{"paper":{"title":"A homogeneous aa index: 2. hemispheric asymmetries and the equinoctial variation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"physics.space-ph","authors_text":"Aude Chambodut, Ellen Clarke, Ivan D. Finch, Luke A. Barnard, Mathew J. Owens, Mike Lockwood","submitted_at":"2018-11-24T11:17:19Z","abstract_excerpt":"Paper 1 [Lockwood et al., 2018] generated annual means of a new version of the $aa$ geomagnetic activity index which includes corrections for secular drift in the geographic coordinates of the auroral oval, thereby resolving the difference between the centennial-scale change in the northern and southern hemisphere indices, $aa_N$ and $aa_S$. However, other hemispheric asymmetries in the $aa$ index remain: in particular, the distributions of 3-hourly $aa_N$ and $aa_S$ values are different and the correlation between them is not high on this timescale ($r = 0.66$). In the present paper, a locati"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.09815","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}