Statistical Analysis of Equatorial Plasma Bubbles Climatology and Multi‐Day Periodicity Using GOLD Observations. Issue 8 (26th April 2023)

• Record Type: Journal Article
• Authors: Aa, Ercha; Zhang, Shun‐Rong; Liu, Guiping; Eastes, Richard W.; Wang, Wenbin; Karan, Deepak K.; Qian, Liying; Coster, Anthea J.; Erickson, Philip J.; Derghazarian, Sevag
• Is Part Of: Geophysical research letters. Volume 50:Issue 8(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-04-26
• Subjects: equatorial plasma bubbles -- GOLD nighttime image -- day‐to‐day variability -- planetary waves; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2023GL103510
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: This study develops a new Bubble Index to quantify the intensity of 2‐D postsunset equatorial plasma bubbles (EPBs) in the American/Atlantic sector, using Global‐scale Observations of the Limb and Disk (GOLD) nighttime data. A climatology and day‐to‐day variability analysis of EPBs is conducted based on the newly‐derived Bubble Index with the following results: (a) EPBs show considerable seasonal and solar activity dependence, with stronger (weaker) intensity around December (June) solstice and high (low) solar activity years. (b) EPBs exhibit opposite geomagnetic activity dependencies during different storm phases: EPBs are intensified concurrently with an increasing Kp, but are suppressed with high Kp occurring 3–6 hr earlier. (c) For the first time, we found that EPBs' day‐to‐day variation exhibited quasi‐3‐day and quasi‐6‐day periods. A coordinated analysis of Ionospheric Connection Explorer (ICON) winds and ionosonde data suggests that this multi‐day periodicity was related to the planetary wave modulation through the wind‐driven dynamo. Plain Language Summary: Equatorial plasma bubbles (EPBs) are plasma density depletions that frequently occur in the nighttime equatorial and low latitude ionosphere, which are well‐known for imposing significant space weather effects on navigation and communication systems. This study develops a novel Bubble Index to quantify EPBs' activity, using the Global‐scale Observations of the Limb and Disk (GOLD) nighttime data. Based on this new Bubble Index, a climatology study and day‐to‐day variability analysis of GOLD‐captured EPBs were conducted. The EPBs' seasonal variation and solar and geomagnetic activity dependence were revealed and examined. Moreover, for the first time, we found the day‐to‐day variation of EPBs' intensity showed quasi‐3‐day and quasi‐6‐day periods. A coordinated analysis of neutral wind and ionosonde measurements suggests that this multi‐day periodicity was likely caused by planetary wave modulation via the wind‐driven dynamo. These new results shed new light on the day‐to‐day variability of the ionosphere and its possible connection with atmospheric waves. Key Points: A new Bubble Index is developed to quantify 2‐D EPBs' intensity over the American/Atlantic sector using GOLD nighttime disk image data A first‐time statistical analysis of GOLD data shows that equatorial plasma bubbles (EPBs) have opposite geomagnetic activity dependencies during different storm phases EPBs' intensity exhibits ∼3‐ and ∼6‐day periodicity, coinciding with planetary waves feature observed in atmospheric winds and hmF2