Influence Of Aerosols Research Articles

Dust Aerosol Impacts on the Time of Cloud Formation in the Badain Jaran Desert Area

AbstractDust, as absorbing aerosols, can change the stability of the atmosphere through radiative effects, thereby affecting the formation and characteristics of clouds. In order to explore the influence of dust aerosols on cloud formation, this study takes the Badain Jaran Desert area as the research area where cloud formation is less disturbed by human activities compared to other densely populated areas such as the North China Plain, and uses the high temporal resolution Himawari‐8 satellite data to identify 469 cases with cloud formation after 03:00 UTC (11:00 Beijing time). Through the analysis of individual cases, we find that the cloud formation time is dominated by the low tropospheric stability (LTS) when the total precipitable water (TPW) is less than about 18.5 kg/m2, and greatly affected by the TPW when it is larger than 18.5 kg/m2. Dust aerosols near the ground absorb shortwave solar radiation, making the atmospheric structure unstable (decreased LTS) and conducive to cloud formation. Statistically, for every 0.1 increase in aerosol optical depth, the cloud formation time is advanced about 138 min compared to low aerosol cases. Further analysis shows that dust aerosols actually inhibit the formation of convective clouds through microphysical processes when the TPW is small, while promote the formation of convective clouds through radiative processes when the TPW is large. This study reveals the effects of dust aerosols on the time of cloud formation along with the underlying mechanisms, which provides observational support for improving cloud parameterization in numerical models.

Satellite-Observed Four-Dimensional Spatiotemporal Characteristics of Maritime Aerosol Types over the Coastal Waters of the Guangdong–Hong Kong–Macao Greater Bay Area and the Northern South China Sea

Aerosol is important to climate and air pollution, and different aerosol types have a non-negligible impact on the environment and climate system. Based on long-term satellite lidar profiles from 2006 to 2020, the four-dimensional (x-y-z-t) spatiotemporal characteristics of different aerosol types, including clean marine (CM), dust (DU), polluted continental/smoke (PC), clean continental (CC), polluted dust (PD), elevated smoke (ES), and dusty marine (DM), over the coastal waters of the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) were revealed for the first time and compared to the surrounding northern South China Sea (NSCS). (1) The dominant aerosol types in both study areas were found to be CM, ES, and DM, whose proportions summed up to more than 85%. In spring, ES was the dominant aerosol type (>40%); in other seasons, CM dominated (>34%). The proportions of anthropogenic aerosols (PC, PD, and ES) and dust-related aerosols (DU, PD, and DM) were higher in spring and winter than in summer and autumn. (2) Vertically, the number of all aerosol types declined with increasing altitude, with the exception of abnormal increase at the heights of approximately 1.5–2.8 km in spring, which was probably attributed to the effect of local and regional anthropogenic pollutants. Below the height of 2 km, the main aerosol types were CM and DM, whereas ES, PD, and DU aerosols were dominant above 2 km. (3) Horizontally, the dominant aerosol types were spatially uniform in the lower atmosphere (<2 km), while higher altitudes (especially > 4 km) showed significant horizontal heterogeneity in space. The proportion of anthropogenic aerosols over the coastal waters of the GBA was higher than that over the NSCS, due to terrestrial pollution transportation. (4) In terms of the long-term trend, the proportion of CM aerosols was found to be steadily increasing, with the anthropogenic aerosols and dust-related aerosols showing a fluctuating and decreasing trend, which resulted from the enforcement of effective air pollution control policies. Overall, the terrestrial aerosol influence tended to decrease in the study areas. The insight into aerosol types and its variation will facilitate the understanding of the aerosol climate effects and pollutant control in the coastal waters of the GBA and the NSCS.

Characterization of columnar aerosol over a background site in Central Asia

Ground-based observational characterization of atmosphere aerosols over Central Asia is very limited. This study investigated the columnar aerosol characteristics over Issyk-Kul, Kyrgyzstan, a background site in Central Asia using the long-term (∼14 years: August 2007–November 2021) data acquired with the Cimel sunphotometer. The mean aerosol optical depth (AOD) and Ångström exponent (AE) during the observation period were 0.14 ± 0.10 and 1.19 ± 0.41, respectively. Both AOD and AE varied across seasons, with highest AOD in spring (0.17 ± 0.17). Regarding the aerosol types, clean continental aerosols were dominant type (65%), followed by mixed aerosols (∼19%), clean marine aerosols (∼14%), dust (0.8%), and urban/industrial and biomass burning aerosol (0.7%). The aerosol volume size distribution was bimodal indicating the influence of both anthropogenic and natural aerosols with clear dominance of coarse mode during the spring season. Mainly dust and mixed aerosols were present during high aerosol episodes while the coarse mode aerosol volume concentration was 7.5 (strong episodes) and ∼19 (extreme episodes) times higher than the whole period average. Aerosol over this background sites were from local and regional sources with some contribution of long-range transport.

