Mineral dust aerosol impacts on global climate and climate change

Nature Reviews Earth & Environment, Journal Year: 2023, Volume and Issue: 4(2), P. 71 - 86

Published: Jan. 17, 2023

Language: Английский

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A review of coarse mineral dust in the Earth system

Aeolian Research, Journal Year: 2022, Volume and Issue: 60, P. 100849 - 100849

Published: Dec. 16, 2022

Mineral dust particles suspended in the atmosphere span more than three orders of magnitude diameter, from <0.1 µm to 100 µm. This wide size range makes a unique aerosol species with ability interact many aspects Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. review focuses on coarse super-coarse aerosols, which we respectively define as diameter 2.5–10 10–62.5 We several lines observational evidence indicating that are transported farther previously expected abundance these is substantially underestimated current global models. synthesize previous studies used observations, theories, model simulations highlight impacts aerosols their effects dust-radiation interactions, dust-cloud Specifically, produce net positive direct radiative effect (warming) at top can modify temperature water vapor profiles, influencing distribution clouds precipitation. In addition, contribute substantial fraction ice-nucleating particles, especially temperatures above –23 °C. They also available reactive surfaces for processing deposition flux land ocean biogeochemistry by supplying important nutrients such iron phosphorus. Furthermore, examine limitations representation remote-sensing retrievals. Because uncertainties simulating offer some recommendations facilitate future studies. Overall, conclude an accurate properties critical understanding system.

Language: Английский

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Improved Parameterization for the Size Distribution of Emitted Dust Aerosols Reduces Model Underestimation of Super Coarse Dust

Geophysical Research Letters, Journal Year: 2022, Volume and Issue: 49(8)

Published: April 12, 2022

Aircraft measurement campaigns have revealed that super coarse dust (diameter >10 μm) surprisingly accounts for approximately a quarter of aerosols by mass in the atmosphere. However, most global aerosol models either underestimate or do not include abundance. To address this problem, we use brittle fragmentation theory to develop parameterization emitted size distribution includes emission dust. We implement Community Earth System Model (CESM) and find it brings model good agreement with aircraft measurements close source regions. CESM still underestimates outflow Thus, conclude underestimation atmospheric is part due likely errors deposition processes.

Language: Английский

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A review of coarse mineral dust in the Earth system

EarthArXiv (California Digital Library), Journal Year: 2022, Volume and Issue: unknown

Published: Aug. 31, 2022

Mineral dust particles suspended in the atmosphere span more than three orders of magnitude diameter, from less 0.1 µm to 100 µm. This wide size range makes a unique aerosol species with ability interact many aspects Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. review focuses on coarse super-coarse aerosols, which we respectively define as diameter between 2.5 - 10 62.5 We several lines observational evidence indicating that are transported farther previously expected abundance these is substantially underestimated current global models. synthesize previous studies used observations, theories, model simulations highlight impacts aerosols their effects dust-radiation interactions, dust-cloud In addition, examine limitations representation remote-sensing retrievals. Because contribute uncertainties simulating offer some recommendations facilitate future studies. Overall, conclude an accurate properties critical understanding overall system.

Language: Английский

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Single-scattering properties of ellipsoidal dust aerosols constrained by measured dust shape distributions

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(4), P. 2557 - 2577

Published: Feb. 23, 2023

Abstract. Most global aerosol models approximate dust as spherical particles, whereas most remote sensing retrieval algorithms spheroidal particles with a shape distribution that conflicts measurements. These inconsistent and inaccurate assumptions generate biases in single-scattering properties. Here, we obtain properties by approximating triaxial ellipsoidal observationally constrained distributions. We find that, relative to the optics obtained here, used underestimate albedo, mass extinction efficiency, asymmetry parameter for almost all sizes both shortwave longwave spectra. further are substantially better agreement observations of scattering matrix linear depolarization ratio than algorithms. However, observations, overestimate lidar underestimating backscattering intensity factor ∼2. This occurs largely because computational method simulate (i.e., improved geometric method) underestimates ∼2 other methods (e.g., physical method). conclude distributions can help improve possibly do not use signal.

Language: Английский

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Modeling coarse and giant desert dust particles

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(18), P. 12727 - 12748

Published: Sept. 29, 2022

Abstract. Dust particles larger than 20 µm in diameter have been regularly observed to remain airborne during long-range transport. In this work, we modify the parameterization of mineral dust cycle GOCART-AFWA scheme WRFV4.2.1 also include such coarse and giant particles, further discuss underlying misrepresented physical mechanisms which hamper model reproducing adequately transport particles. The initial particle size distribution is constrained by observations over desert sources. Furthermore, Stokes drag coefficient has updated account for realistic sizes (Re < 105). new code was applied simulate Cabo Verde August 2015 (AER-D campaign). Model results are evaluated against measurements CALIPSO-LIVAS pure product. show that modeled lifetimes coarser shorter those observed. Several sensitivity runs performed reducing artificially particles' settling velocities order compensate underrepresented mechanisms, as non-spherical aerodynamics, relevant schemes. Our simulations reveal with diameters 5.5–17 40–100 better represented under assumption an 80 % reduction velocity (UR80), while ranging between 17 40 a 60 (UR60) scenario. overall statistical analysis indicates best agreement situ downwind (Cabo Verde) achieved (UR40). Moreover, UR80 experiment improves representation vertical structure layers captured vertically resolved observations. current study highlights necessity upgrading existing schemes life-cycle components towards improving assessment dust-related impacts within Earth–atmosphere system.

