Volcanic eruptions provide a natural experiment to observe the time constants for the onset and decay of consequent radiative perturbations. Harries and Futyan studied atmospheric conditions following the 1991 eruption of Mt. Pinatubo in the Philippines. Using atmospheric records before and after the event, the authors analyzed the growth and decay of perturbations in atmospheric temperature, humidity, and radiative fields following the eruption. They were able to quantitatively distinguish between processes that respond quickly to the insertion of aerosols into the atmosphere, such as the shortwave and longwave fluxes at the top of the atmosphere, and those which evolve on slower timescales, such as changes in the humidity and temperature fields. The authors suggest that a valuable test of coupled climate models should be whether they correctly reproduce these response times after a volcanic eruption.
By American Geophysical Union