INFLUENCE OF GLOBAL VOLCANIC PROCESSES ON CLIMATE MODULATION IN THE SOUTHWESTERN US

Long-term climate-change is often attributed to alterations in geologic processes, such as volcanic aerosols. The fractal transformation of reconstructed temperature reveals a strong relation among large-scale global volcanic events (volcanic explosivity index > 5) and climate-change variables across the southwestern United States. Over the 2,000 year period of record, volcanic events tend to result in cooling periods that last from 20 to 150 years. These cooling periods are followed by warming period that continue until another volcanic event occurs. On average, the trend in warming-cooling over this period appears to be at (or near) steady-state equilibrium. This finding suggests that geologic processes are likely to be the primary factor in regulating climate change across this region.