Contributions of primary sources to submicron organic aerosols in Delhi, India

Abstract. Delhi, India, experiences extremely high concentrations of primary organic aerosol (POA). Few prior source apportionment studies on Delhi have captured the influence of biomass burning organic aerosol (BBOA) and cooking organic aerosol (COA) on POA. In a companion paper, we develop a new method to conduct source apportionment resolved by time of day using the underlying approach of positive matrix factorization (PMF). We call this approach “time-of-day PMF” and statistically demonstrate the improvements of this approach over traditional PMF. Here, we quantify the contributions of BBOA, COA, and hydrocarbon-like organic aerosol (HOA) by applying positive matrix factorization (PMF) resolved by time of day on two seasons (winter and monsoon seasons of 2017) using organic aerosol measurements from an aerosol chemical speciation monitor (ACSM). We deploy the EPA PMF tool with the underlying Multilinear Engine (ME-2) as the PMF solver. We also conduct detailed uncertainty analysis for statistical validation of our results. HOA is a major constituent of POA in both winter and the monsoon. In addition to HOA, COA is found to be a major constituent of POA in the monsoon, and BBOA is found to be a major constituent of POA in the winter. Neither COA nor the different types of BBOA were resolved in the seasonal (not time-resolved) analysis. The COA mass spectra (MS) profiles are consistent with mass spectral profiles from Delhi and around the world, particularly resembling MS of heated cooking oils with a high m/z 41. The BBOA MS have a very prominent m/z 29 in addition to the characteristic peak at m/z 60, consistent with previous MS observed in Delhi and from wood burning sources. In addition to separating the POA, our technique also captures changes in MS profiles with the time of day, a unique feature among source apportionment approaches available. In addition to the primary factors, we separate two to three oxygenated organic aerosol (OOA) components. When all factors are recombined to total POA and OOA, our results are consistent with seasonal PMF analysis conducted using EPA PMF. Results from this work can be used to better design policies that target relevant primary sources of organic aerosols in Delhi.

Seasonal cycles and long-term trends of arctic tropospheric aerosols based on CALIPSO lidar observations

Notable warming trends have been observed in the Arctic, with tropospheric aerosols being one of the key drivers. Here the seasonal cycles of three-dimensional (3D) distributions of aerosol extinction coefficients (AECs) and frequency of occurrences (FoOs) for different aerosol subtypes in the troposphere over the Arctic from 2007 to 2019 are characterized capitalizing on Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) Level-3 gridded aerosol profile product. Seasonal contributions of total and type-dependent aerosols through their partitioning within the planetary boundary layer (PBL) and free troposphere (FT) are also quantified utilizing the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) PBL height data. The results show substantial seasonal and geographical dependence in the distribution of aerosols over the Arctic. Sulfate, black carbon (BC), and organic carbon (OC) contribute most of the total AEC, with Eurasia being the largest contributor. The vertical structure of AECs and FoOs over the Arctic demonstrates that the vertical influence of aerosols is higher in eastern Siberia and North America than in northern Eurasia and its coasts. When the total aerosol optical depth (TAOD) is partitioned into the PBL and FT, results indicate that the contributions of TAOD within the FT tend to be more significant, especially in summer, with the FT contributes 64.2% and 69.2% of TAOD over the lower (i.e., 60° N–70° N) and high (i.e., north of 70° N) Arctic, respectively. Additionally, seasonal trend analyses suggest Arctic TAOD exhibits a multi-year negative trend in winter, spring, and autumn and a positive trend in summer during 2007–2019, due to an overall decrease in sulfate from weakened anthropogenic emissions and a significant increase in BC and OC from enhanced biomass burning activities. Overall, this study has potential implications for understanding the seasonal cycles and trends in Arctic aerosols.

