(NECN: Joe Joyce) - The eruption of Iceland's Eyjafjallajokull volcano shot an ash plume about five miles into the sky, close to the stratosphere.
Since the eruption, the ash has stayed in the lower troposphere. Eventually, planes will be able to fly over the ash cloud as it continues to sink -- it will not be great for health.
Had the ash continued to move into the stratosphere, it could have resulted in a global cooling effect with eruptions that might span weeks or even months. In the 1700s, an Icelandic volcanic eruption helped to allow for parts of Earth to fall into a mini-Ice Age.
The jetstream is not expected to make significant movement until next weekend, at which time it should shift the ash cloud farther north.