Increase in background stratospheric aerosol observed with lidar at Mauna Loa Observatory and Boulder, Colorado

摘要: [1] The stratospheric aerosol layer has been monitored with lidars at Mauna Loa Observatory in Hawaii and Boulder Colorado since 1975 2000, respectively. Following the Pinatubo volcanic eruption June 1991, global stratosphere not perturbed by a major providing an unprecedented opportunity to study background aerosol. Since about increase of 4–7% per year backscatter altitude range 20–30 km detected both Boulder. This is superimposed on seasonal cycle winter maximum that modulated quasi-biennial oscillation (QBO) tropical winds. Of three causes for increase: emissions stratosphere, increased upwelling, anthropogenic sulfur gas troposphere, it appears large coal burning 2002, mainly China, likely source dioxide ultimately ends up as sulfate responsible from layer. The results are consistent 0.6–0.8% tropospheric entering stratosphere.