Launch of a sounding balloon for horizontal and vertical modelling of ALAN propagation in the atmosphere

ABSTRACT The propagation of light radiation in the atmosphere is a topic that needs to be properly analysed to mitigate its negative influence on astronomical observations. This work describes a novel approach for evaluating atmospheric propagation of artificial light at night (ALAN), emphasizing the dependence on altitude and aerosols. It is based on an innovative experiment using a sounding balloon equipped with two sky-quality meters (SQM): one vertically pointed at 30° (SQM-V) and the other horizontally at 90° (SQM-H) from the zenith. The system was launched during astronomical night conditions from an area of the Italian Apennines with low ground light emission and crossed the Tuscan sky, observing the vertical and horizontal ALAN propagation. The data analysis of the two SQMs and their georeferentiation through altitude and trajectory reconstruction allows us to model the propagation of light in the experimental field of view from a few hundred metres up to an altitude of about 30 km. In this work, the main focus is given to the tropospheric part of the atmosphere up to 12 500 m: the processed data are used to validate a theoretical model taking into account the altitude, course of the balloon, atmospheric composition, and population of the cities overflown by the balloon, obtaining a correlation of 0.85 with SQM-H and 0.91 with SQM-V. The magnitude values of close to 21.5 $\mathrm{mag\, arcsec}^{-2}$ measured by SQM-V at 2000 m are an important experimental result for evaluating the influence of aerosols and altitude on ALAN propagation.

Potential Relationship Between Aerosols and Positive Cloud-to-Ground Lightning During the Warm Season in Sichuan, Southwest China

This study discussed the influence of aerosols on the relative frequency of positive cloud-to-ground (CG) lightning and its dependence on thermodynamic and cloud-related factors in Sichuan during the warm season from 2005 to 2017. The relative frequency of positive CG lightning is defined as the proportion of positive CG lightning flashes to total CG lightning flashes. Although the total CG lightning density in the Western Sichuan Plateau is significantly lower than that in the Sichuan Basin, the relative frequency of positive CG lightning is higher than that in the basin. Convective available potential energy (CAPE) and vertical wind shear in the low-to-mid level of the troposphere (SHEAR-5 km) are the controlling factors of positive CG lightning frequency. A small CAPE and a large SHEAR-5 km represent weak convection, which is more conducive to the generation of positive CG lightning. The upper main positive charge region in a thriving thunderstorm is higher from the ground, which is not conducive to the transport of positive charge to the ground, so it is not conducive to the generation of positive CG lightning. In the basin, the relationship between aerosols and positive lightning is not significant, which may be due to the strong total CG lightning and the low proportion of positive CG lightning. In the plateau, both sulfate aerosol and black carbon (BC) aerosol have a significant inhibition effect on the positive CG lightning relative frequency. Sulfate aerosol stimulates the ice-phase process through a microphysical effect and promotes the development of convection. The distribution of the main positive charge center is higher, which is not conducive to the transport of positive charge to the ground and the generation of positive CG lightning. The significant heating effect of BC aerosol on the lower troposphere makes the convective development more vigorous and is not conducive to the occurrence of positive CG lightning.

Influence of smoke aerosols on low-level clouds over the Indian region during winter

The effect of smoke aerosols on the low-level clouds over the Indian landmass during the winter season is examined using 15 years (2005–2019) of long-term multi-satellite observations and reanalyses (MERRA-2 and ERA-5) datasets. Climatologically higher values of aerosol optical depth (AOD) (> 0.6), Angstrom exponent (> 1.5), UV-aerosol index (> 0.7), and black carbon and organic carbon (BC + OC) extinction aerosol optical thickness (EXTAOT) (> 0.18) are found over the Indo-Gangetic Plain (IGP) compared to the rest of India indicating the dominance of smoke aerosols over the region. However, considerable enhancements in AOD (~ 60%) and (BC + OC) EXTAOT (20–40%) are observed over some parts of eastern India (particularly Odisha and Chhattisgarh) and central-south India compared to IGP (< 10% and < 5% respectively) in the recent years. Also, fire activities are increasing over almost the same region where smoke aerosols increased considerably, suggesting a significant role of local biomass burning (BB) in the observed rise of smoke aerosols. However, prevailing wind patterns and HYSPLIT backward air mass trajectories indicate that long-range transport from the upper IGP regions and northwestern sides of India and beyond could also increase smoke loading over this region. Climatologically, distinct spatial patterns with moderate cloud fraction (CF) (0.5–0.6) and comparatively larger liquid cloud effective radius (CER) (16–17 μm) are found over the IGP region. This study suggests that mainly low-level clouds contribute to this distinct signature of cloud distributions. However, a significant increase in CF (50–60%) is observed over almost the same region where smoke aerosols showed a considerable rise, implying the possible influence of smoke aerosols on the low-level clouds. While CF and CER showed a noticeable increase in the polluted condition, cloud optical thickness and liquid cloud water path showed a consequent decrease with increased aerosol loading. CALIPSO images suggest that mostly a mixture of dust, polluted dust, and polluted continental/smoke aerosols showed clear dominance over the inland areas, mostly confined within 2 km altitude over almost the entire study domain. However, an elevated layer of absorbing aerosols (smoke and polluted dust) over the low-level cloud increased the cloud fraction through the ‘aerosol-cloud-boundary layer’ feedback mechanism.

