Did the solar eclipse of August 11, 1999, show a geomagnetic effect?

The solar eclipse of August 11, 1999, presented good conditions for the stu dy of associated geophysical effects. Ionospheric measurements clearly show a decrease of electron density due to the reduced solar irradiation during the eclipse. However, contrary to claims elsewhere, the decreased conducti vity did not cause an obvious effect in the geomagnetic recordings at the E arth's surface. Recordings of several European geomagnetic observatories an d of a temporary variometer network, set up specially to observe an eclipse effect in detail, have been studied directly and in terms of equivalent cu rrents in the ionosphere. We present the results of these studies and discu ss possible current configurations that might explain the lack of an eclips e effect in geomagnetic recordings.