On geomagnetic variations during the August-September storms of 1859

During the Carrington storm on September 2 (05-07 UT) the observatories were well inside the auroral oval and the disturbances (mostly positive) registered were connected with eastward flowing auroral electrojets and field-aligned currents. No magnetic signatures of the ring-current can be seen in the observations. However, simultaneous magnetic variations at the Colaba observatory (magn. lat. 10.5°N) near the Equator showed a deep depression (about −1600 nT) in H mostly due to ring-current effects.