Reducing Aerosol Forcing Uncertainty by Combining Models With Satellite and Within‐The‐Atmosphere Observations: A Three‐Way Street

Reviews of Geophysics, Journal Year: 2023, Volume and Issue: 61(2)

Published: May 4, 2023

Abstract Aerosol forcing uncertainty represents the largest climate overall. Its magnitude has remained virtually undiminished over past 20 years despite considerable advances in understanding most of key contributing elements. Recent work produced modest increases only confidence estimate itself. This review summarizes contributions toward reducing aerosol made by satellite observations, measurements taken within atmosphere, as well modeling and data assimilation. We adopt a more measurement‐oriented perspective than reviews subject assessing strengths limitations each; gaps possible ways to fill them are considered. Currently planned programs supporting advanced, global‐scale surface‐based aerosol, cloud, precursor gas modeling, intensive field campaigns aimed at characterizing underlying physical chemical processes involved, all essential. But addition, new efforts needed: (a) obtain systematic aircraft situ capturing multi‐variate probability distribution functions particle optical, microphysical, properties (and associated estimates), co‐variability with meteorology, for major airmass types; (b) conceive, develop, implement suborbital (aircraft plus surface‐based) program systematically quantifying cloud‐scale microphysics, cloud optical properties, cloud‐related vertical velocities aerosol‐cloud interactions; (c) focus much research on integrating unique measurements, reduce persistent forcing.

Language: Английский

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Analysis of MONARC and ACTIVATE Airborne Aerosol Data for Aerosol-Cloud Interaction Investigations: Efficacy of Stairstepping Flight Legs for Airborne In Situ Sampling

Atmosphere, Journal Year: 2022, Volume and Issue: 13(8), P. 1242 - 1242

Published: Aug. 5, 2022

A challenging aspect of conducting airborne in situ observations the atmosphere is how to optimize flight plans for specific objectives and constraints associated with weather restrictions. For aerosol-cloud interaction research, two recent campaigns utilized a “stairstepping” approach whereby an aircraft conducts level legs at various altitudes while moving forward each subsequent leg: 2019 MONterey Aerosol Research Campaign (MONARC) over northeast Pacific 2020–2022 Cloud meTeorology Interactions oVer western ATlantic Experiment (ACTIVATE) northwest Atlantic. We examine homogeneity several atmospheric variables both vertically horizontally marine boundary layer focus on sub-cloud environment. In well-mixed layers, there was generally good horizontal vertical potential temperature, winds, water vapor mixing ratio, trace gases, many aerosol variables. Selected exhibited most variability owing sensitivity humidity near-cloud conditions (supermicrometer concentrations), coastal pollution gradients (e.g., organic mass), small spatial scale phenomena such as new particle formation (aerosol number concentration particles diameter >3 nm). Illustrative cases are described when stairstepping can pose issues requiring extra caution data analysis: (i) poor layers decoupled from those below; (ii) multiple cloud layers; (iii) fluctuating base/top top heights; (iv) across features leading sharp right near coastlines Gulf Stream strong sea surface temperature changes. Results this study provide guide future studies aiming these mission datasets designing campaigns.

Language: Английский

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Spatially coordinated airborne data and complementary products for aerosol, gas, cloud, and meteorological studies: the NASA ACTIVATE dataset

Earth system science data, Journal Year: 2023, Volume and Issue: 15(8), P. 3419 - 3472

Published: Aug. 3, 2023

Abstract. The NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) produced a unique dataset for research into aerosol–cloud–meteorology interactions, with applications extending from process-based studies to multi-scale model intercomparison and improvement as well remote-sensing algorithm assessments advancements. ACTIVATE used two Langley Research Center aircraft, HU-25 Falcon King Air, conduct systematic spatially coordinated flights over northwest Atlantic Ocean, resulting in 162 joint 17 other single-aircraft between 2020 2022 across all seasons. Data cover 574 592 cumulative hours respectively. conducted profiling at different level legs below, in, just above boundary layer clouds (< 3 km) obtained situ measurements of trace gases, aerosol particles, clouds, atmospheric state parameters. Under cloud-free conditions, similarly within immediately layer. Air (the high-flying aircraft) flew approximately ∼ 9 km remote sensing lidar polarimeter while also launching dropsondes (785 total). Collectively, simultaneous data both aircraft help characterize same vertical column atmosphere. In addition individual instrument files, are combined “merge files” on publicly available archive that created time resolutions interest (e.g., 1, 5, 10, 15, 30, 60 s, or matching an product's start stop times). This paper describes flight strategy, complementary products, access usage details, application notes. accessible through https://doi.org/10.5067/SUBORBITAL/ACTIVATE/DATA001 (ACTIVATE Science Team, 2020).

