Impact of Tropospheric Ozone Modulation Due To El Niño on Tides in the MLT. Issue 6 (28th March 2023)

• Record Type: Journal Article
• Authors: Kogure, Masaru; Liu, Huixin; Jin, Hidekatsu
• Is Part Of: Geophysical research letters. Volume 50:Issue 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-03-28
• Subjects: tide -- ozone -- El Niño; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2023GL102790
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: To assess the impacts of the tropospheric ozone modulation due to El Niño on tides, we performed two simulations by using the Ground‐to‐topside Atmosphere Ionosphere model for Aeronomy model: zonally symmetric ozone density and longitudinal ozone variation of an El Niño pattern. Our results show that the ozone modulation strengthens (attenuates) the first symmetric mode of the DW2 (D0 and DW1) tide by ∼+5% (∼−1% and ∼−4%) from ∼20 to ∼100 km altitudes on average. These responses are probably attributed to the tropospheric ozone modulation. These responses are reasonable because both the ozone modulation and these first modes have a peak at the equator. Also, the vertical wavelengths of the first modes are about twice as long as the vertical thickness of the ozone modulation. Our results suggest that the ozone modulation due to El Niño influences the diurnal tides by a few percent because of the ozone modulation spatial structure. Plain Language Summary: Atmospheric absorption of solar radiation generates thermal tidal waves in the Earth's atmosphere, which propagate vertically into ∼100 km and influences the ionosphere and the thermosphere, that is, the edge of the atmosphere. Tides are strongly modulated by the climate and meteorological conditions. Previous studies show that equatorial tides are influenced by El Niño–Southern Oscillation (ENSO) because ENSO controls longitudinal variations of water vapor and rainfall. ENSO also modulates a longitudinal variation of tropospheric ozone density. Although tropospheric ozone is one of the well‐known greenhouse gases, its impact on tides over the equatorial region has not been highlighted. To assess this impact, we perform two simulations: zonally symmetric ozone density and ozone variation of El Niño pattern. This paper found that the ozone modulation of El Niño strengthens a diurnal tide with westward zonal wavenumber 2 (DW2) and attenuates diurnal tides with zonal wavenumber 0 (D0) and westward zonal wavenumber 1 (DW1). The spatial structure of the ozone modulation seems important for those diurnal tidal responses. Key Points: We investigated the impact of the ozone modulation due to El Niño on diurnal tides by using the Ground‐to‐topside Atmosphere Ionosphere model for Aeronomy model The tropospheric ozone modulation can influence the diurnal tides (D0, DW1, and DW2) averaged in one El Niño episode by 1%–5% The spatial structure of the ozone modulation could be important for the impacts on the diurnal tides