JGR–Atmospheres

Arctic cyclone activity is an important component of the local climate, and the frequent occurrence of extreme summer storms has raised widespread scientific interest. In this paper, we investigated the distinctive structural characteristics of intense summer Arctic cyclones by utilizing ERA-Interim reanalysis data and employing a deep learning algorithm for cyclone detection. We found that the northern edge of Eurasia (i.e., the marginal ice zone (MIZ)) and the Alpha Ridge of Arctic Ocean (AR, i.e. central Arctic) are the two most active regions for intense Arctic cyclone activities in summer (from June to September). However, the surface conditions and coupling frequency between surface cyclone and tropopause polar vortices (TPVs) are distinct over these two regions. By further analysis of 100 intense cyclone activities in these two areas, respectively, we found that cyclones in MIZ are often smaller in size but higher in intensity at their maximum intensity, and their life cycles are generally shorter. MIZ cyclones are typically accompanied by a large Eady growth rate and frontal structure in the lower troposphere and their intensification primarily attributed to the thermal-baroclinic process. In contrast, cyclones in AR are more frequently associated with higher potential vorticity (PV) values and pronounced PV downward intrusion from the stratosphere, as well as notable “upper warm-lower cold” structures. The downward intrusion of TPVs and stratosphere vortices contribute to a decrease in the upper and column air mass deficit, leading to the intensification of surface Arctic cyclones in these regions.

The Amazon Basin, which plays a critical role in the carbon and water cycle, is under stress due to changes in climate, agricultural practices, and deforestation. The effects of thermodynamic and microphysical forcing on the strength of thunderstorms in the Basin (75–45°W, 0–15°S) were examined during the pre-monsoon season (mid-August through mid-December), a period with large variations in aerosols, intense convective storms, and plentiful flashes. The analysis used measurements of radar reflectivity, ice water content (IWC), and aerosol type from instruments aboard the CloudSat and CALIPSO satellites, flash rates from the ground-based Sferics Timing and Ranging Network, and total aerosol optical depth (AOD) from a surface network and a meteorological re-analysis. After controlling for convective available potential energy (CAPE), it was found that thunderstorms that developed under dirty (high-AOD) conditions were 1.5 km deeper, had 50% more IWC, and more than two times as many flashes as storms that developed under clean conditions. The sensitivity of flashes to AOD was largest for low values of CAPE where increases of more than a factor of three were observed. The additional ice water indicated that these deeper systems had higher vertical velocities and more condensation nuclei capable of sustaining higher concentrations of water and large hydrometeors in the upper troposphere. Flash rates were also found to be larger during periods when smoke rather than dust was common in the lower troposphere, likely because smoky periods were less stable due to higher values of CAPE and AOD and lower values of mid-tropospheric relative humidity.

In this study, we identified heat index-based spatiotemporally contiguous heatwaves (HI-STHWs) in China based on meteorological observations and Coupled Model Intercomparison Project Phase 6 global climate model simulations. We analyzed the spatiotemporal patterns of changes in HI-STHWs in the past and future and quantitatively attributed these changes to anthropogenic activities. The results show that the duration, severity, average, maximum, and total impacted area of the annual strongest HI-STHWs during the present period of 1991–2014 are 1.77, 2.0, 1.05, 1.14, and 1.89 times the historical period of 1961–1990, respectively. In the fingerprint results, the anthropogenic greenhouse gases (GHG) signal is significantly detected, while the aerosol (AER) and natural (NAT) signals are not. GHG is the primary factor driving the intensification of HI-STHWs, which alone explains about 130%, 122%, 112%, 111%, and 114% of the above changes. The reason for GHG contribution exceeding 100% is that AER might have a negative contribution although nonsignificant. In the future warming climate, anthropogenic activities are projected to lead to more unprecedented HI-STHWs. Under the high emissions scenario of SSP585, by 2100, the annual strongest HI-STHW in China is projected to last almost the whole year and influence 96% regions of China in the most serious day. Meanwhile, its duration and total impacted area are 24.5 [17.2, 31.6] (90% confidence interval) and 107.2 [70, 129.9] times the preindustrial period. However, if the warming level could be limited to 2/1.5°C, those values would be 3.4/5.4 and 8.2/16.2 times smaller than that under the SSP585 scenario by 2100.

