Model analysis of biases in satellite diagnosed aerosol effect on cloud liquid water path

Published: July 11, 2024

Abstract. The response in cloud water content to changes condensation nuclei remains one of the major uncertainties determining how aerosols can perturb properties. In this study, we used an ensemble large eddy simulations marine stratocumulus clouds investigate correlation between liquid path and amount nuclei. We compare directly from model derived using equations which are retrieve satellite observations. Our comparison shows that spatial variability properties instrumental noise retrievals optical depth effective radii result bias satellite-derived path. investigation high-resolution data part a cloud, assumption adiabaticity does not hold results similar LWP-CDNC relationship as seen data. addition, our analysis significant positive 18 % 40 droplet number concentration. However, for individual members, mean was very methods. This suggests if cases carefully chosen meteorological conditions it is ensured concentrations well-defined, be confidently determined

Language: Английский

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Model analysis of biases in the satellite-diagnosed aerosol effect on the cloud liquid water path

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(3), P. 1533 - 1543

Published: Feb. 4, 2025

Abstract. The response in cloud water content to changes condensation nuclei remains one of the major uncertainties determining how aerosols can perturb properties. In this study, we used an ensemble large eddy simulations marine stratocumulus clouds investigate correlation between liquid path (LWP) and amount nuclei. We compare directly from model derived using equations which are retrieve satellite observations. Our comparison shows that spatial variability properties instrumental noise retrievals optical depth effective radii results bias satellite-derived path. In-depth investigation high-resolution data part a cloud, assumption adiabaticity does not hold, similar LWP–CDNC (cloud droplet number concentration) relationship as seen data. addition, our analysis significant positive 18 % 40 concentration. However, for individual members, mean was very methods. This suggests if cases carefully chosen meteorological conditions it is ensured concentrations well-defined, be confidently determined

Language: Английский

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Co-variability drives the inverted-V sensitivity between liquid water path and droplet concentrations

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(6), P. 3413 - 3423

Published: March 21, 2025

Abstract. Climatological data of the liquid water path (LWP) and droplet concentration (Nd) often reveal an inverted-V relationship, where LWP increases then decreases as Nd increases. Our findings show that while this response to increase in aligns with proposed causal mechanisms, such entrainment evaporation feedback precipitation suppression, pattern is primarily driven by co-variability between Nd. This arises from (1) large-scale meteorology, which controls both Nd, causing them vary opposite directions simultaneously, (2) microphysical processes, typically accompanied a decrease Consequently, we suggest sensitivity should not be used evidence for positive radiative forcing through adjustments aerosols it largely explained co-variability. We further demonstrate relationship essentially reflects climatological evolution Stratocumulus clouds (Sc). Therefore, background anthropogenic changes should, principle, reflected redistribution occurrences across inverted V maintaining its shape.

Language: Английский

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Marine Stratocumulus Clouds With More Coarse Sea Spray Aerosols Are Brighter

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(7)

Published: April 1, 2025

Abstract The idea of cooling the Earth by marine cloud brightening is well established. All prior studies considered enhancing albedo only with fine aerosols (FA). Adding coarse sea spray (CSA, radius>1 μm) has been thought to have opposite effect. Using nearly a decade satellite observations and global aerosol reanalysis, we found that maximum radiative effect from stratocumulus occurs when FA around 3 μg m −3 CSA 30 . Under low winds high stability conditions, optimal can enhance −95 W −2 , 60% more than adding alone. This CRE response was consistently observed across various cloud‐controlling factors, thus minimizing probability being caused meteorological co‐variability. These findings improve our understanding how different affect Earth's climate, evaluation achieved through brightening, support its feasibility.

Language: Английский

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High sensitivity of cloud formation to aerosol changes

Nature Geoscience, Journal Year: 2025, Volume and Issue: unknown

Published: April 3, 2025

Language: Английский

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Biomass burning in critical fire region over the Maritime Continent from 2012 to 2021: A review of the meteorological influence and cloud-aerosol-radiation interactions

Atmospheric Environment, Journal Year: 2024, Volume and Issue: 320, P. 120324 - 120324

Published: Jan. 2, 2024

Language: Английский

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Opposite effects of aerosols and meteorological parameters on warm clouds in two contrasting regions over eastern China

