Earth beyond six of nine planetary boundaries

Science Advances, Journal Year: 2023, Volume and Issue: 9(37)

Published: Sept. 13, 2023

This planetary boundaries framework update finds that six of the nine are transgressed, suggesting Earth is now well outside safe operating space for humanity. Ocean acidification close to being breached, while aerosol loading regionally exceeds boundary. Stratospheric ozone levels have slightly recovered. The transgression level has increased all earlier identified as overstepped. As primary production drives system biosphere functions, human appropriation net proposed a control variable functional integrity. boundary also transgressed. modeling different climate and land change illustrates these anthropogenic impacts on must be considered in systemic context.

Language: Английский

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AeroCom phase III multi-model evaluation of the aerosol life cycle and optical properties using ground- and space-based remote sensing as well as surface in situ observations

Atmospheric chemistry and physics, Journal Year: 2021, Volume and Issue: 21(1), P. 87 - 128

Published: Jan. 6, 2021

Abstract. Within the framework of AeroCom (Aerosol Comparisons between Observations and Models) initiative, state-of-the-art modelling aerosol optical properties is assessed from 14 global models participating in phase III control experiment (AP3). The are similar to CMIP6/AerChemMIP Earth System Models (ESMs) provide a robust multi-model ensemble. Inter-model spread species lifetimes emissions appears be that mass extinction coefficients (MECs), suggesting depth (AOD) uncertainties associated with broad spectrum parameterised processes. Total AOD approximately same as I (AP1) simulations. However, we find 50 % decrease (OD) black carbon (BC), attributable combination decreased lifetimes. Relative contributions sea salt (SS) dust (DU) have shifted being equal AP1 SS contributing about 2∕3 natural AP3. This shift linked DU burden, lower MEC, slight lifetime, coarser particle sizes AP3 compared AP1. observations, ensemble median most underestimate all investigated, is, total well fine coarse (AODf, AODc), Ångström exponent (AE), dry surface scattering (SCdry), absorption (ACdry) coefficients. Compared AERONET, by ca. 21 ± 20 (as inferred interquartile range). Against satellite data, biases range −37 (MODIS-Terra) −16 (MERGED-FMI, multi-satellite product), which explain differences individual satellites AERONET measurements themselves. Correlation (R) model observation records generally high (R>0.75), capable capturing spatio-temporal variations AOD. We much larger AODc (∼ −45 25 %) than AODf −15 slightly increased inter-model These results indicate problems SS. bias likely due missing over continental land masses (particularly United States, SE Asia, S. America), while marine sites AATSR SU data suggest more moderate oceanic AODc. Column AEs underestimated 10 16 %. For situations show AE > 2, 35 In contrast, (but one) exhibit large overestimates when dominates (bias +140 if observed < 0.5). Simulated does not span variability. overestimate size (or fine-mode fraction) for fine-dominated coarse-dominated aerosol. must implications water uptake, enhancement, radiative effect, can quantify at this moment. Comparison against Global Atmosphere Watch (GAW) situ mean −35 −20 18 SCdry ACdry, respectively. ACdry suggests will simulate an single albedo too low. ambient air consistent recent findings enhancement hygroscopic growth. broadly negative effects current models. Considerable diversity simulated often found regions are, unfortunately, or only sparsely covered ground-based observations. includes, instance, Sahara, Amazonia, central Australia, South Pacific. highlights need better site coverage would enable us assess models, but also performance products these regions. Using proxy present-day forcing estimates, our %, however, considerably range, +10

Language: Английский

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Validation of GRASP algorithm product from POLDER/PARASOL data and assessment of multi-angular polarimetry potential for aerosol monitoring

Earth system science data, Journal Year: 2020, Volume and Issue: 12(4), P. 3573 - 3620