Urban morphological change impacts the land surface temperature (LST) through modifying the net radiation, convective heat transfer, evapotranspiration, and heat storage on the ground. It is essential to quantify the contributions of these physical changes on LST changes. In this work, we conduct simulations using a weather research and forecasting model for the Chengdu–Chongqing urban agglomeration to identify causes of LST changes due to urban morphological changes through different morphological parameters: the aspect ratio, building plan area fraction, and average building height. A new method is proposed and used to quantify the contribution of these physical changes on LST changes. The results show as the aspect ratio increases, an increase of the average LST is induced by variations in radiation, and daytime cooling and nighttime warming are induced by variations in heat storage. There is warming associated with an increase in the building plan area fraction, which is mostly caused by a decrease in the efficiency of the long-wave radiant heat emitted from the surface to the atmosphere. We also find that an increase in the average building height enhance the efficiency of convective heat transfer, which results in cooling. These results are important for the management of urban thermal environments.

Wildfire-related aircraft field campaigns frequently offer opportunities to validate remote-sensing retrievals of aerosol properties and other quantities derived from satellite-borne-instrument observations. Satellite instruments often provide regional context-imagery for more sparsely sampled aircraft and surface-based measurements. However, aerosol amount, particle type, aerosol plume height and the associated wind vector products retrieved from the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) instrument have matured sufficiently that these quantities can also contribute substantially to a campaign data set, in regional context. This is especially useful when such measurements are not acquired at all from the suborbital platforms. During NOAA's California Fire Dynamics Experiment (CalFiDE), aircraft operations were coordinated with MISR overpasses on two occasions: for the Rum Creek fire on 30 August 2022, and for the Mosquito fire on 08 September. MISR-retrieved aerosol properties show distinctly different patterns of black and brown smoke particle distributions and inferred plume evolution in the two cases. This paper presents the satellite-retrieved results that complement the field observations, demonstrating what such measurements can offer, and contributing material for detailed fire dynamics and chemistry studies when combined with the CalFiDE suborbital observations and models in continuing studies.

Humic-like substances (HULIS) are a ubiquitous reactive component of atmospheric aerosol. They participate in the formation of secondary organic aerosols via chemical reactions with atmospheric oxidants. Here, we assess the influence of transition metal ions (namely ferric iron, Fe(III)), and nitrate ions (NO3− ${{\text{NO}}_{3}}^{-}$) on the heterogeneous reaction of gaseous NO2 with an aqueous film containing gallic acid (GA) or tannic acid (TA) as proxies for HULIS. Using a vertical wetted wall flow tube technique, the uptake coefficients of gaseous NO2 on GA and TA increased nonlinearly with increasing [Fe(III)], in dark and under light irradiation. However, the combined effect of both ions, Fe(III) and NO3− ${{\text{NO}}_{3}}^{-}$, led to a substantial decrease in NO2 uptake in the dark and under simulated near-UV sunlight irradiation (300 < λ < 400 nm). The lifetime of GA in dilute aqueous phase, which corresponds to cloud water, due to reaction with NO2 would be 6 hr during both nighttime and daytime. However, the lifetime of GA in aerosol particles which contain both ions, that is, Fe(III) and NO3− ${{\text{NO}}_{3}}^{-}$, would increase to 27 hr during nighttime and 11 days and 6 hr due to light-induced reaction with NO2. Also, we observed, using Fourier transform ion cyclotron resonance mass spectrometry, the formation of nitrocatechols compounds (e.g., methyl-nitrocatechol), which contribute to brown carbon. Compounds with reduced functional groups such as amines were also observed in the presence of iron and nitrate ions in the dark and under irradiation, indicating that Fe(III) and NO3− ${{\text{NO}}_{3}}^{-}$, can influence the kinetics and product distribution in deliquescent aerosol particles.

