We have used a high resolution infrared spectrometer aboard the NASA Wallops Flight Facility Electra aircraft to measure the total column amount of SO2, O3, and HCl above the aircraft while flying over the Caribbean three weeks after the June 15 eruption of Mt. Pinatubo in the Philippines. South of 20 ¿N latitude we observed columns of SO2 ranging from 2.0¿106 to 3.7¿1016 molecules-cm-2. In addition, the column amount of HCl averaged 1.5¿1015 molecules-cm-2 in the region of the plume. This may represent a small increase in HCl above the amount, estimated from our previous measurements, that would have been present had there been no volcanic eruption, but the increase is substantially less than that seen following the 1982 eruptions of El Chich¿n [Mankin and Coffey, 1984>. ¿American Geophysical Union 1992