352 



BIKKELAND. THE NORWEGIAN AURORA POLARIS EXPEDITION, igO2 1903. 



If we look at the conditions at Bossekop, we find, as already mentioned, a peculiar strengthening 

 in the positive deflections in the horizontal-intensity curve, just at the time when the negative storms 

 are at their height. This, as we have said, may be explained directly as an effect of the positive storm; 

 but we will here draw attention to the fact that it is also possible to explain the conditions as effects 

 of the negative system lying to the north, if we assume the point of convergence of the system to be 

 situated to the north of Bossekop. Lastly, it is possible that these two factors act simultaneously, and 

 this might perhaps be the most probable explanation. 



At the southern stations, the conditions seem mainly to be ruled by the positive polar storm. We 

 here find a distinct, well-defined deflection in the horizontal-intensity curve in a negative direction; where- 

 as in declination we find only deflections of small amplitude. These are first directed eastwards, and 

 then, at about 15'' 20, turn round. The current-arrow in these regions turns distinctly clockwise for a 

 certain angular distance. This, it must be assumed, would indicate that as the point of divergence of 

 the positive system is situated to the north of these stations, as PI, is negative, the system of precipi- 

 tation now would be moving, although only slightly, eastwards. As we have learnt in Part I, it is just 

 such a deviation of the current arrow that marks a movement of the system of precipitation. As, how- 

 ever, we have so few stations in the positive area of precipitation, it is scarcely possible to prove with 

 any great degree of certainty the existence of such movement by the aid of our observations from the 

 arctic regions. 



If we look, lastly, at the perturbing forces in the vertical intensity, we find that at Pawlowsk they 

 are in accordance with the fact that that place is situated in an area of divergence, as P v there is positive. 

 At Gottingen also, we find evidently positive deflections in the vertical-intensity curve at the time the 

 perturbation is in progress. This is apparent on a direct consideration of the curve. We have not taken 

 out any perturbing forces, however, as the position of the mean line is rather difficult to determine from 

 the data at our disposal. Its determination would therefore be too uncertain, and the values obtained 

 might possibly give misleading ideas of the actual conditions. In this first section, however, there seems 

 to be no doubt as to the direction of the deflections, although they cannot easily be given decided values. 



At Bossekop we find a well-defined positive deflection in the vertical curve. This should indicate 

 that the positive system of precipitation exerted a distinct influence here, and was situated to the north 

 of the place, for the negative system that is found still farther north, would here occasion deflections to 

 the opposite side. If the actual perturbation-conditions at Bossekop are in accordance with the observa- 

 tion taken, it must necessarily be supposed that the effect of the positive system extends thither. This 

 is moreover natural, to judge from the conditions at Pawlowsk, where there are strikingly clear proofs 

 of the effect of the positive system. While there are thus positive deflections in the vertical-intensity 

 curve at Bossekop and Pawlowsk, at Sodankyla the deflections are as usual in exactly the opposite 

 direction. The probable explanation of this has already been mentioned. 



On Charts I and II, for the hours // 20'", // /"', // 20, 14'' jo">, //'' //'" and i6 h 20'", all 

 these conditions come out very distinctly. On the night side, from Fort Rae, through Uglaamie, to Ssa- 

 gastyr, extends the great negative system of precipitation. 



A kind of continuation of this is found at Cape Thordsen and Fort Conger, or it might be sup- 

 posed that a more or less independent system is at work there. 



At Kingua Fjord the direction of the arrow is distinctly southerly, but swings round from east at 

 I3 b 2o m at which hour the storm thus really seems to belong to the positive system of precipitation to 

 a fairly decided west at the close of the period, which would indicate that a negative polar storm was 

 then acting. The transition from the more positive to the more negative character of the storm does 

 not, however, take place so discontinuously as we are accustomed to find at Little Karmakul, for instance 

 where we very frequently find such reversals. On account of the fairly constant direction of the current- 



