Hemispheric and longitudinal asymmetries in CME occurrence according to the corrected SOHO/LASCO CME catalog

The coronal mass ejections (CME) have been observed by the SOHO/LASCO coronagraphs nearly continuously since 1996. These observations have been collected in a database which contains thousands of CMEs whose detailed properties have been studied and discussed in a large number of papers. Here we study the spatial distribution of CMEs in the solar atmosphere. We note on a serious, systematic error in the hemispheric and longitudinal location of the CMEs included in the latter half of the SOHO/LASCO catalog. This error greatly distorts previous results on the spatial location of CMEs at that time. Here we correct the SOHO/LASCO CME catalog for this error and analyze the hemispheric and longitudinal asymmetries in CME occurrence according to the corrected CME database. We show that these results are essentially different from those obtained from the uncorrected catalog. E.g., in the corrected CME catalog the northern hemisphere produces more CMEs than the south in most years in 1997-2007 while the south is clearly more active according to the original catalog. We note on signatures of similar mid-term quasi-periodicities (quasi- biannual oscillations) in CME occurrence that are seen in several other solar and heliospheric parameters. We also find evidence for active longitudes in the CME data, which persist for the entire SOHO interval (solar cycle 23).