| 29 Jul 2025
Assessing the Impact of Solar Climate Intervention on Future U.S. Weather Using a Convection-Permitting WRF Model
Abstract. A primary solar climate intervention (SCI) strategy is stratospheric aerosol injection (SAI). SAI would increase the number of small reflective particles (aerosols) in the upper atmosphere to reduce climate warming by reflecting more incoming solar radiation away from Earth. Research on SCI is growing quickly, but no studies to date have examined the impact of SCI on severe storms using a mesoscale weather model. In this study, we develop a novel framework using the convection-permitting (4-km resolution) Weather Research & Forecasting (WRF) model to assess the potential impact of SCI on future convective weather over the contiguous United States (CONUS). We conduct three types of simulations for the March–August 2011 period, during which widespread convective outbreaks occurred across the CONUS: (1) a control simulation driven by ERA-5 reanalysis; (2) a Pseudo-Global Warming (PGW) simulation representing a future with increasing greenhouse gas concentrations but without SCI; and (3) a novel Pseudo-SAI (PSAI) simulation representing a future with SCI. Future climate perturbations applied to the PGW and PSAI boundary conditions are derived from ensemble-mean differences between baseline and future scenarios in Community Earth System Model (CESM) experiments with and without SCI. These perturbations are taken from two CESM projects featuring different scenarios: the Geoengineering Large Ensemble (GLENS) and the Assessing Responses and Impacts of Solar Climate Intervention on the Earth System with Stratospheric Aerosol Injection (ARISE). The PSAI simulation includes an additional aerosol optical depth perturbation to represent the shortwave radiative impact of SAI. This paper presents the novel experimental design and modeling framework, and shares preliminary results that highlight the feasibility and scientific potential of this approach for assessing potential weather-scale impacts of SCI. In particular, we show that global warming leads to an increase in extreme precipitation and more frequent deep convection over the Eastern U.S., both of which can be mitigated by SAI deployment.
This study examined potential effect of SAI on future convective storms over the conterminous United States. The authors utilized global climate model (CESM) simulation results of stratospheric aerosol injection (SAI) to drive the mesoscale regional weather model, WRF. Two sets of ensemble SAI simulation results are used: GLENS and ARISE. The CESM simulated climate change are added to ERA5 data to drive WRF with a horizonal resolution of 4km. The novelty of this study lies in the fact that only a few studies examined the effect of SAI on the thermodynamic environments relevant to weather pattern, and no studies have examined how SAI would affect mesoscale weather using a convective permitting weather model. This study found that SAI could mitigate warming, extreme precipitation, and intense convective activities. I recommend publication after the following comments are addressed:
Lines 35-38: It might not be appropriate to emphasize a single country’s policy in a scientific paper that is not devoted to policy discussion.
Lines 51-52: It would be helpful to briefly describe the experiment design and strategy for GeoMIP and GLENS simulations. This is important because all climate response to SAI would be dependent on the SAI strategy.
Lines 70-77: It’s a bit unconventional to have a ‘result’ figure (Figure. 1) in the Introduction part.
Line 103: What is ‘delta signal’ ? This should be elaborated more.
Lines 104-105: “This results in future thermodynamic environments for the same weather events simulated in the control run.” I don’t quite understand this sentence. Please rephrase.
Line 191: What is the horizonal resolution for ERA5 reanalysis and ARISE and GLENS output? I believe some data interpolation have been done before adding simulated climate change signal to ERA5. This information would be useful.
Line 206: How to modify relative humidity? Please explain
Line 276: Stratospheric aerosol absorb infrared and longwave radiation.
Line 366: What is ‘RR’ in equations (1) and (2)?