Language: Английский

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Tropospheric aerosols over the western North Atlantic Ocean during the winter and summer deployments of ACTIVATE 2020: life cycle, transport, and distribution

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(4), P. 2087 - 2121

Published: Feb. 19, 2025

Abstract. The Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) is a NASA mission to characterize aerosol–cloud interactions over North Atlantic Ocean (WNAO). Such characterization requires understanding of life cycle, composition, transport pathways, and distribution aerosols WNAO. This study uses GEOS-Chem model simulate aerosol distributions properties that are evaluated against aircraft, ground-based, satellite observations during winter summer field deployments in 2020 ACTIVATE. Transport boundary layer (BL) behind cold fronts was major mechanism for American continental outflow pollution WNAO winter. Turbulent mixing main driver upward sea salt within ventilation out BL composition dominated by salt, which increased summer, followed organics sulfate. Aircraft situ measurements provided useful constraints on wet scavenging GEOS-Chem. generally captured observed features such as outflow, land–ocean gradient, anthropogenic with salt. Model sensitivity experiments elevated smoke injection heights mid-troposphere (versus BL) better reproduced from US wildfires summer. analysis suggests strong hygroscopic growth particles their seeding marine clouds (< 35° N). Future modeling efforts should focus improving parameterizations scavenging, implementing realistic heights, applying high-resolution models resolve vertical transport.

Language: Английский

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Lidar estimates of birch pollen number, mass, and CCN-related concentrations

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(3), P. 1639 - 1657

Published: Feb. 5, 2025

Abstract. The accurate representation of microphysical properties atmospheric aerosol particles – such as the number, mass, and cloud condensation nuclei (CCN) concentration is key to constraining climate forcing estimations improving weather air quality forecasts. Lidars capable vertically resolving optical have been increasingly utilized study aerosol–cloud interactions, allowing for cloud-relevant properties. Recently, lidars employed identify monitor pollen in atmosphere, an understudied particle with health possibly implications. Lidar remote sensing emerging research field, this study, we present first time retrievals CCN, giant CCN (GCCN), ultragiant (UGCCN) birch derived from polarization lidar observations specifically a PollyXT Vaisala CL61 ceilometer at 532 910 nm, respectively. A pivotal role these played by conversion factors necessary convert measurements into This set parameters situ major events Vehmasmäki station eastern Finland. results show that under well-mixed conditions, surface instrumentation can be correlated higher altitudes estimate factors. Better linear agreement was found longer wavelength which attributed combination lower overlap sensitivity bigger compared nm. Then, are applied ground-based against particles. In turn, demonstrates potential network capacity document large-scale outbursts detail thus provide valuable information climate, cloud, modeling efforts, elucidating within system.

Language: Английский

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Sensitivity of aerosol and cloud properties to coupling strength of marine boundary layer clouds over the northwest Atlantic

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(4), P. 2407 - 2422

Published: Feb. 25, 2025

Abstract. Quantifying the degree of coupling between marine boundary layer (MBL) clouds and surface is critical for understanding evolution low explaining vertical distribution aerosols microphysical cloud properties. Previous work has characterized as either coupled or decoupled, but this study rather considers four degrees coupling, ranging from strongly to weakly coupled. We use aircraft data NASA Aerosol Cloud meTeorology Interactions oVer western ATlantic Experiment (ACTIVATE) assess aerosol characteristics following regimes, quantified using differences in liquid water potential temperature (θℓ) total mixing ratio (qt) flight near level (∼150 m) directly below bases: strong (Δθℓ≤1.0 K, Δqt≤0.8 g kg−1), moderate with high Δθℓ (Δθℓ>1.0 Δqt Δqt>0.8 weak kg−1). Results show that (i) turbulence greater regime compared regime, former corresponding more homogeneity 550 nm scattering, integrated volume concentration, giant number concentration (Dp>3 µm) coincident increased MBL mixing; (ii) drop during periods due upward velocity subsequent activation particles; (iii) sea salt tracer species (Na+, Cl−, Mg2+, K+) are present concentrations while tracers continental pollution (Ca2+, non-sea-salt (nss) SO42-, NO3-, oxalate, NH4+) higher mass fraction regime. Additionally, pH Cl-:Na+ (a marker chloride depletion) consistently lower There were also two regimes: had turbulent water, along smaller across levels compared. This shows value defining multiple regimes (rather than traditional versus decoupled) demonstrates behavior various regimes.