Language: Английский

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Size-resolved dust direct radiative effect efficiency derived from satellite observations

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(19), P. 13115 - 13135

Published: Oct. 12, 2022

Abstract. The role of mineral dust aerosol in the global radiative energy budget is often quantified by direct effect (DRE). DRE strongly depends on optical depth (DAOD), therefore, efficiency (DREE = / DAOD) widely compared across different studies to eliminate differences due various loads. Nevertheless, DREE still influenced uncertainties associated with particle size distribution (PSD) and properties. In this study, we derive a clear-sky size-resolved dataset both shortwave (SW) longwave (LW) at top atmosphere (TOA) surface based satellite observations (i.e., satellite-retrieved extinction spatial vertical distributions). dataset, geometric diameter from 0.1 100 µm divided into 10 bins corresponding monthly mean (with respect DAOD 532 nm) for each bin derived using Rapid Radiative Transfer Model (RRTM). Three sets state art refractive indices (RI) two shape models (sphere vs. spheroid) are adopted investigate sensitivity absorption shape. As result, contains globally distributed TOA 5∘ (longitude) ×2∘ (latitude) resolution as well RI combination. can be used readily calculate any PSD, including uncertainty induced microphysical properties, (e.g., shape). By calculating climatology retrieved sensors find that pattern induces more than % SW TOA. observation-based PSD around 15–20 atmosphere. assessments further suggest nonsphericity negligible estimations, while turns out most important factor determining DRE, particularly SW.

Language: Английский

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Fine and Coarse Dust Effects on Radiative Forcing, Mass Deposition, and Solar Devices Over the Middle East

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(22)

Published: Nov. 16, 2023

Abstract In desert regions like the Middle East, dust has a profound impact on environment, climate, air quality, and solar devices. The size of particles determines extent these effects. Dust deposition (DD) measurements show that coarse with geometric radius r > 10 μm comprise most deposited mass. Still, are not represented in current models tuned to fit observed aerosol optical depth (AOD). As result, existing reanalysis products underestimate DD emission (DE) almost 3 times. This is first study constrain simulations by both AOD quantify effect fine using WRF‐Chem model. We found that, average, contributes less than 10% shortwave radiative forcing (RF) at surface but comprises more 70% DE. Annual mean net RF over Arabian Peninsula regional seas locally reaches −25 W m −2 . Airborne radii < mainly responsible for significant dimming (5%–10%) radiation, cooling surface, hampering energy production. However, mass primarily linked particles, decreasing efficiency photovoltaic panels 2%–5% per day. Therefore, incorporating model data assimilation would improve overall description balance its environmental systems

Language: Английский

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Particle size distribution and particulate matter concentrations during synoptic and convective dust events in West Texas

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(13), P. 9161 - 9173

Published: July 15, 2022

Abstract. Dust events are an important and complex constituent of the atmospheric system that can impact Earth's climate, environment, human health. The frequency dust in Southern High Plains West Texas has increased over past 2 decades, yet their on air quality this region is still unclear. This due to fact there only one monitoring station measures PM2.5 concentrations (particulate matter with aerodynamic diameter < 2.5 µm), no information other PM sizes or particle size distribution. Aerosol Research Observation Station (AEROS) unit provides insight into local variation concentration during different allows for a better understanding quality. As area prone events, we were wondering if generated by meteorological causes (synoptic vs. convective) would present similar distributions. Thus, project, three measured AEROS compared. Each event originated from direction lasted duration. One was synoptic (10 April 2019) two convective (5 21 June 2019). Measurements mass number concentration, distribution, conditions each (on 10 April) longer (12 h) had stronger wind speed (up 22.1 m s−1), whereas respective 5 20 30 min lower speeds 16.5 13.4 s−1). based daily hourly values showed quality, measurements underestimate events. Observations shorter timescale min) reveal true A comparison distribution all presented increase particles 0.3–10 µm range. Comparisons > show very high Some even ∼ orders magnitude compared time before event. leads us speculate underestimated current (hourly basis) method.

Language: Английский

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Importance of different parameterization changes for the updated dust cycle modeling in the Community Atmosphere Model (version 6.1)

Geoscientific model development, Journal Year: 2022, Volume and Issue: 15(22), P. 8181 - 8219

Published: Nov. 16, 2022

Abstract. The Community Atmosphere Model (CAM6.1), the atmospheric component of Earth System (CESM; version 2.1), simulates life cycle (emission, transport, and deposition) mineral dust its interactions with physio-chemical components to quantify impacts on climate system. accuracy such quantifications relies how well dust-related processes are represented in model. Here we update parameterizations for module, including those emission scheme, aerosol dry deposition size distribution transported dust, treatment particle shape. Multiple simulations were undertaken evaluate model performance against diverse observations, understand each alters modeled simulated direct radiative effect. model–observation comparisons suggest that substantially improved representations achieved primarily through new more physically-based scheme. In comparison, other modifications induced small changes comparisons, except coarse mode, which can be even influential than replacing We highlight introduced here important regions, shedding light further developments required accurately estimating between climate.

Language: Английский

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