№ 103/2010 from Apr 21, 2010
Researchers at the Institute for Space Sciences at Freie Universität Berlin have, using a specially developed process, taken measurements of the ash cloud that has been paralyzing air traffic worldwide for the past days. Measurements from the ground and the air showed that the ash cloud on Monday, April 19, and Tuesday, April 20, was between two and three kilometers high. The aerosol concentration was considerably higher on Tuesday. In addition, the scientists have been evaluating data from the environmental satellite Envisat that provide information about the height of the volcano eruption.
“The eruption was not continuous, but varied in degree” said Professor Jürgen Fischer, meteorologist at Freie Universität. “The air masses mix the aerosols to different degrees, so there are fluctuations.” The ash cloud was transported toward the east via western air currents.
The space scientists first took measurements from the tower of the Meteorological Institute of Freie Universität in Berlin-Dahlem. On April 20 and 21 they then flew their sampling airplane (a Cessna 207T) south and east of Berlin. Through the vertical ascent and descent, they were able to make statements about the distribution of aerosols in the air. The meteorologists and physicists have developed an instrument, a so-called sun photometer, for measuring the haze in the air. Scientists collect data on the size of the aerosols and their absorption and thus obtain information on the carbon black content in the air.