Combining a Joint-Variance Maximization and Pseudo Mass approach to OMI, MOPITT, MISR, CALIOP, and AERONET to Quantify the Spatial-Temporal Changes in Global Aerosol Emissions and Atmospheric Aerosol Absorption Over the Past Decade

Abstract:

Anthropogenic aerosol emissions are geolocated in urban, industrial, and biomass burning areas, each with its own unique chemical, physical, and optical characteristics. Furthermore, trace gasses and heat co-emitted with the aerosols lead to differences in the aerosol height, secondary aerosol formation, coagulation, and/or condensation. This is especially so for absorbing aerosols, which undergo a significant absorption enhancement as they age.

To quantify the spatial/temporal pattern and magnitude of aerosol emissions, a joint-variance maximization technique and pseudo-mass calculation using a mass-cloture approach was made with joint column measurements of NO₂ and CO. The resulting product quantifies global-scale emissions regions, downwind regions, and an estimation of the emissions magnitude. We will show this technique successfully identifies major biomass burning regions except for Northern Canada and Siberia, and most urban regions except for heavily cloudy regional in the tropical belt or Monsoon India. The results also compare excellently with MODIS.

This work extends upon these a priori by using a combination of MISR stereo heights and CALIOP to understand the profile heights over the various types of source regions; multi-wavelength retrievals of AOD and SSA from AERONET in combination with a MIE model to understand the particle size and optical properties; and the AOD from MISR to extend these relationships in space and time as possible. The resulting products quantify the magnitude of increased global aerosol emissions from biomass burning over different continental scale regions, as well as both the increased and decreased urban aerosol emissions in different locations around the world. Furthermore, we discern the changes in the ratios between NO₂ and aerosol emissions and CO and aerosol emissions. These ratios yield information about the fuel undergoing combustion, the temperature of combustion, and the lifetime of aerosols once in-situ.

A first model result using these new emissions shows improved reproduction of long-range transport and urbanization compared with neutral measurements, all without the need for artificial scaling or other intervention. A new range of uncertainties and ideas for further steps required to make additional progress will be discussed.