MARINE ALGAL VEGETATION 45 



As shown by the figures there is a considerable difference in 

 the amount of precipitated moisture. That of Thorshavn is greatest, 

 next come the Vestmannaeyjar, followed by Berufjor5ur. The preci- 

 pitation at Stykkisholmur is not more than half that in the Vest- 

 mannaeyjar, and that of Grimsey is not more than a fourth part 

 of that in the Vestmannaeyjar. 



b. Mean Amount of Cloud (Willaume- Jantzen, 1. c.). 

 Scale 010. 



Winter Spring" Summer Autumn 



E. Icel. Berufjordur (23 years) 6.4 6.6 6.9 6.6 



N. Icel. Grimsey (22 years) 8.5 8.2 7.9 8.5 



S\V. Icel. Stykkisholmur (22 years) 7.1 6.4 6.0 6.9 



S. Icel. Vestmannaeyjar (18 years) 6.2 6.1 6.1 6.3 



Thorshavn in the Faeroes (25 years).. 7.4 7.1 7.7 7.5 



The amount of cloud is greatest in Grimsey, and there is no 

 great difference between the remaining three coast-stations in Ice- 

 land. In Thorshavn, however, the amount of cloud is considerably 

 greater and consequently this place approximates to Grimsey. 



c. Foggy and Wet days. Mean number of Foggy days (Wil- 

 laume-Jantzen, 1. c.). 



Winter Spring Summer Autumn The year 



E. Icel. Berufjordur (23 years). 44.0 52.0 67.0 49.0 212 



N. Icel. Grimsey (22 years) ... 2.4 13.0 31.0 7.0 53 



SW.Icel.Stykkisli61mur(22 years) 1.0 2.6 4.1 1.3 9 



S. Icel. Vestmannaeyjar (18 years) 7.0 12.0 21.0 12.0 52 



Thorshavn in the Faroes (25 yrs.) 3.0 10.0 29.0 9.0 51 



The number of foggy days in Berufjor5ur is remarkably high, 

 and at Stykkisholmur is extremely low. In Grimsey the number is 

 much lower during the winter months, and higher during the 

 summer months than it is in the Vestmannaeyjar; there are also 

 small differences during spring and autumn. There are only small 

 differences between the Faeroes and the Vestmannaeyjar, except in 

 the winter, when the Vestmannaeyjar have twice as many foggy days. 



Mean number of Wet days (Willaume- Jantzen, 1. c.). 



Winter Spring Summer Autumn The year 



E. Icel. Berufjordur (23 years). 52 43 34 48 177 



N. Icel. Grimsey (22 years) ... 40 29 29 45 143 



S\V.Icel.Stykkisholmur(22 years) 58 47 40 52 197 



S.Icel.Vestmannaeyjar(18years) 64 55 47 59 225 



Thorshavn in the Faeroes (25 yrs.) 81 66 58 74 279 



At all seasons the number of wet days is highest in the Faeroes 