The roles of the Tibetan Plateau (TP) and Yunnan-Guizhou Plateau (YGP) in regional precipitation extremes over the Sichuan Basin (SCB) in summer under specific circulation background remain unclear. This study quantifies the impact of TP or YGP on the regional extreme precipitation event (REPE) which occurred during 04:00 Beijing time (BJT) on 11 August to 03:00 BJT on 13 August 2020 with a rainfall center located in the western SCB based on numerical experiments. Results show that the accumulated precipitation regionally averaged over the western SCB during the REPE can be reduced by 84% (51%) when the TP (YGP) is absent, and the decreased precipitation is mainly caused by the reduced stratus precipitation. Mechanism analysis indicates that relative to the control experiment including the TP and YGP, the absence of TP or YGP leads to reduced temperature over the SCB induced by anomalous cold advection from the upstream regions where the terrains are removed, and further results in much more stable stratification and thereafter weakens the ascending motions and reduces the stratus precipitation over the western SCB. On the other hand, the absence of TP or YGP induces an anomalous anti-cyclone at 850 hPa over SCB, which further weakens both the uplift effect of terrain on airflow along the windward slope and water vapor transport over the western SCB and thereafter reduces the precipitation over this region. This study deepens the understanding of the topographic effect on regional extreme precipitation over SCB in summer from the thermodynamic and dynamic processes.

This study focuses on a new compounding concern, the sudden turn from drought to flood (STDF), that is becoming increasingly prominent. This study investigates the long-term trends and variability of STDFs in China during 1961–2020. The findings indicate that STDFs are prevalent in north and northeast China, and the Yangtze River Delta (YRD). The probability of a drought being followed by a severe flood is approaching 35% in northern and northeastern China. Since 1961, the number of STDFs in China has increased at a rate of average 2.8 events per decade. This increase mainly has occurred in late spring and early summer. The likelihood that a drought being followed by a significant pluvial is also increasing. The increasing STDF in northern China is mainly attributable to the increasing flood frequency and volatility of precipitation. Changes in the STDF trend is more dependent on the drought frequency in the YRD.

The spring warm pool (SWP) in the South China Sea (SCS) is a region west of Luzon Island with a sea surface temperature nearing 30°C in late spring, significantly higher than the surrounding waters. Understanding its formation aids in reliable prediction of the summer monsoon onset in the SCS. The current explanation for the SWP formation is the wake effect, which claims that the orographic blocking of Luzon Island forms a wake zone west of Luzon Island and so considerably reduces sea surface latent heat (LH) flux release during the winter monsoon season in comparison to adjacent waters. In this study, we enhance this explanation by incorporating the foehn clearance effect. Our statistical analysis indicates that the SWP evolution is strongly associated with frequent foehn clearance west of Luzon Island and that, in the SWP domain relative to its adjacent domains, the increase of surface short-wave (SW) radiation induced by the foehn clearance effect is almost equal to the decrease of surface LH loss resulting from the wake effect. The ocean mixed layer heat budget analyses not only confirm that the zonal difference of surface heat flux dominates the SWP formation, but also demonstrate that this zonal difference is largely contributed by the zonal difference of SW radiation caused by the foehn clearance effect. Furthermore, sensitivity assessments demonstrate that the SWP would not emerge if the foehn clearance effect was excluded, indicating that both the wake effect and the foehn clearance effect contribute jointly to the SWP formation.

Recent studies have shown that the dust emission efficiency (E d ) of some soil surfaces undergoes changes with wind speed and that such changes are related to soil properties. Through wind tunnel experiments, we investigate the comprehensive effect of soil particle size composition (PSC) (both minimally and fully dispersed) and friction wind speed (u *) on E d . Results show that E d initially increases and then decreases as soil texture changes from fine to coarse, with intermediate-textured soils having the highest E d and the strongest dust emission ability. The ratio of silt to sand in soil is an index suitable for reflecting the influence of soil texture on E d . The PSC of soil dry aggregate is a factor that directly determines E d . With increasing u *, E d tends to increase for coarse- and intermediate-textured soils but not for fine-textured soil, supporting the view that E d is influenced by u * and that the influence is related to soil PSC. Despite the fitting power function equations between E d and u * for some soils failing to pass the significance test in this study, the substantial influence of soil texture on the power exponents implies potential for establishing an equation capable of expressing the comprehensive effect of soil texture and u * on E d .

