The Jan. 15, 2022, Hunga eruption increased aerosols and H2O in the southern hemisphere stratosphere and then dispersed throughout 2022/3. • Stratospheric water vapor, ozone, temperature, and aerosol optical depth contribute to the change in downward radiative fluxes. • Hunga produced a global change in tropopause downward radiative flux of-0.17 and ±0.07 W/m 2 over the two-year period.