The eruption produces volcanic smoke and ash that moves on the wind. To estimate the direction of movement, please refer to the following wind maps.
A meteorological satellite is mainly used for observing atmosphereic phenomena, but can also be used for observing other phenomena. For the eruption of volcanoes, for example, the satellite can observe the extension of volcanic plume on visible imagery, and the increase of surface temperature on ifrared imagery.
Here we study an example of an eruption of Mt. Pinatubo, Luzon Island, the Philippines, that started on 13:42 (local time) on June 15, 1991. The eruption of Mt. Pinatubo continued for 9 hours and a large amount of ash was ejected during the eruption. The visible image below is taken around 13:42:10 (local time), just after the eruption. Mt. Pinatubo is located at the center of the image, and you can see fumes of the volcano like a mushrooom, and the shadow of the fume cast on the cloud top.
The visible image of Himawari-4 just after the eruption of Mt. Pinatubo (around 13:42:10 local time). The center is the location of Mt. Pinatubo (N 15.13, E120.35), and the range of the image is 480km for east-west, and 360km for north-south.
The spiral cloud on this image is Typhoon 199105 (YUNYA). This event was an unfortunate coincidence of volcanic eruption and the approach of a typhoon. The ash from eruption was mixed with rainfall from the typhoon, and heavy ash that absorbed the water fell down extensively across Luzon Island. The roof of houses was collapsed by the weight of the ash, and this is regarded as one of important factors leading to many victims.
The eruption of Mt. Pinatubo was thought to be one of the largest in the 20th century, and a large amount of ejected aerosols reached the stratosphere and stayed there for a long period of time. This event caused the decrease of temperature in the lower atmosphere, and gave a valuable example for assessing the effect of aerosols in the context of global warming.
Case studies of past volcanic eruptions are provided in the following pages.