In Situ Observations of Interplanetary Dust Variability in the Inner Heliosphere - Malaspina, DM; Szalay, JR; Pokorny, P; Page, B; Bale, SD; Bonnell, JW; de, Wit TD; Goetz, K; Goodrich, K; Harvey, PR; MacDowall, RJ; Pulupa, M (ASTROPHYSICAL JOURNAL, 2020)