Relationship between auroral electrojet and Pc5 ULF waves

Applying a new data visualization technique to magnetic field observations from the Greenland west coast array we observe that Pc5 wave power spatial/ temporal variations in the morning/pre-noon sector are closely related to t he location and intensity of the auroral electrojet. This effect is not tak en into account by existing theories of ULF Pc5 waves, but it could be sign ificant for the development of more adequate models. Consideration of the m ost evident interpretation schemes shows that there is no simple explanatio n of this effect. An adequate interpretation may require a substantial revi sion or augmentation of existing Pc5 models. (C) 2001 Published by Elsevier Science Ltd.