Abstract The Community Earth System Model (CESM) Whole Atmosphere Community Climate Model with thermosphere‐ionosphere eXtension (WACCM‐X) is used to investigate how the ionosphere‐thermosphere response to a May 2024‐like geomagnetic storm changes with increasing greenhouse gases. Coupled CESM(WACCM‐X) simulations are first performed following the Coupled Model Intercomparison Project Phase 6 Shared Socioeconomic Pathway 5–8.5 from 2000 to 2090. The May 2024 geomagnetic superstorm is then simulated in 2016, 2040, 2061, and 2084, corresponding to surface CO2 ${\text{CO}}{2}$ levels of 403, 500, 652, and 918 ppmv, respectively. The CESM(WACCM‐X) simulations indicate that increasing levels of CO2 ${\text{CO}}{2}$ weakens the absolute neutral density response at 350 km. However, the relative response is increased with increasing levels of CO2 ${\text{CO}}{2}$, which is partly due to the decrease in the background neutral density. Due to a weaker response in thermosphere composition and meridional neutral winds, the ionospheric response in absolute terms also weakens with increasing levels of CO2 ${\text{CO}}{2}$.
Observations from the Little Bunker
Last updated: August 18, 2025 04:13 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year