Water vapor and cirrus clouds in the tropical tropopause layer (TTL) are important for the climate and are largely controlled by temperature in the TTL. On interannual timescales, both stratospheric and tropospheric modes of the large-scale variability could affect temperatures in the TTL. Here multiple linear regression (MLR) is used to investigate explained variance in the cold point tropopause temperature (CPT), cold point tropopause height (CPZ), 83 hPa water vapor (WV83), 83 hPa ozone (O383), and total cirrus cloud fraction with cloud base (TTLCCF) and top (ALLCF) above 14.5 km, all averaged over 15°S-15°N. Predictors of the MLR are a set of stratospheric and tropospheric large-scale modes of variability. The MLR explains significant variance in CPT (76%), CPZ (78%), WV83 (65%), O383 (62%), TTLCCF (52%), and ALLCF (36%). The interannual variability of CPT and WV83 is dominated by stratospheric processes associated with the Quasi-Biennial Oscillation (QBO) and Brewer-Dobson Circulation (BDC), whereas the variability of CPZ, O383, TTLCCF and ALLCF is also controlled by 500 hPa temperature (T500). Residual variability in CPT and CPZ not captured by the MLR are further significantly correlated to stratospheric temperature. It is shown that the portion of the BDC's shallow branch missed by the eddy heat flux based BDC index contributes significant amounts of the explained variances.

The water vapor transport associated with latent heat flux (LE) in the planetary boundary layer (PBL) is critical for the atmospheric hydrological cycle, radiation balance, and cloud formation. The spatiotemporal variability of LE and water vapor mixing ratio (r v ) are poorly understood due to the scale-dependent and nonlinear atmospheric transport responses to land surface heterogeneity. Here, airborne in situ measurements with the wavelet technique are utilized to investigate scale-dependent relationships among LE, vertical velocity (w) variance (σw2 ${\sigma }_{w}^{2}$), and r v variance (σH2O2 ${\sigma }_{\mathrm{H}2\mathrm{O}}^{2}$) over a heterogeneous surface during the Chequamegon Heterogeneous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors 2019 (CHEESEHEAD19) field campaign. Our findings reveal distinct scale distributions of LE, σw2 ${\sigma }_{w}^{2}$, and σH2O2 ${\sigma }_{\mathrm{H}2\mathrm{O}}^{2}$ at 100 m height, with a majority scale range of 120 m–4 km in LE, 32 m–2 km in σw2 ${\sigma }_{w}^{2}$, and 200 m–8 km in σH2O2 ${\sigma }_{\mathrm{H}2\mathrm{O}}^{2}$. The scales are classified into three scale ranges, the turbulent scale (8–200 m), large-eddy scale (200 m–2 km), and mesoscale (2–8 km) to evaluate scale-resolved LE contributed by σw2 ${\sigma }_{w}^{2}$ and σH2O2 ${\sigma }_{\mathrm{H}2\mathrm{O}}^{2}$. The large-eddy scale in PBL contributes over 70% of the monthly mean total LE with equal parts (50%) of contributions from σw2 ${\sigma }_{w}^{2}$ and σH2O2 ${\sigma }_{\mathrm{H}2\mathrm{O}}^{2}$. The monthly temporal variations mainly come from the first two major contributing classified scales in LE, σw2 ${\sigma }_{w}^{2}$, and σH2O2 ${\sigma }_{\mathrm{H}2\mathrm{O}}^{2}$. These results confirm the dominant role of the large-eddy scale in the PBL in the vertical moisture transport from the surface to the PBL, while the mesoscale is shown to contribute an additional ∼20%. This analysis complements published scale-dependent LE variations, which lack detailed scale-dependent vertical velocity and moisture information.

Acidity is an essential characteristic of aerosol particles that influences chemical and physical properties. Aerosol particles in tropical Asia, such as Singapore, have been reported as highly acidic due to intense anthropogenic sulfur emissions. At the same time, the region has also been experiencing wildfire over tropical peatlands, which is recognized as an intense source of NH3. Here, we investigated the role of NH3 from wildfire on aerosol particles in Singapore by employing the aerosol mass spectrometric technique. The observation was conducted both during wildfire haze (2015 October and 2019 September–October) and non-haze (2018 October and 2019 April) periods. The observation result demonstrated that inorganic ionic species in Singapore were neutralized by NH4 + during the haze periods. Namely, the degree of neutralization of aerosol particles (i.e., measured NH4 + concentration/predicted NH4 + concentration by assuming that NH4 + fully neutralized SO4 2−, NO3 −, and Cl−) was lower than 0.77during the non-haze periods. On the other hand, the corresponding values were higher than 0.93 during the haze periods. In addition, NO3 − concentration during the daytime of the haze period in 2015 was higher than that in other observation periods. A thermodynamic model calculation suggested that the regime shifts from the “NH3 sensitive region” to the “NH3 and HNO3 sensitive region” or “HNO3 sensitive region” might have occurred during the haze period. In the future, continuous monitoring of both gas- and particle-phase inorganic chemical species will need to be conducted to investigate the impact of wildfire haze on atmospheric chemical processes in more detail.

