426 YOUNG, ERICKSON, AND FAIRHALL 150 140 |! = T ! T | iE ~ af A, ARLIS II Oo, POINT BARROW OD, BROWN BEAR VESSEL _, 130 |= < _ g, SEATTLE = ac QO Z 120 -- g | > a < 110 -— — z rd = Y — } ™~ I 100 ;- = 90 F- 4 80 4be | AUG, | SEPT, | = NOV. 1963 oe JAN. FEB, MAR. APR. | MAY i JUNE JULY 1964 Fig. 2—Specific 4*C content of atmospheric CO>2 relative to pre-1945 levels, An increase in '*C specific activity is associated with injection of CO, of high specific activity from the stratosphere. Evidently the rate of injection from the stratosphere predominates over exchange with the ocean during the summer and vice versa during the fall and early winter. It is of interest to note that the amount of exchange of CO, between the atmosphere and the ocean which is necessary to explain the decrease in the 4c specific activity during the fall months amounts to about one-fifth of the tropospheric CO,, assuming there is no injection of CO, of high specific activity from the stratosphere during this period. However, since there probably is an injection of CO,of high specific activity, then more than one-fifth of the troposphere must have exchanged with the ocean. This implies a more rapid exchange of CO, between the atmosphere and the oceans than has previously been estimated,27> An experiment to test the role of storms in bringing down strato- spheric air into the troposphere is illustrated in Fig. 3. During the period from Apr. 9 to 11, 1964, a particularly well-developed system of three storm fronts passed in rapid succession over the northwest.