Simulation of the effects of biomass burning in a mesoscale convective system in the central amazon

During the dry season of 2014, the formation of a mesoscale convective system (MCS) caused intense precipitation and strong winds in the central Amazon region. In this period, cases of MCS that occurred during the days when there were higher concentrations of CO were analyzed. Through this criterion, a case of MCS occurred on August 16th, 2014 was selected. We used the chemical-atmospheric model WRF-Chem to assess the influence of biomass burning aerosol on the intensity of precipitation, winds, vertical and horizontal transport associated with this convective system. We show that biomass burning aerosol reduces the strength of the mesoscale convective system, with less vertical and horizontal transport of carbon monoxide and ozone. In the absence of biomass burning aerosol downdrafts and precipitation rate are more intense, and cloud development up to 5 km is more developed, making the horizontal flow and vertical transport of ozone more intense, however, much more efficient in reducing the concentrations of other gases.

Unified Topographic and Atmospheric Correction for Remote Imaging Spectroscopy

Models linking surface characteristics within incident solar radiation are inexorably dependent on the topography of the given region. To date, however, most operational surface reflectance retrievals treat this dependence by assuming a flat terrain, leading to significant deviations in the estimated reflectance. Here, we demonstrate that incorporating dynamic topography directly into the joint surface and atmospheric model during retrievals has several advantages. First, it allows for a more complete physical accounting of downwelling illumination, providing more accurate estimates of the absolute magnitude of reflectance. Second, it facilitates a superior resolution of the atmospheric state, most notably due to the confounding influence of atmospheric aerosols and unresolved topographic effects. Our methodology utilizes a practical, high-fidelity, model-driven approach to separate out diffuse and direct irradiation and account for topographic effects during the joint inversion of atmosphere and surface properties. We achieve this by enhancing the atmosphere/surface inversion to account for the radiative transfer effects of surface slope. We further demonstrate how uncertainties in topographic features can be quantified and leveraged within our formulation for a more realistic posterior uncertainty estimates. Our results demonstrate that the inclusion of topographic effects into the retrieval model reduces errors in the reflectance of an only moderately rugged terrain by more than 15%, and that a post hoc accounting of topography cannot achieve these same results.

Significant influence of aerosol on cloud-to-ground lightning in the Sichuan Basin

The effects of aerosols under special terrain on lightning activities in the Sichuan Basin (SB) are studied using the cloud-to-ground (CG) lightning data and aerosol optical depth (AOD) data from 2010 to 2018. Interesting results show that the topographic drop plays an important role in the process of aerosol affecting lightning. The great topographic drop in the western SB is conducive to the production of CG lightning. Both the CG lightning production and AOD in the northwest and southwest of the basin decrease in fluctuation during the study period. It can be inferred that the reduction of aerosol results in the decrease of lightning activity. Due to the topographic drop in the northwest of the basin being greater than that in the southwest, the correlation of 0.64 between AOD and CG lightning in the northwest of the basin is larger than that of 0.31 in the southwest. Since the lightning activity in SB generally occurs at night, the aerosol-radiation interaction (ARI) has an insignificant influence on the occurrence of convection. Under this condition, it can be inferred that the aerosol-cloud interactions (ACI) are dominant over SB region. These could better support the reduction of lightning generation.

Surface PM2.5 mass concentrations during the dry season over northern Thailand: Sensitivity to model aerosol chemical schemes and the effects on regional meteorology