Mineral dust aerosols play an important role in Earth's climate through interactions with incoming solar radiation, clouds, and the atmosphere. However, dust sources in the Horn of Africa (HoA) and controls on their activation are poorly documented. Here, we use fifteen-minute Meteosat Second Generation Spinning Enhanced Visible and Infrared Imager dust index images to identify HoA dust source areas and to quantify their activation frequency in 1° × 1° resolution from 2006 to 2010. Around half of all recorded dust events occur in boreal summer, mostly between 8:00 and 16:00 local time. They are driven by meso- to regional scale meteorological mechanisms including the breakdown of the nocturnal low-level jets, land-sea breezes, and haboobs. By far the most dust-active region in the HoA is the Afar Triangle (>77% of all recorded dust events) which features the Afar and Danakil depressions and is fed by the Awash River. Despite experiencing strong and persistent southwest summer monsoon winds, dust activation on the Somali Peninsula is less significant. A composite of our map with data for North Africa and westernmost Asia shows that the HoA is a striking latitudinal anomaly with dust activation extending deep into the equatorial belt. Our data also reveal that dust activation is unusually seasonal with ∼40% of events occurring in June and July. Our findings show that aridity and mean wind strength alone are poor predictors of dust activation and underscore the strong control exerted by the availability of readily deflated unconsolidated riverine and lacustrine sediments.

Based on a 6-year long record (2014–2020) of the isotopic composition of rain (δ18Op) at Réunion Island (55°E, 22°S), in the South-West Indian Ocean, this study shows that the annual isotopic composition of precipitation in this region is strongly controlled by the number of cyclones, the number of best-track days, and the proportion of cyclonic rain during the year. Our results support the use of δ18Op in annual-resolved tropical climate archives as a reliable proxy of past cyclone frequency. The influence of the proportion of cyclonic rain on the annual isotopic composition arises from the systematically more depleted precipitation and water vapor during cyclonic events than during less organized convective systems. The analysis of the daily to hourly isotopic composition of water vapor (δ18Ov) during low-pressure systems and the reproduction of daily δ18Ov observations by AGCMs with a global medium to coarse resolution (LMDZ-iso and ECHAM6-wiso) suggest that during cyclonic periods the stronger depletion mainly arises from both enhanced large-scale precipitation and water vapor-rain interactions under humid conditions.

There is an urgent need to enhance climate projections for Central Equatorial Africa (CEA), given the region's high vulnerability to climatic hazards and its economy's heavy dependence on climate-sensitive sectors. This study aims to evaluate the performance of the regional earth system model ROM, composed of the atmosphere-only regional climate model (RCM) REMO coupled with the global Max Planck Institute for Meteorology Ocean Model (MPIOM), in reproducing the precipitation climatology over CEA. ROM results are compared to those of REMO in two sets of experiments, one driven by the ERA-Interim reanalysis and the other by the MPI-ESM-LR earth system model (ESM), both at ∼25-km horizontal resolution. Results show that ocean coupling improves rainfall climatology thanks to a better representation of the physical processes and mechanisms underlying the rainfall system. In particular, an improved sea surface temperature (SST) results in a more realistic simulation of land-atmosphere-ocean interactions, and subsequently the atmospheric baroclinicity. Specifically, the coupling reduces the positive SST bias inherited by the driving ESM across the entire Guinea Gulf and Benguela-Angola coastal seas. This leads to better simulated land-ocean thermal and pressure contrasts. Improvements in land-ocean contrasts, in turn, enhance the representation of the regional atmospheric circulation, and thus precipitation. Interestingly, the coupling is more beneficial when ROM is driven by the ESM than the reanalysis. This study emphasizes the advantage of dynamically downscaling ESMs using regional earth system models rather than atmosphere-only RCMs, with the potential to enhance confidence in future climate projections.

This study explores the impact of rising CO2 levels on the Atlantic meridional overturning circulation's (AMOC) interdecadal variability within the context of the Last Glacial Maximum (LGM) background climate. Under heightened CO2 concentrations, the AMOC interdecadal variability intensifies dramatically, which is very different from the future warming case that shows a weakening of AMOC interdecadal variability in response to increased CO2 concentration. This unexpected phenomenon primarily results from the extensive retreat of sea ice, which exposes a larger portion of the ocean surface to efficiently feel the heat flux fluctuations from atmospheric processes. These findings underscore the significance of background climate conditions in shaping AMOC responses to increased CO2 and emphasize the necessity of considering these nuances to develop a more accurate understanding of AMOC dynamics in an evolving climate.

