Atmospheric SO2 is not only emitted by humans (such this plume in Iraq) but also by volcanoes…
Volcanoes are on watch by satellite observations. This is of high importance as, about 22 volcanoes are active, and 1500 potentially active, around the world.
Optical sensors, such as Sentinel-2, are exploited to track their continuous eruptions (through thermal anomalies at the surface) and to assess the health of plant life and agriculture around the volcanoes. The knowledge of the extent of eruptive deposits is crucial for assessing a volcanic event and any follow-on landslide risk and the size of the affected area.
Furthermore, volcanoes do not only affect the land surfaces but also the atmosphere! They are responsible of continuous gas emissions such as water vapour laced with heavy metals, CO2 – Carbon dioxode, hydrogen sulfide and SO2 – Sulfure dioxide, among many other gases. Cumulative daily and big eruption emissions can be very significant.
The Dutch-Finnish OMI satellite missions provides with high values of atmospheric SO2 measurements. A research team from Michigan Technological University created the first, truly global inventory for volcanic SO2 emissions using OMI data. The publication in Scientific reports mentions that each year volcanoes collectively emit 20 to 25 million tons of SO2 into the atmosphere
The data set will help refine climate and atmospheric chemistry models and provide more insight into human and environmental health risks.
More information on:
- Most active volcanoes on ESA Sentinel-2 watch: http://www.esa.int/Our_Activities/Observing_the_Earth/Earth_s_most_active_volcanoes_on_satellite_watch
First Global Maps of Volcanic Emissions Use OMI NASA Satellite Data: https://www.nasa.gov/feature/goddard/2017/first-global-maps-of-volcanic-emissions-use-nasa-satellite-data
- Carn, S. A. et al. A decade of global volcanic SO2emissions measured from space. Sci. Rep. 7, 44095; doi: 10.1038/srep44095, 2017. here
- WebPage on CO2 – Carbon dioxide here