Fig. 3.
Changes in the distribution of ozone at available sites with the longest Antarctic (Syowa; Upper) and Arctic (Resolute; Lower) records at 70 (±2) mbar (≈18 km as in Fig. 2) for September and March since 1960. Symbols show the midpoints of bins for each grouping of data in these probability distributions. PPMV, parts per million by volume.