Published: Dec. 22, 2020

Abstract. Proven by multiple theoretical and practical studies, multi-angular spectral polarimetry is ideal for comprehensive retrieval of properties aerosols. Furthermore, a large number advanced space polarimeters have been launched recently or planned to be deployed in the coming few years (Dubovik et al., 2019). Nevertheless, at present, utilization aerosol products from rather limited, due relatively small polarimetric compared photometric observations, as well challenges making full use extensive information content available these complex observations. Indeed, while recent several new algorithms developed provide enhanced retrievals satellite polarimetry, value yet remains proven. In this regard, paper presents analysis obtained Generalized Retrieval Atmosphere Surface Properties (GRASP) algorithm POLDER/PARASOL After about decade development, GRASP has adapted operational processing observations released. These updated PARASOL/GRASP are publicly (e.g., http://www.icare.univ-lille.fr, last access: 16 October 2018, http://www.grasp-open.com/products/, 28 March 2020); dataset used current study registered under https://doi.org/10.5281/zenodo.3887265 (Chen 2020). The objective comprehensively evaluate First, validation entire 2005–2013 archive was conducted comparing ground-based Aerosol Robotic Network (AERONET) data. subjects optical depth (AOD), absorption (AAOD) single-scattering albedo (SSA) six wavelengths, Ångström exponent (AE), fine-mode AOD (AODF) coarse-mode (AODC) interpolated reference wavelength 550 nm. Second, an inter-comparison with PARASOL/Operational, MODIS Dark Target (DT), Deep Blue (DB) Multi-Angle Implementation Atmospheric Correction (MAIAC) year 2008 performed. Over land both data validations inter-comparisons were separately different surface types, discriminated bins normalized difference vegetation index (NDVI): < 0.2, 0.2 ≤ 0.4, 0.4 0.6, ≥ 0.6. Three analyzed: GRASP/HP (“High Precision”), Optimized Models. consistent but using assumptions modeling accuracies atmospheric radiative transfer (RT) calculations. Specifically, when there direct size distribution refraction. When GRASP/Models, approximated mixture prescribed components, each their own fixed properties, only concentrations those components retrieved. employs most accurate RT calculations, GRASP/Optimized GRASP/Models optimized achieve best trade-off between accuracy speed. all three options, underlying reflectance retrieved simultaneously calculations performed “online” during retrieval. All results show solid quality characteristics. retrievals, however, provided products, e.g., (550 nm) unbiased highest correlation (R ∼ 0.92) fraction (∼ 55.3 %) satisfying requirements Global Climate Observing System (GCOS) AERONET non-negligible positive bias 0.07) low (< 0.2). On other hand, detailed microphysical characteristics (AE, AODF, AODC, SSA, etc.) correlate generally better than do GRASP/Models. Overall, demonstrates high versus AERONET. Evidently, approach more total AOD, limited models used. comparative showed that, based on against AERONET, product similar sometimes higher products. good agreement over ocean. land, especially bright surfaces, degrades differences increase. characteristics, such AE, AODF AODC PARASOL/GRASP, reliable, land. global robust agreement, though some patterns tendencies observed. ocean, PARASOL/Models MODIS/DT agree coefficient 0.92. lower, ranging 0.76 0.85. There no significant offset; surfaces tend values smaller moderate AODs. Seasonal means suggest that biomass burning loading central Africa dust Taklamakan Desert, less northern Sahara. It noticeable also sites somewhat higher, suggesting work rest globe. One potential reasons may general, rely climatology retrievals. shows like POLDER least comparable single-viewing MODIS-like imagers. At same time, AE), additional parameters AAOD SSA.

Language: Английский

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A Comprehensive Description of Multi-Term LSM for Applying Multiple a Priori Constraints in Problems of Atmospheric Remote Sensing: GRASP Algorithm, Concept, and Applications

Frontiers in Remote Sensing, Journal Year: 2021, Volume and Issue: 2

Published: Oct. 19, 2021

Advanced inversion Multi-term approach utilizing multiple a priori constraints is proposed. The used as base for the first unified algorithm GRASP that applicable to diverse remote sensing observations and retrieving variety of atmospheric properties. utilization demonstrated.

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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How well do the CMIP6 models simulate dust aerosols?

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(3), P. 2095 - 2119

Published: Feb. 15, 2022

Abstract. Mineral dust impacts key processes in the Earth system, including radiation budget, clouds, and nutrient cycles. We evaluate aerosols 16 models participating sixth phase of Coupled Model Intercomparison Project (CMIP6) against multiple reanalyses observations. note that both observations used here have their limitations particularly emission deposition are poorly constrained. Most models, multi-model ensemble mean (MEM), capture spatial patterns seasonal cycles global well. However, large uncertainties inter-model diversity found. For example, emissions, primarily driven by model-simulated surface winds, vary a factor 5 across while MEM estimate is double amount reanalyses. The ranges CMIP6 emission, deposition, burden, optical depth (DOD) larger than previous generations models. Models present considerable disagreement over North China America. Here, DOD values overestimated most with 1.2–1.7 times compared to satellite reanalysis datasets. Such overestimates can reach up individual also fail reproduce some features regional distribution, such as accumulation along southern edge Himalayas. Overall, there still models' simulated processes, which feature inconsistent biases throughout life cycle between relationship connecting mass DOD. Our results imply modelled becoming more uncertain become sophisticated. More detailed output size-resolved variables particular, relating future intercomparison projects, needed enable better constraints potential identification observationally constrained links properties.

