Substantial cooling effect from aerosol-induced increase in tropical marine cloud cover

Nature Geoscience, Journal Year: 2024, Volume and Issue: 17(5), P. 404 - 410

Published: April 11, 2024

Abstract With global warming currently standing at approximately +1.2 °C since pre-industrial times, climate change is a pressing issue. Marine cloud brightening one proposed method to tackle through injecting aerosols into marine clouds enhance their reflectivity and thereby planetary albedo. However, because it unclear how influence clouds, especially cover, both projections the effectiveness of remain uncertain. Here we use satellite observations volcanic eruptions in Hawaii quantify aerosol fingerprint on tropical clouds. We observe large enhancement reflected sunlight, mainly due an aerosol-induced increase cover. This observed strong negative forcing suggests that current level driven by weaker net radiative than previously thought, arising from competing effects greenhouse gases aerosols. implies greater sensitivity Earth’s therefore larger response rising gas concentrations reductions atmospheric air quality measures. our findings also indicate mitigation via plausible most effective humid stable conditions tropics where solar radiation strong.

Language: Английский

---

Large contribution of fossil-derived components to aqueous secondary organic aerosols in China

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 31, 2022

Incomplete understanding of the sources secondary organic aerosol (SOA) leads to large uncertainty in both air quality management and climate change assessment. Chemical reactions occurring atmospheric aqueous phase represent an important source SOA mass, yet, effects anthropogenic emissions on (aqSOA) are not well constrained. Here we use compound-specific dual-carbon isotopic fingerprints (δ13C Δ14C) dominant aqSOA molecules, such as oxalic acid, track precursor formation mechanisms aqSOA. Substantial stable carbon isotope fractionation molecules provides robust evidence for extensive aqueous-phase processing. Contrary paradigm that these compounds largely biogenic, radiocarbon-based apportionments show fossil precursors produced over one-half molecules. Large fractions fossil-derived contribute substantially total water-soluble load hence impact projections radiative forcing. Our findings reveal importance with quality.

Language: Английский

---

Rapid night-time nanoparticle growth in Delhi driven by biomass-burning emissions

Nature Geoscience, Journal Year: 2023, Volume and Issue: 16(3), P. 224 - 230

Published: March 1, 2023

Language: Английский

---

Hydrogen peroxide serves as pivotal fountainhead for aerosol aqueous sulfate formation from a global perspective

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 30, 2024

Abstract Traditional atmospheric chemistry posits that sulfur dioxide (SO 2 ) can be oxidized to sulfate 4 2– through aqueous-phase reactions in clouds and gas-phase oxidation. Despite adequate knowledge of traditional mechanisms, several studies have highlighted the potential for SO oxidation within aerosol water. Given widespread presence tropospheric aerosols, 2− production water could a pervasive global impact. Here, we quantify contributions aqueous pathways formation based on GEOS-Chem simulations subsequent theoretical calculations. Hydrogen peroxide (H O significantly influences continental regions both horizontally vertically. Over past two decades, shifts typical cities reveal an intriguing trend: despite reductions emissions, increased capacities, like rising H levels, prevent steady decline concentrations. Abating oxidants would facilitate benefit reduction positive feedback mitigation.

Language: Английский

---

Particle phase state and aerosol liquid water greatly impact secondary aerosol formation: insights into phase transition and its role in haze events

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(4), P. 2399 - 2414

Published: Feb. 26, 2024

Abstract. The particle phase state is crucial for reactive gas uptake, heterogeneous, and multiphase chemical reactions, thereby impacting secondary aerosol formation. This study provides valuable insights into the significance of particle-phase transition liquid water (ALW) in mass growth during winter. Our findings reveal that particles predominantly exist a semi-solid or solid clean winter days with ambient relative humidity (RH) below 30 %. However, non-liquid to occurs when ALW fraction exceeds 15 % (dry mass) at RH thresholds 40 %–60 During haze episodes, transformation rates sulfate nitrate aerosols rapidly increase through increased by 48 11 %, respectively, resulting noticeable increases inorganic (SIA). presence abundant ALW, favored elevated higher proportion SIA, facilitates partitioning water-soluble compounds from phase, as well heterogeneous aqueous processes particles. leads substantial formation organic oxidation. Consequently, overall hygroscopicity parameters exhibit enhancement, mean value 23 These results highlight key factor initiating positive feedback loops between episodes over North China Plain. Accurate predictions necessitate explicit consideration transport models.

