FINNISH METEOROLOGICAL INSTITUTE (FI)
Stratospheric aerosols play an important role in the Earth system and in the climate. Through the scattering of solar radiation back to space and by heating the stratosphere through the absorption of thermal infrared radiation upwelling from the troposphere, stratospheric aerosols impact the radiative forcing and thus the energy balance of the Earth’s atmosphere. By providing a surface for heterogeneous reactions, which release halogens, stratospheric aerosols contribute to the catalytic depletion of ozone. Since there is a strong coupling between the stratospheric aerosols, the stratospheric ozone amount, the thermal balance and the dynamics of the atmosphere, it is essential to consider realistic aerosol information in modelling studies and interpretation of the measurements related to the stratosphere. The information about stratospheric aerosols and their influence on climate is also of high importance for analyses related to geoengineering.
One of the characteristics widely used to describe the amount of stratospheric aerosol is its extinction coefficient. At a first approximation the aerosol extinction coefficient can be used to estimate the radiative forcing and thus quantify the implication for ozone and climate change. While several data sets of the stratospheric aerosol extinction coefficient exist there are only a few studies jointly analyzing aerosol records from multiple instruments.
The purpose of this project is to elaborate methods to merge aerosol extinction coefficient records from solar/lunar/stellar occultation and limb-scatter instruments and create a merged longterm multi-mission aerosol record. The objective is to increase the reliability of the data set by including multiple instruments measuring similar atmospheric quantities in the post-SAGE II period.