Analysis of the Stratospheric Aerosol Load After the 2019 Raikoke Eruption

Sammanfattning: The stratospheric aerosol load after the eruption of Raikoke in 2019 have been analysed with satellite data from the CALIPSO satellite. The goal was to see how much the stratospheric aerosol load increased due to the Brewer Dobson circulation, and further, how this affected the stratospheric aerosol optical depth (AOD), and the corresponding radiative forcing (RF). This was done by performing a data analysis of the backscattering data retrieved from the CALIPSO satellite. The results showed a doubling of the stratospheric aerosol load six months after the eruption, an increase in the stratospheric AOD, and decrease in the RF in the northern hemisphere. The peak AOD found was 0.02 which occurred three months after the eruption, and the corresponding peak value of the RF was -0.5 W/m2. When compared to similar eruptions such as Sarychev 2009, it was assumed that the stratospheric aerosol load went back to normal conditions after one year, since only six months after the eruption were studied in this analysis. Hence, it could be concluded that the eruption increased the stratospheric aerosol load in the northern hemisphere, and therefore affected the climate. This showed that future work, including analysis of the stratosphere after volcanic eruptions, is important to understand the impact it has on the climate.