WEATHER 



In the past ice-patrol cutters have maintained a comprehensive pro- 

 gram for weather observations. However, this year no patrol cutters 

 were used, so that no such program was possible. The oceanographic 

 vessel, USCGC Evergreen, made six-hourly surface reports during 

 the whole season. This year ocean weather station D at 45°00' N., 

 43°00' W., was continuously occupied. As long as the station con- 

 tinues to be occupied, future w^eather programs of the International 

 Ice Patrol will probably be limited to six-hourly surface weather 

 observations by the surface patrol vessels and the oceanographic 

 vessel. 



In Bulletin 33 of this series an analysis of meteorological condi- 

 tions prior to and during the 1947 season was made to find out 

 what effect abnormal barometric pressure distributions had on sea 

 ice and icebergs. A similar analysis was attempted for 1949. In one 

 respect, the 1949 season was similar to the 1947 season. The predic- 

 tion by use of the Smith formulae was for a slightly heavier than 

 normal ice year in 1949, which was true of the 1947 season. Data 

 for months previous to March 1949 were not obtainable, but daily 

 synoptic charts prepared by the aerological office of the Naval Air 

 Station at Argentia for 0630 G.C.T. were obtained for March 

 through 15 June. On each chart an area of rectangular shape 600 

 miles by 180 miles was drawn stretching along the Labrador-New- 

 foundland coast with its inshore long side running from 55° N., 

 57° W., to 46° N., 50° W. The barometric pressure gradients along 

 each pair of sides were averaged for each available chart to get the 

 gradient components which might be considered to apply to the area 

 centered at about 51° N., 51° AY. Each component of the gradient 

 (normal and parallel to the coast) was averaged for the month and 

 the monthly averages resolved to get a resultant average gradient 

 for each month from March through 15 June. The long dimension 

 of the rectangle is oriented at about 3351/2° and 1551/2° true. As the 

 Avind runs across the isobars at an angle of about 30° to the left at 

 the surface in this region and as the drift of floating sea ice (as a 

 direct effect of the wind) is to the right of the wind by a variable 

 amount approximating 45°, the ice drift has been taken as being 

 directed 15° to the right of the geostrophic wind, the approximate 



Month 



March 1949--. 



April 1949 



May 1949 



1-15 June 1949 



Direction of 

 wind drift 



Degree 



049 

 218 

 120 

 142 



Gradient 



0.0106 

 .0055 

 .0089 

 .0125 



Wind 



8.0 

 4.2 

 6.7 

 9.5 



40 



