2025/03/15 by Zhenghe Xuan, Clarissa Kroll, Robert C. J. Wills · 1 voice
Earth and Planetary Sciences · Environmental Science · #Climate variability and models #Marine and coastal ecosystems #Oceanographic and Atmospheric Processes
paper · doi:10.5194/egusphere-egu25-15963
openalex publication_date 2025/03/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
It is generally thought that the climate responses of El Niño-Southern Oscillation (ENSO) variability and precipitation variability are tightly linked. The reasoning is that ENSO variability leads to sea-surface temperatures and surface heat flux variability, affecting the net-energy input (NEI) and thereby precipitation. We show that equally important are changes in the gross moist stability (GMS), which is the sensitivity of the atmospheric circulation to changes in the NEI. We analyze the variance of vertical velocity in monthly outputs of the Community Earth System Model 2 Large Ensemble. Under the SSP3-7.0 scenario, we find that variance of vertical velocity changes result from the competition of spatially varying responses of NEI variance and GMS. While NEI variance changes are complex and influenced by many mechanisms such as ENSO and radiative feedbacks, GMS increases in the sub-tropics can be explained by the rising tropopause and GMS decreases near the equator can be can be explained by the enhanced heating and moistening of the near-surface eastern equatorial Pacific. Together, these changes have important implications for future changes in precipitation variability in the tropics.