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(8), P. 4651 - 4673

Published: April 18, 2024

Abstract. The sensitivity (S) of cloud parameters to the influence different aerosol and meteorological has in most previous aerosol–cloud interaction (aci) studies been addressed using traditional statistical methods. In current study, relationships between droplet effective radius (CER) optical depth (AOD, used as a proxy for condensation nuclei, CCN), i.e., CER AOD, are investigated with constraints AOD liquid water path (LWP). addition methods, geographical detector method (GDM) is applied this study quantify relative importance effects parameters, well their interaction, on S. Moderate Resolution Imaging Spectroradiometer (MODIS) C6 L3 data European Centre Medium-Range Weather Forecasts (ECMWF) ERA-5 reanalysis data, period from 2008 2022, were investigate aci over eastern China. Two contrasting areas selected: heavily polluted Yangtze River Delta (YRD) relatively clean area East China Sea (ECS). Linear regression analysis shows that decreases increase (negative S) moderately atmosphere (0.1<AOD<0.3) ECS, whereas, contrast, increases increasing (positive (AOD>0.3) YRD. Evaluation S function LWP negative interval [40 g m−2, 200 m−2], substantially stronger larger. YRD, positive [0 120 m−2] does not change notably interval. further larger higher low tropospheric stability (LTS) humidity (RH) but lower pressure vertical velocity (PVV). Over there no significant LTS relationship AOD. GDM an independent analyze (RH, PVV). also interactions two thus obtain information confounding aci. sensitive almost all considered except top (CTP), than any factors. Among factors, PVV least RH. explanatory power much smaller RH, which statistically CTP can explain 74 % variation CTP. results show more combination parameter each alone, due co-variation both cannot be excluded.

Language: Английский

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2D signal estimation for sparse distributed target photon counting data

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: May 6, 2024

Abstract In this study, we explore the utilization of penalized likelihood estimation for analysis sparse photon counting data obtained from distributed target lidar systems. Specifically, adapt Poisson Total Variation processing technique to cater application. By assuming a noise model count observations, our approach yields denoised estimates backscatter flux and related parameters. This facilitates raw signals with exceptionally high temporal range resolutions (demonstrated here 50 Hz 75 cm resolutions), including acquired through time-correlated single counting, without significant sacrifice resolution. Through examination involving both simulated real-world 2D atmospheric data, method consistently demonstrates superior accuracy in signal recovery compared conventional histogram-based commonly employed applications.

Language: Английский

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Exploring aerosol–cloud interactions in liquid-phase clouds over eastern China and its adjacent ocean using the WRF-Chem–SBM model

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(16), P. 9101 - 9118

Published: Aug. 22, 2024

Abstract. In this study we explore aerosol–cloud interactions in liquid-phase clouds over eastern China (EC) and its adjacent ocean (ECO) using the WRF-Chem–SBM model with four-dimensional assimilation. The results show that our simulations analyses based on each vertical layer provide a more detailed representation of relationship compared to column-based which have been widely conducted previously. For aerosol activation, cloud droplet number concentration (Nd) generally increases (Naero) at low Naero decreases high Naero. main difference between EC ECO is Nd faster than due abundant water vapor, whereas Naero, when activation suppressed, shows significant fluctuation strong surface effects (longwave radiation cooling terrain uplift) intense updrafts. Cloud liquid content (CLWC) Nd, but increase rate gradually slows down for precipitating clouds, while CLWC then non-precipitating clouds. Higher can be found ECO, transition-point value changes from increasing decreasing also higher EC. Aerosol strongest moderate relatively fast processes are limited by humidification, diverse atmospheric allow occur under warming or drying conditions.

Language: Английский

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Analysis of the cloud fraction adjustment to aerosols and its dependence on meteorological controls using explainable machine learning

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(22), P. 13025 - 13045

Published: Nov. 26, 2024

Abstract. Aerosol–cloud interactions (ACI) have a pronounced influence on the Earth's radiation budget but continue to pose one of most substantial uncertainties in climate system. Marine boundary-layer clouds (MBLCs) are particularly important since they cover large portion surface. One biggest challenges quantifying ACI from observations lies isolating adjustments cloud fraction (CLF) aerosol perturbations covariability and local meteorological conditions. In this study, isolation is attempted using 9 years (2011–2019) near-global daily satellite products combination with reanalysis data parameters. With cloud-droplet number concentration (Nd) as proxy for aerosol, MBLC CLF predicted by region-specific gradient boosting machine learning (ML) models. By means SHapley Additive exPlanation (SHAP) regression values, sensitivity Nd factors well influences Nd–CLF quantified. The regional ML models able capture, average, 45 % variability. Based our statistical approach, global patterns suggest that positively associated Nd, stratocumulus-to-cumulus transition regions Southern Hemispheric midlatitudes. However, retrieval bias may contribute non-causality these positive sensitivities, hence should be considered upper-bound estimates. estimated inversion strength (EIS) ubiquitously strongest tropical subtropical topped stratocumulus within Globally, increased sea-surface temperature (SST) reduces CLF, regions. spatial horizontal wind components free troposphere point impact synoptic-scale weather systems vertical shear MBLCs. relationship found depend more selected thermodynamical variables than dynamical particular EIS SST. midlatitudes, stronger amplify relationship, while not observed regions, amplified higher SSTs, potentially pointing frequently delaying expected climatic changes SST thus future forcings adjustment. novel data-driven framework, whose limitations also discussed, produces quantification response aerosols, taking into account covariations meteorology.

Language: Английский

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