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Long-term variation of stratospheric aerosols observed with lidars over Tsukuba, Japan, from 1982 and Lauder, New Zealand, from 1992 to 2015

Authors
Sakai T., Uchino O., Nagai T., Liley B., Morino I., Fujimoto T.
Journal
J. Geophys. Res. Atmos., 121
DOI
10.1002/2016JD025132
Abstract

Vertical distributions of stratospheric aerosols have been measured with lidars over Tsukuba, Japan, since 1982 and Lauder, New Zealand, since 1992 to study the long-term and seasonal variations and influences of climate change. After volcanic eruptions of El Chichón in 1982 and Mount Pinatubo in 1991, the vertically integrated stratospheric aerosol backscattering coefficient (IBC) increased to over 30 times the minimum level over the two sites. The IBC increased to more than twice the minimum over Tsukuba after volcanic eruptions in the northern high latitudes (Okmok, Kasatochi, and Sarychev) and tropics (Nabro) between 2000 and 2011. Over Lauder, the IBC increased to more than twice the minimum after volcanic eruptions in the southern high latitudes (Puyehue-Cordón Caulle and Calbuco) and tropics (Kelud) between 2011 and 2015. The IBC showed seasonal variations with higher values in winter than in summer over the two sites. The mean radiative forcing by the stratospheric aerosols during the period 2000–2015 is estimated to be −0.15 ± 0.07 and −0.13 ± 0.06 W m−2 over the two sites, which partially canceled the increase of global mean radiative forcing by CO2.