How does the Pinatubo eruption influence our understanding of long-term changes in ocean biogeochemistry? | CU Experts

Pinatubo erupted during the first decadal survey of ocean; biogeochemistry, embedding its climate fingerprint into foundational; ocean biogeochemical observations and complicating the interpretation of; long-term biogeochemical change. Here, we quantify the influence of the; Pinatubo climate perturbation on externally forced decadal and; multi-decadal changes in key ocean biogeochemical quantities using a; large ensemble simulation of the Community Earth System Model designed; to isolate the effects of Pinatubo, which cleanly captures the ocean; biogeochemical response to the eruption. We find increased uptake of; apparent oxygen utilization and preindustrial carbon over 1993-2003.; Nearly 100% of the forced response in these quantities; are attributable to Pinatubo. The eruption caused enhanced ventilation; of the North Atlantic, as evidenced by deep ocean chlorofluorocarbon; changes that appear 10-15 years after the eruption. Our results help; contextualize observed change and contribute to improved constraints on; uncertainty in the global carbon budget and ocean deoxygenation.

VIVO