Mapping atmospheric aerosols with a citizen science network of smartphone spectropolarimeters

“To assess the impact of atmospheric aerosols on health, climate, and air traffic, aerosol properties
must be measured with fine spatial and temporal sampling. This can be achieved by actively involving citizens
and the technology they own to form an atmospheric measurement network. We establish this new
measurement strategy by developing and deploying iSPEX, a low-cost, mass-producible optical add-on
for smartphones with a corresponding app. The aerosol optical thickness (AOT) maps derived from iSPEX
spectropolarimetric measurements of the daytime cloud-free sky by thousands of citizen scientists throughout
the Netherlands are in good agreement with the spatial AOT structure derived from satellite imagery
and temporal AOT variations derived from ground-based precision photometry. These maps show
structures at scales of kilometers that are typical for urban air pollution, indicating the potential of iSPEX
to provide information about aerosol properties at locations and at times that are not covered by current
monitoring efforts.”
(Citaat: Snik, F., Rietjens, J.H.H., et al. – Mapping atmospheric aerosols with a citizenscience network of smartphone spectropolarimeters – Geophysical Research Letters (2014))