Aerosols originating from volcanic emissions have an impact on the climate: sulfate and ash particles from volcanic emissions reflect solar radiation, act as cloud condensation and ice nuclei, and modify the radiative properties and lifetime of clouds, and therefore influence the precipitation cycle. These volcanic particles can also have an impact on environmental conditions and could be very dangerous for aircraft in flight.

                            In addition to the routine measurements, further EARLINET observations are devoted to 
                            monitor volcano eruptions. The EARLINET volcanic dataset includes extended 
                            observations related to two different volcanoes in Europe Mt. Etna (2001 and 
                            2002 eruptions), and the Eyjafjallajökull volcano in Iceland (April - May 2010 
                            eruption). This dataset includes also recent events of volcanic eruptions in the 
                            North Pacific region (2008-2010) that emitted sulfuric acid droplets into the upper 
                            troposphere - lower stratosphere (UTLS) height region of the northern hemisphere. 
                            The EARLINET volcanic observations in the UTLS are complemented by the long-term 
                            stratospheric aerosol observations collected in the Stratosphere category.