Rate of atmospheric brown carbon whitening governed by environmental conditions

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(38)

Published: Sept. 12, 2022

Biomass burning organic aerosol (BBOA) in the atmosphere contains many compounds that absorb solar radiation, called brown carbon (BrC). While BBOA is atmosphere, BrC can undergo reactions with oxidants such as ozone which decrease absorbance, or whiten. The effect of temperature and relative humidity (RH) on whitening has not been well constrained, leading to uncertainties when predicting direct radiative climate. Using an flow-tube reactor, we show by oxidation strongly dependent RH temperature. a poke-flow technique, viscosity also depends these conditions. measured rate described data, assuming due occurring bulk BBOA, within thin shell beneath surface. our combined datasets, developed kinetic model this process, lifetime 1 d less below ∼1 km altitude but often much longer than above altitude. Including dependence chemical transport causes large change predicted warming Overall, results illustrate need be considered understand role atmosphere.

Language: Английский

---

Using the Black Carbon Particle Mixing State to Characterize the Lifecycle of Biomass Burning Aerosols

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(20), P. 14315 - 14325

Published: Oct. 6, 2022

The lifecycle of black carbon (BC)-containing particles from biomass burns is examined using aircraft and surface observations the BC mixing state for plume ages ∼15 min to 10 days. Because nonvolatile chemically inert, changes in BC-containing are driven solely by particle coating, which mainly secondary organic aerosol (SOA). coating mass initially increases rapidly (kgrowth = 0.84 h–1), then remains relatively constant 1–2 days as dilution no longer supports further growth, decreases slowly until only ∼30% maximum after (kloss 0.011 h–1). ratio coating-to-core a with 100 nm mass-equivalent diameter core reaches ∼20 few hours drops ∼5 aging. initial increase can be used determine SOA formation rates. slow loss material, not captured global models, comprises dominant fraction these particles. Coating-to-core ratios stratosphere much greater than those free troposphere indicating different lifecycle.

Language: Английский

---

The characterization of long-range transported North American biomass burning plumes: what can a multi-wavelength Mie–Raman-polarization-fluorescence lidar provide?

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(8), P. 5399 - 5414

Published: April 25, 2022

Abstract. This article presents a study of long-range transported biomass burning aerosols (BBA) originated from the North American wildfires in September 2020. The BBA plumes presented this were troposphere and underwent 1–2 weeks aging before arriving at lidar station ATOLL (ATmospheric Observatory LiLle) northern France. A novel lidar-derived dataset, 2α+3β+3δ+ϕ (α: extinction coefficient; β: backscatter δ: particle linear depolarization ratio, i.e., PLDR; ϕ: fluorescence capacity), is provided for characterization BBA. capacity an intensive aerosol parameter describing ability producing when exposed to UV excitation. In our observations, obvious variations parameters, reflecting variability properties, detected. PLDRs varied less than 0.03 all wavelengths 0.15–0.22 0.12–0.16, respectively, 355 532 nm. related Angström exponent was within range −0.3 1.0 × 10−4–4.0 10−4. Lidar ratio as low 24 ± 4 sr (50 8 sr) observed (532) nm on 17–18 September, which lower most previously aged BBAs. These are likely correlated with combustion process, lifting conditions (temperature, humidities, etc.) process. addition, results indicate could act ice nucleating particles tropospheric conditions. channel proves be important added value aerosol–cloud interactions studies, due its high sensitivity. With increase wildfire occurrence intensity, BBAs become more atmospheric component. context, we show potential dataset particles' understanding their role cloud processes.

Language: Английский

---

Air Pollution Interactions with Weather and Climate Extremes: Current Knowledge, Gaps, and Future Directions

Current Pollution Reports, Journal Year: 2024, Volume and Issue: 10(3), P. 430 - 442

Published: Feb. 22, 2024

Language: Английский

---

Hourly biomass burning emissions product from blended geostationary and polar-orbiting satellites for air quality forecasting applications

Remote Sensing of Environment, Journal Year: 2022, Volume and Issue: 281, P. 113237 - 113237

Published: Sept. 6, 2022

Language: Английский

---

Important role of stratospheric injection height for the distribution and radiative forcing of smoke aerosol from the 2019–2020 Australian wildfires

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(15), P. 9969 - 9985

Published: Aug. 4, 2022

Abstract. More than 1 Tg smoke aerosol was emitted into the atmosphere by exceptional 2019–2020 southeastern Australian wildfires. Triggered extreme fire heat, several deep pyroconvective events carried directly stratosphere. Once there, remained airborne considerably longer in lower atmospheric layers. The thick plumes traveled eastward, thereby being distributed across high and mid-latitudes Southern Hemisphere, enhancing opacity. Due to increased lifetime of plume, its radiative effect compared that remains altitudes. Global models describing aerosol-climate impacts lack adequate descriptions emission height aerosols from intense Here, we demonstrate, a combination modeling lidar observations, importance representation those high-altitude layers for estimating energy budget. Through observation-based input simulations, wildfire emissions pyroconvection are explicitly prescribed stratosphere different scenarios. Based on our fires caused significant top-of-atmosphere (TOA) hemispheric instantaneous direct forcing signal reached magnitude comparable induced anthropogenic absorbing aerosol. Up +0.50 W m−2 modeled at TOA, averaged Hemisphere (+0.25 globally) January March 2020 under all-sky conditions. At surface, other hand, an solar up −0.81 found clear-sky conditions, with respective estimates depending model configuration subject uncertainties optical properties. Since wildfires expected occur more frequently rapidly changing climate, findings suggest must be adequately considered climate projections order obtain reasonable budget changes.

