13 



a bottoni-cuiient through (he channels in the Sound and the Belts, especially the 

 Great Belt, while a surface-current streams out from the Baltic in an opposite 

 direction. On account of the rotation of the earth this northward so-called Baltic 

 Current is forced eastward and consequently remains on the eastern side of the 

 Kattegat along the Swedish coast, and for the same reason the north-going surface- 

 water moves more rapidly in the Sound than through the Belts. Vice versa the 

 salt bottom-current is forced westward. The boundary between the two w^ater-layers 

 is vei'y distinct in summer, while the transition is uniform in winter. 



The salinity does not vary much in ttae North Sea. At the lightship on 

 Horns Reef the conditions in the years 1880 — 94' were: 



Temperature Salinity 



Mean minimum Mean max. Mean minimum Mean ma.\. 



M 2,2° (Febr.) 15,8° (Aug.) 32,7 "/oo 33,2 



23 - .... 2,6° (March) 15,5° (Sept.) 33,1 "/oo 33,7 "/oo 



The numbers are the averages of the monthly means; the variations are thus 

 a little greater than indicated by the numbers. Along the coast a narrow and not 

 very deep margin occurs with a somewhat lower salinity. 



The conditions in the part of the Skagerak which lies nearest Jutland are 

 essentially like the corresponding part of the North Sea, the water mainly strea- 

 ming from the North Sea towards the Swedish coast. 



In the waters inside the Skaw (Skagen), at every place where the depth is 

 considerable, an upper, relatively not very salt layer, the temperature of which 

 almost constantly follows that of the air, can be distinguished from a deeper layer 

 with Salter water and with special conditions as to temperature. With regard to 

 the surface water, the highest temperature of the year is commonly observed in 

 the beginning of August and is in the greater part of the waters on an average 

 16°, while the lowest temperature of the year, which on an average is 2°, is or- 

 dinarily observed in the middle of February. In fjords and bays, where the renew- 

 al of the water is not considerable, the maximal temperature is however higher 

 and falls in July, and the minimal temperature is lower in winter. In the deeper 

 and Salter water-layers both the maximal temperature and the minimal temperature 

 occur later than at the surface, and the maximum temperature is lower than at 

 the surface, the minimum temperature higher. The differences from the surface 

 are various but are essentially regulated by the depth. 



With regard to the hydrography of the Linifjord only some few observations 

 are available. In this shallow water there is only a small difference between the 

 surface and the deeper water-layers. The water in the western part is most like 

 that of the North Sea, the eastern part like the surface-water of the Kattegat. It 

 is only for Oddesund and Aalborg that continuous observations on the surface- 

 water are available. In 1902 — 1906 the salinity at Oddesund was on an average 



' Meteorologisli Aarljog for 1896. 