Language: Английский

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LGHAP: the Long-term Gap-free High-resolution Air Pollutant concentration dataset, derived via tensor-flow-based multimodal data fusion

Earth system science data, Journal Year: 2022, Volume and Issue: 14(2), P. 907 - 927

Published: Feb. 24, 2022

Abstract. Developing a big data analytics framework for generating the Long-term Gap-free High-resolution Air Pollutant concentration dataset (abbreviated as LGHAP) is of great significance environmental management and Earth system science analysis. By synergistically integrating multimodal aerosol acquired from diverse sources via tensor-flow-based fusion method, gap-free optical depth (AOD) with daily 1 km resolution covering period 2000–2020 in China was generated. Specifically, gaps AOD imageries Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra were reconstructed based on set tensors satellites, numerical analysis, situ air quality measurements integrative efforts spatial pattern recognition high-dimensional gridded image analysis knowledge transfer statistical mining. To our knowledge, this first long-term high-resolution China, which spatially contiguous PM2.5 PM10 concentrations then estimated using an ensemble learning approach. Ground validation results indicate that LGHAP are good agreement observations Aerosol Robotic Network (AERONET), R 0.91 RMSE equaling 0.21. Meanwhile, estimations also agreed well ground measurements, values 0.95 0.94 RMSEs 12.03 19.56 µg m−3, respectively. The provides suite maps high to better examine changes over past 2 decades, three major variation periods haze pollution revealed. Additionally, proportion population exposed unhealthy increased 50.60 % 2000 63.81 2014 across reduced drastically 34.03 2020. Overall, generated has potential trigger multidisciplinary applications observations, climate change, public health, ecosystem assessment, management. AOD, PM2.5, datasets publicly available at https://doi.org/10.5281/zenodo.5652257 (Bai et al., 2021a), https://doi.org/10.5281/zenodo.5652265 2021b), https://doi.org/10.5281/zenodo.5652263 2021c), Monthly annual can be https://doi.org/10.5281/zenodo.5655797 2021d) https://doi.org/10.5281/zenodo.5655807 2021e), Python, MATLAB, R, IDL codes provided help users read visualize these data.

Language: Английский

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Global synthesis of two decades of research on improving PM2.5 estimation models from remote sensing and data science perspectives

Earth-Science Reviews, Journal Year: 2023, Volume and Issue: 241, P. 104461 - 104461

Published: May 29, 2023

Language: Английский

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Direct and semi-direct radiative forcing of biomass-burning aerosols over the southeast Atlantic (SEA) and its sensitivity to absorbing properties: a regional climate modeling study

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(21), P. 13191 - 13216

Published: Nov. 10, 2020

Abstract. Simulations are performed for the period 2000–2015 by two different regional climate models, ALADIN and RegCM, to quantify direct semi-direct radiative effects of biomass-burning aerosols (BBAs) in southeast Atlantic (SEA) region. Different simulations have been using strongly absorbing BBAs accordance with recent situ observations over SEA. For July–August–September (JAS) season, single scattering albedo (SSA) total aerosol optical depth (AOD) simulated RegCM models consistent MACv2 climatology MERRA-2 CAMS-RA reanalyses near emission sources. However, above-cloud AOD is slightly underestimated compared satellite (MODIS POLDER) data during transport The effect exerted at continental oceanic surfaces significant both top atmosphere indicate a remarkable contrast SEA (in all-sky conditions), cooling (warming) north (south) 10 ∘S, which agreement climatology. In addition, that responsible an important shortwave heating ∼0.5–1 K per day JAS maxima between 2 4 km a.m.s.l. (above mean sea level). At these altitudes, increase air temperature ∼0.2–0.5 K, highest values being co-located low stratocumulus clouds. Vertical changes limit subsidence mass SEA, creating cyclonic anomaly. opposite continent due lower troposphere stability. BBA on circulation found be models. Changes cloud fraction moderate response presence smoke, differ Gulf Guinea. Finally, results sensitivity properties BBAs. Over (Sc) region, DRE varies from +0.94 W m−2 (scattering BBAs) +3.93 (most BBAs).

Language: Английский

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Multidecadal trend analysis of in situ aerosol radiative properties around the world

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(14), P. 8867 - 8908

Published: July 27, 2020

Abstract. In order to assess the evolution of aerosol parameters affecting climate change, a long-term trend analysis optical properties was performed on time series from 52 stations situated across five continents. The measured scattering, backscattering and absorption coefficients as well derived single scattering albedo, fraction, Ångström exponents covered at least 10 years up 40 for some stations. non-parametric seasonal Mann–Kendall (MK) statistical test associated with several pre-whitening methods Sen's slope used main method. Comparisons general mean square autoregressive bootstrap (GLS/ARB) standard (LMS) enabled confirmation detected MK statistically significant trends assessment advantages limitations each Currently, coefficient are mostly decreasing in Europe North America not Asia, while polar exhibit mix increasing trends. A few also found Australia. Absorption primarily For % sites positive trends, eastern/northern Arctic, 22 negative central America, remaining 26 have which significant. addition evaluating overall series, sequential 10-year segments analyzed. backscattering, earlier periods (10-year ending 2010–2015) Mauna Loa. most stations, present-day albedo were preceded by effect air pollution abatement policies continental is very obvious – there shift 2009–2012 all eastern USA. This radiative broad spatial coverage provides insight into potential effects changes.

Language: Английский

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