Atmospheric dust maps produced from smartphone data

Monday 03rd Nov 2014 by theWeather Club

Measurements by citizen scientists in the Netherlands using their smartphones and a low-cost iSPEX add-on ( are providing accurate data on atmospheric dust particles and are adding valuable information to supplement professional measurements.

The iSPEX app allows participants to scan the blue sky while the smartphone camera takes pictures using the add-on. These photos record the spectrum and the linear polarization of the sunlight that is scattered by dust particles in the atmosphere, thereby providing information about the particles properties.

The iSPEX team - a collaboration between Dutch research institutes (Leiden University, the Dutch Research School for Astronomy (NOVA), SRON Netherlands Institute for Space research, KNMI Royal Netherlands Meteorological Institute, and RIVM National Institute for Public Health and the Environment) - analyzed and quality-checked measurements from thousands of participants over three cloud-free days in 2013 to create unique maps of dust particles at a spatial resolution of 2km across the Netherlands. The data was comparable with, and on some occasions even exceeded, that from professional measurement networks and coarser satellite data.

Team leader Frans Snik said, "the great strength of iSPEX is the measurement philosophy: the establishment of a citizen science network of thousands of enthusiastic volunteers who actively carry out outdoor measurements. In this way, we can collect valuable information about atmospheric particles on locations and/or at times that are not covered by professional equipment. These results are even more accurate than we had hoped, and give rise to further research and development. We are currently investigating to what extent we can extract more information about atmospheric particles from the iSPEX data, like their sizes and compositions. And of course, we want to organize many more measurement days."

Better knowledge of atmospheric particles will improve our understanding of their effects on health, climate and air traffic.

This work has been published in Geophysical Research Letters >>

The Press Release and iSPEX dust maps can be found here >>