 
S 0.302 0.343 6.499 0.712 0.874 
in the density of the sea-water which atmospheric causes 
occasion in the various localities. 
9. The Current Surface. 
We have seen above in what manner currents pro- 
duced by the winds determine the form of the surface I 
call the wind-surface. From the inclinations of the wind- 
surface, conversely, we may compute the direction and 
velocity of the wind-currents. In the same way, too, does 
The 
surface of the sea is kept in continual motion, alike by 
the prevailing winds and by the unequal distribution of 
density. The resulting motion requires a surface deter- 
mined by the condition that its vertical co-ordinates, 
reckoned from a surface of level, are the sum of the co- 
ordinates of the wind-surface and of the surface of density 
at the same point. his surface I call the Current-Surface. 
From its inclinations, the true normal motions of the sea- 
surface admit of being computed. 
In the following Table are given the vertical co- 
ordinates of the wind-surface and’ the, surface of density 
for the same Stations that have served to construct the 
surface of density. The ordinates of the wind-surface have 
been taken from the Map, Pl. XXXIIT. The heights are 
given in metres. W denotes the ordinates of the wind- 
surface, D those of the surface of density, and S those of 
the current-surface. 
the surface of density produce its system of currents. 
The Current-Surface. 
34 SIU 40 42 48 dl 
0.395 280 0.195 0.255 0.196 0.090 
—0.069 —0.02I 0.037 0.101 —0.I12 —0.059 
0.326 259 0.232 0.356 0.084 0.031 
107 125 137 148 176 183 
0.690 0.100 0.350 0.710 0.580 0.050 
0.342 0.053 0.208 0.245 0.213 0.021 
1.032 0.153 0.558 0.955 0.793 0.071 
217 226 241 243 245 247 
0.210 0.360 0.360 0.110 0.015 0.020 
—0.059 0.096 0.016 —0.016 —0.016 0.0I I 
O.151 0.456 0.376 0.094 —0.001 0.03 I 
284 291 295 296 297 298 
0.040 0.400 0095 0.045 0.070 0.140 
0.032 0.064 0.OI I 0.027 0.016 0.053 
0.072 0.464 0.106 0.072 0.086 0.193 
306 308 314 323 339 342 
0.155 0.160 0.195 0.160 0.445 0.360 
0.021 0.032 0.085 0.037 0.192 0.112 
0.176 0.192 0.280 0.197 0.637 0.472 
352 353 355 357 351 362 
0.480 0.4.00 0.340 0.435 0.4.70 0.495 
0.112 0.053 0.091 0.320 0.133 0.101 
0.592 0.453 0.431 0.755 0.603 0.596 
