Global Climate Response to the Tambora Eruption

An ocean atmosphere data record spanning the years from 1815-2013 is used to explore the climate response to the Tambora eruption that occurred in April 1815. The data record is composed of two loosely-coupled reanalysis products: the 20CR (20^thCentury Reanalysis) system for the atmosphere and the SODAsi (Simple Ocean Data Assimilation – sparse input) system for the ocean. Although not directly coupled, the two reanalysis systems are coupled iteratively by exchanging surface boundary conditions. This system is significant because although there are few oceanic observations for period following the Tambora eruption, there are surface pressure observations that are used by the atmosphere reanalysis. Thus information from atmosphere gets into the ocean reanalysis.

The results show a robust response in both the atmosphere and the ocean in the year following the eruption. A region of anomalous low pressure is forced in the North Pacific that is connected to an anomalous SST (Sea Surface Temperature) cooling that reaches -3 degrees Celsius. Although weaker, there is also a response in the North Atlantic. Heat fluxes show a complex pattern of response, and show that ocean dynamics are required to explain the SST anomalies.