Language: Английский

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Spatially-coordinated airborne data and complementary products for aerosol, gas, cloud, and meteorological studies: The NASA ACTIVATE dataset

Published: March 29, 2023

Abstract. The NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) produced a unique dataset for research into aerosol-cloud-meteorology interactions with applications extending from process-based studies to multi-scale model intercomparison and improvement, remote sensing algorithm assessments advancements. ACTIVATE used two Langley Research Center aircraft, HU-25 Falcon King Air, conduct systematic spatially coordinated flights over northwest Atlantic Ocean amounting 162 joint 17 other single-aircraft between 2020 2022 across all seasons. Data cover 574 592 cumulative hours respectively. flew conducted profiling at different level legs below, in, just above boundary layer clouds (< 3 km) obtained in situ measurements of trace gases, aerosol particles, clouds, atmospheric state parameters. In cloud-free conditions, similarly within immediately layer. Air (the high-flyer) approximately ~9 km conducting lidar polarimeter while also launching dropsondes. Collectively, simultaneous data collected both aircraft help characterize same vertical column atmosphere. addition individual instrument files, are combined “merge files” on publicly available archive that created time resolutions interest (e.g., 1, 5, 10, 15, 30, 60 s, or matching an product start stop times). This paper describes flight strategy, complementary products, access usage details, application notes.

Language: Английский

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Differences in aerosol and cloud properties along the central California coast when winds change from northerly to southerly

Published: Feb. 20, 2024

Abstract. Wind reversals resulting in southerly flow along the California coast are not well understood terms of how aerosol and cloud characteristics change. This gap is addressed using airborne field measurements enhanced with data from space-borne remote sensing (Moderate Resolution Imaging Spectroradiometer), surface stations (Interagency Monitoring Protected Visual Environments), models (Navy Aerosol Analysis Prediction System Coupled Ocean/Atmosphere Mesoscale System), a focus on sub- supermicron aerosol, microphysical variables: droplet number concentration (Nd), optical thickness (COT), effective radius (re). Southerly coincided higher values submicron (Na) mass concentrations species representative fine pollution (NO3- nss-SO42-) shipping/continental emissions (V, oxalate, NH4+, Ni, OC, EC). Supermicron Na did change, however, heightened levels acidic reduced Cl-:Na+ suggestive Cl- depletion salt particles. Clouds responded correspondingly flow, more water, similar as phase (e.g., NO3-, nss-SO42-, V), elevated Nd COT re during campaigns liquid water paths. Case study flights help to visualize offshore gradients highlight sensitivity results presence widespread smoke coverage including associated plumes have Na. These implications for aerosol-cloud interactions wind reversals, relevance weather, public welfare, aviation.

Language: Английский

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Representing the effects of giant aerosol in droplet nucleation in E3SMv2

Published: March 4, 2024

Abstract. Giant aerosol, i.e., those with diameters larger than 1 μm, can form large droplets via condensational growth to sizes similar drizzle particles without being activated. In this study, we assess the impacts of giant aerosol on clouds, precipitation, and radiation when activated are directly categorized as raindrops using U.S. Department Energy’s Energy Exascale Earth System Model version 2 (E3SMv2). We find that categorizing reduces cloud liquid water path by 11.38 % globally, most pronounced reduction in mid-latitudes. also approach improves model's ability simulate positive correlation between surface rain rate coarse mode concentration regions low precipitation. The effective radiative forcing associated aerosol-cloud interactions (ERFaci) from -1.37 -0.94 -1.23 W m-2, depending size aerosol. Our results highlight importance a better representation system models provide predictions cloud, climate.

Language: Английский

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Comment on egusphere-2024-392

Published: March 29, 2024

Abstract. Wind reversals resulting in southerly flow along the California coast are not well understood terms of how aerosol and cloud characteristics change. This gap is addressed using airborne field measurements enhanced with data from space-borne remote sensing (Moderate Resolution Imaging Spectroradiometer), surface stations (Interagency Monitoring Protected Visual Environments), models (Navy Aerosol Analysis Prediction System Coupled Ocean/Atmosphere Mesoscale System), a focus on sub- supermicron aerosol, microphysical variables: droplet number concentration (N_d), optical thickness (COT), effective radius (r_e). Southerly coincided higher values submicron (N_a) mass concentrations species representative fine pollution (NO₃^- nss-SO₄^2-) shipping/continental emissions (V, oxalate, NH₄⁺, Ni, OC, EC). Supermicron N_a did change, however, heightened levels acidic reduced Cl^-:Na⁺ suggestive Cl^- depletion salt particles. Clouds responded correspondingly flow, more water, similar as phase (e.g., NO₃^-, nss-SO₄^2-, V), elevated N_d COT r_e during campaigns liquid water paths. Case study flights help to visualize offshore gradients highlight sensitivity results presence widespread smoke coverage including associated plumes have N_a. These implications for aerosol-cloud interactions wind reversals, relevance weather, public welfare, aviation.

Language: Английский

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