# An initial ULF wave index derived from 2 years of Swarm observations

> Research article (Annales Geophysicae, 2018) · cited 14× · AI/ML

**Wikidata**: [openalex:W2791640955](https://www.wikidata.org/wiki/openalex:W2791640955)  
**Source**: https://4ort.xyz/entity/an-initial-ulf-wave-index-derived-from-2-years-of-swarm-observations