Optical and particle measurements made from the Isis 2 spacecraft during August 1972 geomagnetic storm are reported for August 4, 5, and 6. Soon after the two sudden commencements which initiated the storm on August 4 a bright optical aurora was detected in the range of 60¿--65¿ invariant in the dawn sector. On the duskside, only weak aurora was present from 61¿ to 71¿, but there was an 18-kR SAR (stable auroral red) arc at 61¿ invariant confined to 1¿ of latitude range and located at the poleward boundary of a broader region of 150-keV isotropic protons. On the morning side, thermally excited 6300-¿ emission was apparent only below 55¿ invariant, much weaker, and much more widespread. As the storm progressed, this mid-latitude emission weakened, but following the major sc at 2054 on August 4 a sharply defined 6300-¿ feature was observed at 27¿ invariant at the inner of two plasmaphere shells observed by Brace et al. (1974). It is concluded that at no time during the storm was 'classical' SAR arc generated, driven by a symmetrical ring current. Instead, an asymmetrical SAR arc generated by inward diffusion of protons during ring current formation was detected, as well as widespread thermal emission arising from unidentified magnetospheric heating processes.