14 
29,3% (the monthly mean was 26,3—82,4° 00); at Aalborg it was during the same 
period on an average 23,5"/00 (18,4—27,7°/o0). At the same time the monthly mean 
temperature at Oddesund alternated between -—-0,2° (Febr.) and 18,5° (July). At Aal- 
borg it alternated between —1,4° and 18,3°. The conditions characteristic of the 
Limfjord are: a relatively high salinity, especially in the western part, a higher 
summer temperature than in the open waters and the absence of a salter under- 
layer with smaller alternations in the temperature. 
In the northern Kattegat, north of Læsø, an active exchange takes place 
between the surface-current and the under-current, which is. the reason why the 
salinity decreases considerably in both from north to south. As a rule the salinity 
of the water streaming in at Skagen is between 30 and 35°00, and the salinity 
of the surface-water is ordinarily more than 25°. According to J. P. JACOBSEN 
the result of daily observations for 1880—1905 shows, that the temperature and 
salinity at Skagens Reef vary on an average in the following manner; 
Temperature Salinity 
0 M......... 2,5°—16,2° (mean 8,8°) 27,3—31,4 
202) ees Gages 3° —15° 32,3—33,8 
SEI er: 4° —13,9° (mean 8,2°) 33,3—34,5 
At Læsø Trindel the salinity, according to the charts in J. P. JACOBSEN’s 
paper, is: at 0 M. 23—27°/o0, at 10 M. 28—29°%oo, at 20 M. 31—32 9/00. 
In the eastern Kattegat the salinity of the surface water gradually de- 
creases southward; not nearly so great an exchange however occurs here as in the 
northern Kattegat. 
At Anholt’s Knob the salinity is at 0 M. 19—230/6, at 10 M. 23—250/0, at 20 M. 
29—31" co and at the same place the temperature alternates at the surface between 
1,6° (mid. Febr.) and 17° (ca. 1. Aug.) at a depth of 28 M. between 4,2° and 13,5°, 
at a depth of 40 M. between 4° and 11,5°. 
In the western Kattegat (Km.), which is only of small depth, the salt 
bottom water is absent, except in Læsø Channel. At the lightship in Læsø Channel 
in 1880—94 the averages were: 
Temperature Salinity 
mean minim. mean max. mean minim. mean max. 
OM........ 2,2° (Febr.) 16,1° (July) 2239100. 27,80/ou 
DAN 3,4° (March) 13,9° (Aug., Sept.) 32.2 oo 33,9 2/00 
The salt water coming through the Læsø Channel causes on mixing the water 
in this region to become relatively saline, especially to the north and along the 
coast of Jutland. In the greater part of the region the salinity at the bottom is 
however not more than 2500. 
In the Southern Kattegat and the waters east of Samsø the salinity at the 
surface is fairly uniform. In this area there is, especially in summer at a depth 
of 10—20 M., a very distinct limit between an upper layer, which has ca. 20°00 
