Passive microwave remote sensing of Plinian eruption due to the Grímsvötn Icelandic volcano

The sub-glacial Plinian explosive eruption of the Grímsvötn volcano on May 2011 is analyzed and quantitatively interpreted by using satellite passive microwave observations. The prevailing southerly winds stretched the erupted plume toward the Artic pole, thus preventing the ash cloud to move towards continental Europe and threatening the airline traffic (differently from the less explosive Eyjafjöll eruption on April and May 2010). Satellite microwave radiometric imagery is investigated to show the potential contribution and limitations to the understanding and modeling of explosive volcanic ash eruptions. We show the correlation of spaceborne microwave brightness temperatures with the ash columnar content derived from ground-based C-band radar retrievals. Microphysical sensitivity of satellite microwave brightness temperatures to the eruption plume fine and coarse ash suggests their exploitation in synergy with satellite thermal infrared radiometer and ground-based microwave radar observations.