Language: Английский

---

Wildfire particulate matter as a source of environmentally persistent free radicals and reactive oxygen species

Environmental Science Atmospheres, Journal Year: 2023, Volume and Issue: 3(3), P. 581 - 594

Published: Jan. 1, 2023

Wildfire particulate matter contains high amounts of environmentally persistent free radicals and generates reactive oxygen species with implications for air quality public health.

Language: Английский

---

Mass spectrometric analysis of unprecedented high levels of carbonaceous aerosol particles long-range transported from wildfires in the Siberian Arctic

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(1), P. 553 - 576

Published: Jan. 15, 2024

Abstract. Wildfires in Siberia generate large amounts of aerosols, which may be transported over long distances and pose a threat to the sensitive ecosystem Arctic. Particulate matter (PM) aged wildfire plumes originating from Yakutia August 2021 was collected Nadym on Bely Island (both northwestern Siberia). An advanced analysis chemical composition aerosol particles conducted through multi-wavelength thermal–optical carbon analyzer (TOCA) coupled resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS) as well ultra-high-resolution Fourier-transform ion cyclotron resonance (FT-ICR MS). In Nadym, concentrations organic (OC) elemental (EC) peaked at 100 40 µg m−3, respectively, associated with Angström absorption exponents for 405 808 nm (AAE405/808) between 1.5 3.3. The weekly average 8.9 m−3 OC 0.3 EC AAE405/808 close unity. particular, ambient had distinct biomass burning profile pyrolysis products carbohydrates, such cellulose hemicellulose, lignin resinoic acids. However, temporarily higher five- six-ring polycyclic aromatic hydrocarbons (PAHs), different PAH signature burning, suggest contribution regional gas flaring. FT-ICR MS electrospray (ESI) revealed complex mixture highly functionalized compounds, containing up 20 oxygen atoms, nitrogen- sulfur-containing moieties. Concentrations markers were substantially lower than flanked by appearance unique compounds content, molecular weight, aromaticity. Back-trajectory satellite-derived optical depth suggested long-range transport center Yakutian plume periphery Island. Owing its center, it is demonstrated how dilution affects during atmospheric aging.

Language: Английский

---

New particle formation in the tropical free troposphere during CAMP²Ex: statistics and impact of emission sources, convective activity, and synoptic conditions

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(17), P. 9853 - 9871

Published: Sept. 6, 2023

Abstract. Nucleation in the free troposphere (FT) and subsequent growth of new particles represent a globally important source cloud condensation nuclei (CCN). Whereas particle formation (NPF) has been shown to occur frequently upper over tropical oceans, there have few studies NPF at lower altitudes. In addition, impact urban emissions biomass burning on marine FT remains poorly understood. this study, we examine mid-troposphere (3–8.5 km) ocean coastal region using airborne measurements during recent Cloud, Aerosol Monsoon Processes Philippines Experiment (CAMP2Ex). was mostly observed above 5.5 km coincided with elevated relative humidity (RH) reduced sink (CS), suggesting that occurs convective outflow. The frequency increases altitude, reaching ∼ 50 % 8 km. An abrupt decrease coincides early monsoon transition is attributed increased CS resulting from activity more frequent transport aged plumes. Surprisingly, large fraction events background air were morning, likely made possible by very low despite actinic flux. Convectively detrained biomass-burning plumes fresh enhance as result precursor concentrations scavenging pre-existing particles. contrast, suppressed where reactive precursors are consumed, while relatively high. This study shows strong FT. results also illustrate competing influences different variables interactions among anthropogenic emissions, clouds, meteorology, which lead under variety conditions environments.

Language: Английский

---

Intense formation of secondary ultrafine particles from Amazonian vegetation fires and their invigoration of deep clouds and precipitation

One Earth, Journal Year: 2024, Volume and Issue: 7(6), P. 1029 - 1043

Published: June 1, 2024

New particle formation (NPF) in fire smoke is thought to be unlikely due large condensation and coagulation sinks that scavenge molecular clusters. We analyze aircraft measurements over the Amazon find fires significantly enhance NPF ultrafine (UFP < 50 nm diameter) numbers compared background conditions, contrary previous understanding. identify nucleation of dimethylamine with sulfuric acid, which aided by extremely low volatility organics biomass-burning smoke, can overcome explain observations. show freshly formed clusters rapidly grow UFP sizes through secondary organic aerosol formation, leading a 10-fold increase number concentrations. contrasting effect UFPs on deep convective clouds larger particles from primary emissions for case investigated here. intensify precipitation increased condensational heating, while delay reduce precipitation.

Language: Английский

---