VOLCANIC CLOUDS: Alaska's Mt. Redoubt volcano has erupted no fewer than 19 times since March 22nd, and several of the larger blasts have hurled plumes of ash and gas into the lower stratosphere. The GOME-2 (Global Ozone Monitoring Experiment) sensor onboard Europe's MetOp-A satellite has been tracking Redoubt's sulfur dioxide emissions, colored red in this March 26th SO2 column density map:
The animation begins on March 25th and ends on the 28th. One cloud has just crossed North America en route to the Atlantic Ocean and Europe. A second cloud is leaving Alaska on the same east-west track. The last time an Alaskan volcano blew its top (Kasatochi in 2008), clouds like these caused fantastic sunsets around the northern hemisphere. More could be in the offing. If you live along the SO2 ground track, keep an eye on the twilight sky for signs of Redoubt--and stay tuned for updates.