Language: Английский

---

Analysis of aerosol liquid water content and its role in visibility reduction in Delhi

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 867, P. 161484 - 161484

Published: Jan. 10, 2023

Language: Английский

---

Mist cannon trucks can exacerbate the formation of water-soluble organic aerosol and PM_2.5 pollution in the road environment

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(12), P. 6775 - 6788

Published: June 20, 2023

Abstract. Mist cannon trucks have been widely applied in megacities China to reduce the road dust, since they are considered be more water saving and efficient than traditional sprinkling trucks. However, their effect on formation of water-soluble organic compounds pollution control fine particles (PM2.5) remains unknown. We characterized variations chemical compositions PM2.5 collected sides during simulated operations mist truck via Fourier transform ion cyclotron resonance mass spectrometry chromatography. The concentrations carbon showed a significant increase (62 %–70 %) after air spraying. Furthermore, we found that compounds, particularly nitrates, increased significantly interactions reactive gas-phase organics, atmospheric oxidants aerosol liquid spraying, although spraying had better suppressing dust ground aspersion. Moreover, segment where passed by was promoted, with an up 13 % concentration 25–35 min, average. Thus, application potentially worsens environment through levels production large number PM2.5. overall results provide not only valuable insights processes associated but also management strategies regulate operation China.

Language: Английский

---

Enhanced Nitrate Fraction: Enabling Urban Aerosol Particles to Remain in a Liquid State at Reduced Relative Humidity

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(21)

Published: Nov. 6, 2023

Abstract Nitrate has become the primary inorganic compound in urban aerosol particles, but its effects on particle phase state, which is crucial multiphase chemistry, remains largely unknown. Herein, rebound measurements were conducted to explore relationship between liquid–phase–transition threshold relative humidity (RH ) and compounds mass fraction dry particles (F inorg ). Results revealed negative correlations RH F , with more nitrate leading lower . Even < 20%, ∼50% remained non‐solid state. Taking Beijing as an example, decreases observed from 64% 2015 below 53% nowadays during moderate‐pollution periods (PM 2.5 = 35–75 μg/m 3 due enhanced fraction. This allowed exist liquid state at RH, consequently, kinetic limitation by bulk diffusion nitrate‐dominated might be negligible, making them key seeds for secondary formation through reactions.

Language: Английский

---

Is a more physical representation of aerosol chemistry needed for fog forecasting?

Quarterly Journal of the Royal Meteorological Society, Journal Year: 2024, Volume and Issue: 150(762), P. 2690 - 2711

Published: June 24, 2024

Abstract With the changing climate, study of fog formation is essential due to impact complexity natural and anthropogenic aerosols. The evolution droplet size distribution in presence different aerosol species remains poorly understood. To make progress towards reducing uncertainty forecasts, Eulerian–Lagrangian particle‐based small‐scale model for diffusional growth droplets used better understand activation growth. simulations are performed using observed data from Winter Fog Experiment over Indira Gandhi International Airport, New Delhi. microphysical properties, such as number concentrations (Nd) liquid water content (LWC), important simulation, evaluated gain more insights. have shown properties at evolutionary stages. Nd effective radius change with variations LWC chemistries (i.e., organics, mix, inorganic). calculated visibility small scale also variation LWC. This compared an existing parametrization parcel–direct numerical simulation calculation. hygroscopicity , which highly related aerosols condensation nuclei, taken into account demonstrate contribution chemistry formation. results highlight that prediction regulated by species.

Language: Английский

---

Chloride (HCl ∕ Cl⁻) dominates inorganic aerosol formation from ammonia in the Indo-Gangetic Plain during winter: modeling and comparison with observations

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(1), P. 41 - 59

Published: Jan. 3, 2023

Abstract. The Winter Fog Experiment (WiFEX) was an intensive field campaign conducted at Indira Gandhi International Airport (IGIA) Delhi, India, in the Indo-Gangetic Plain (IGP) during winter of 2017–2018. Here, we report first comparison South Asia high-temporal-resolution simulation ammonia (NH3) along with ammonium (NH4+) and total NHx (i.e., NH3+ NH4+) using Weather Research Forecasting model coupled chemistry (WRF-Chem) measurements made Monitor for AeRosols Gases Ambient Air (MARGA) WiFEX research site. In present study, incorporated Model Simulating Aerosol Interactions Chemistry (MOSAIC) aerosol scheme into WRF-Chem. Despite simulated values variability often agreeing well observations, frequently higher NH3 lower NH4+ concentrations than observations. Under conditions high relative humidity (RH) hydrogen chloride (HCl) found to promote increase particle fraction (which accounted 49.5 % resolved equivalent units), (Cl−) (29.7 %) as primary anion. By contrast, absence (HCl / Cl−) standard WRF-Chem results prediction sulfate (SO42-) dominant inorganic To understand mismatch associated particulate phase (NH4+ NHx), added HCl Cl− evaluated influence its by conducting three sensitivity experiments model: no HCl, base case (using a published waste burning inventory), 3 × run. We that increased average 13.1 µg m−3 9.8 concentration while reducing 3.2 m−3, which is more accord measurements. Thus increases concentration, further demonstrated emissions factor (−3 NH3_EMI) simulation. Reducing successfully addressed discrepancy between measured modeled NHx. conclude modeling fate Delhi requires correct mechanism accounting dynamics accurate inventories both emissions.

Language: Английский

---