After 7 year of quiescence, the Hawaiian volcano Mauna Loa began to erupt on Nov. 27. Evaluations of the EOC show the heavy sulfur dioxide (SO2) emissions being carried long distances from Hawaii. The measurement of volcanic emissions allows, among other things, to warn air traffic of volcanic ash clouds that can be dangerous to aircraft engines.
After its last eruption in 1985 it remained quiet, but showing elevated signs of unrest in 2019 with an increase in the inflate rate in the recent years. Lava flows first started from the caldera and later several fissures opened in the Northeast rift zone producing lava fountains and releasing ash and gas.
Huge amounts of sulfur dioxide (SO2) are released at a rate of about 130kt per day rising high into the atmosphere and being transported eastwards over the US. Sentinel-5p/TROPOMI was able to detect the extended volcanic SO2 plume from 28 November onwards. The amount and height of SO2 released from Mauna Loa is analyzed with the UV spectrometer TROPOMI on a daily basis with a spatial resolution of 3.5x5.5 km.
S5p was launched on 13 October 2017 and is operational since March 2018. The SO2 retrieval algorithm and the operational processors were developed by BIRA and DLR, and are integrated in the S5p ground segment running at the DLR Earth Observation Center (EOC) in Oberpfaffenhofen.
SO2 is a natural trace gas in Earth’s atmosphere. The largest source for SO2 in the atmosphere is the burning of fossil fuels by power plants and other industrial facilities. Furthermore volcanic degassing events and eruptions inject SO2 into the atmosphere, ranging from the lower troposphere (passive degassing), as well as high as into the stratosphere (explosive eruptions).
The timely retrieval of SO2 is extremely important for volcanic eruptions which are a major natural hazard, not only to the local environment and populations near large volcanoes but also to aviation.