AVERAGE DAILY MAGNETIC VARIATION PATTERN AND ITS EQUIVALENT CURRENT PATTERN DETERMINED BY THE IMS ALASKA MERIDIAN CHAIN OF OBSERVATORIES

The average daily magnetic variation pattern and its equivalent current pattern determined by magnetometer data from the IMS Alaska meridian chain of observatories for the period between March 9 and April 271978 are presented in the form of polar plots (magnetic latitude‐MLT coordinates). The corresponding equivalent current pattern shows the so‐called ‘two‐cell’ pattern. Howeverthe computed ionospheric current pattern using the method developed by Kisabeth (1979) has little resemblance to the ‘two‐cell’ patternindicating that the main pattern of the ionospheric currents must be fed by field‐aligned currents. Copyright 1979 by the American Geophysical Union.