Dansgaard-Oeschger (D-O) climate variability during the last glaciation was first evidenced in ice cores and marine sediments, and is also recorded in various terrestrial paleoclimate archives in Europe. The relative synchronicity across Greenland, the North Atlantic and Europe implies a tight and fast coupling between those regions, most probably effectuated by an atmospheric transmission mechanism. In this study, we investigated the atmospheric changes during Greenland interstadial (GI) and stadial (GS) phases based on regional climate model simulations using two specific periods, GI-10 and GS-9 both around 40 ka, as boundary conditions. Our simulations accurately capture the changes in temperature and precipitation as reconstructed by the available proxy data. Moreover, the simulations depict an intensified and southward shifted eddy-driven jet during the stadial period. Ultimately, this affects the near-surface circulation toward more southwesterly and cyclonic flow in western Europe during the stadial period, explaining much of the seasonal climate variability recorded by the proxy data, including oxygen isotopes, at the considered proxy sites.

Understanding the present and future features of atmospheric rivers (ARs) is critical for effective disaster prevention and mitigation efforts. This study comprehensively assesses the performance of ARs in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) models on both seasonal and interannual timescales within the historical period and investigates the future projection of ARs under different emission scenarios on a global scale. The multi-model mean results obtained using the PanLu detection algorithm consistently exhibit agreement with the observational AR climatology and capture interannual fluctuations as well as the relationships with large-scale drivers. The future projections reveal increased AR frequency, intensity, duration, and spatial extent and decreased landfall intervals with regional variations and seasonal fluctuations. Besides, the AR frequency increase will accelerate around the middle of the century, attributed to a non-linear rise in surface temperature. Furthermore, mid-latitude ARs are gradually shifting toward higher latitudes in both hemispheres under SSP585, with Greenland experiencing a substantial increase in AR frequency and AR-induced precipitation. The hydrological implications arising from more frequent ARs are manifested more prominently in AR-induced heavy precipitation (HP), with regions historically characterized by lower AR occurrence also receiving a higher percentage of precipitation from ARs. At last, an incremental decomposition highlights the dominant role of thermal effects and relatively limited contributions from dynamical effects in AR changes. Besides, the interplay between regionally divergent temperature amplification results in different dynamically driven AR responses across the globe.

Carbonate radical anion (CO3.− ${\mathrm{C}{\mathrm{O}}_{3}}^{.-}$) is generally overlooked in atmospheric chemistry. Our recent work emphasizes the important role of carbonate radicals produced on mineral dust surfaces in fast sulfate production under solar irradiation in the presence of CO2 at specifically low RH and light intensity. Yet so far how CO3.− ${\mathrm{C}{\mathrm{O}}_{3}}^{.-}$ involves and affects secondary sulfate production under diverse RH, light intensity, and complex constituent matrix remains unknown, which essentially limits our comprehensive knowledge of CO3.− ${\mathrm{C}{\mathrm{O}}_{3}}^{.-}$initiated SO2 oxidation scheme in the atmosphere. Herein, we explored the heterogeneous SO2 oxidation over both model and authentic dust and clays in the presence of CO2 at atmospheric relevant RHs and light intensities. Interestingly, we observe that CO2 promotes sulfate yield over authentic dust and clays at atmospheric-relevant RH and light intensity. This observation relates to the favorable kinetic between SO2 oxidation and CO3.− ${\mathrm{C}{\mathrm{O}}_{3}}^{.-}$ while auto-quenching of these radical ions is largely minimized due to the sufficient sites of crustal constituents. Furthermore, employing a suite of authentic dust and machine learning strategies, we evaluated the relative importance of each constituent within airborne minerals or clays as well as environmental conditions including relative humidity, light intensity, and CO2 concentration in affecting SO2 uptake capability. On this basis, sulfate formation mediated by dust-driven pathway, accounting for nearly ∼20.9% of overall contribution by the end of this century during some pollution episodes, even higher than gas-phase ·OH $\cdot \text{OH}$ (∼16.9%), will be increased by 163% if CO2-initiated SO2 oxidation scheme is incorporated.