5:15 PM - 6:30 PM
[ACG35-P04] Simulated impact of the 1815 Tambora eruption on global climate with MIROC-ES2L
Keywords:Earth System model, volcanic impact, climate change
The volc-long-eq experiment in CMIP6 VolMIP is a climate response experiment to an equatorial volcanic eruption with an initial SO2 emission of 56.2 Tg, which roughly corresponds to the scale of the 1815 eruption of Tambora volcano on Sumbawa Island, Indonesia (Zanchettin et al. 2016). This eruption is one of the largest volcanic eruptions in the tropics in the last 500 years and is associated with the "Year without Summer" of 1816. The objectives of this experiment are to focus on the atmosphere-ocean interaction and the interannual and decadal-scale response to large-scale volcanic eruptions on global and regional scales, to investigate the differences in response (uncertainties) among models, and to clarify the role of internal variability as a background field in the climate response to volcanic eruptions. In each member, the 20 years simulations were conducted. Except for the input of volcanic eruptions and related forcing data, the background field is assumed to be the situation in 1850 before the industrial revolution. Due to the timing of past volcanic eruptions assumed in each experiment, the vol-long-eq experiment was started on April 1.
In the volc-long-eq experiment, the decline in shortwave radiation associated with volcanic eruptions ends after about eight months, after which the radiation begins to return. On the other hand, the temperature continues to decrease, peaking about four months later and dropping about 1.0 ºC on average, then recovering. The difference in the timing of the peak between surface air temperature change and the change in radiation caused by the volcanic eruption was found to be due to the positive feedback related to the snow and sea ice in the high latitudes of the Northern Hemisphere and the slow response of ocean.
In the volc-long-eq experiment, the decline in shortwave radiation associated with volcanic eruptions ends after about eight months, after which the radiation begins to return. On the other hand, the temperature continues to decrease, peaking about four months later and dropping about 1.0 ºC on average, then recovering. The difference in the timing of the peak between surface air temperature change and the change in radiation caused by the volcanic eruption was found to be due to the positive feedback related to the snow and sea ice in the high latitudes of the Northern Hemisphere and the slow response of ocean.