Biomass burning emissions (agriculture and forest) are one of the major contributors to air pollution over Thailand during the hot-dry season (March–April) and aerosols from biomass burning can adversely affect the weather and produce health effects (respiratory disease, heart disease etc.). The present study investigated the sensitivity of aerosol chemistry schemes (Goddard Chemistry Aerosol Radiation and Transport, GOCART; Model for Simulating Aerosol Interactions and Chemistry, MOSAIC) on spatio-temporal distributions of simulated PM2.5 (particle sizes <2.5 μm) mass concentrations. Also, the study looked into the impact of PM2.5 on meteorology during an intense biomass burning period (15 March – 15 April 2019) using an online regional chemical transport model, Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). PM2.5 mass concentrations were observed over the northern regions of Thailand varying from 40 to 240 μg m−3. The simulations using GOCART and MOSAIC aerosol scheme were able to capture the spatio-temporal variations of PM2.5 mass concentrations in general. However, it underestimated the observation magnitudes by about 24% and 27%, respectively. In addition, the sensitivy of EDGAR-HTAP (Emission Database for Global Atmospheric Research collaboratively with the task force for Hemispheric Transport of Air Pollution) and CAMS-GLOB-ANT (Copernicus Atmosphere Monitoring Service Global) anthropogenic emission inventories on PM2.5 mass were investigated using the model. The simulated aerosol mass concentrations from EDGAR-HTAP found more realistic emissions when compared to CAMS-GLOB-ANT in most of the regions. The discrepancy in the simulation of aerosol mass concentrations could be attributed to uncertainties in the emission inventories, weak representation of secondary aerosol compositions, as well as the overestimation of wind speed and wet scavenging in the model. The study also investigated the influence of aerosols on meteorology by comparing a simulation with aerosol-radiation-interaction to a simulation without aerosol-radiation-interaction in the atmosphere during the time period. Significant changes in meteorological parameters were observed over regions having higher aerosol mass concentrations with a reduction of about 26% in solar insolation, 3.9% in near surface temperature, 21% in planetary boundary layer height and an increase of 13% in relative humidity.

Influence of aerosols on the meteorological regime of Northern Eurasia according to COSMO-Ru Model

We provided the estimation of the aerosols effect at the surface and at the top of the atmosphere, as well as on the sensible and latent heat flux for the Northern Eurasia using the MACv2 aerosol climatology. The numerical experiments were performed with the COSMO-Ru model for the January and July in 2017. It is found that the aerosol radiation effect on the surface can reach -50 W/m2. At the same time, it is shown that the net shortwave radiation increase does not unequivocally leads to the air temperature at two meters increase. We revealed that the temperature at 2 meters decreases on -0.5±0.1 degrees per 100 W/m2 in the clear sky condition for Mediterranean, Red, Black and Caspian seas areas. The temperature sensitivity is positive and equals 0.9±0.3 degrees per 100 W/m2 for Middle East and southern Europe and 1.7±0.7 degrees per 100 W/m2 for northern Africa.

Substantial global influence of anthropogenic aerosols on tropical cyclones over the past 40 years.

Over the past 40 years, anthropogenic aerosols have been substantially decreasing over Europe and the United States owing to pollution control measures, whereas they have increased in South and East Asia because of the economic and industrial growth in these regions. However, it is not yet clear how the changes in anthropogenic aerosols have altered global tropical cyclone (TC) activity. In this study, we reveal that the decreases in aerosols over Europe and the United States have contributed to significant decreases in TCs over the Southern Hemisphere as well as increases in TCs over the North Atlantic, whereas the increases in aerosols in South and East Asia have exerted substantial decreases in TCs over the western North Pacific. These results suggest that how society controls future emissions of anthropogenic aerosols will exert a substantial impact on the world’s TC activity.

Impact of Aerosol Radiative Effect on the Diurnal Cycle of Summer Precipitation Over North China: Distinct Results From Simulations With Parameterized Versus Explicit Convection

AbstractThe diurnal cycle of precipitation (DCP) is an important feature of local weather and climate. Owing to the complex interactions of aerosols and meteorological conditions, the influence of aerosols on the DCP is still inconclusive. Here we use regional modeling experiments with parameterized convection (PC) and explicit convection (EC) to disentangle the influence of aerosol radiative effects and model convection schemes on the DCP in North China, focusing on the precipitation peak time in the afternoon. We found that the EC experiments show delayed but more realistic DCPs compared with the PC experiments. With the increase of aerosol emissions, the PC experiments show delays in the afternoon precipitation peak, while this is not found in the EC experiments and observations. The different vertical velocities and vertical aerosol profiles produced by the schemes and the associated different thermodynamic responses are the primary reason for the distinct DCP responses.

Microbial communities in carbonate precipitates from drip waters in Nerja Cave, Spain.

Research on cave microorganisms has mainly focused on the microbial communities thriving on speleothems, rocks and sediments; however, drip water bacteria and calcite precipitation has received less attention. In this study, microbial communities of carbonate precipitates from drip waters in Nerja, a show cave close to the sea in southeastern Spain, were investigated. We observed a pronounced difference in the bacterial composition of the precipitates, depending on the galleries and halls. The most abundant phylum in the precipitates of the halls close to the cave entrance was Proteobacteria, due to the low depth of this sector, the direct influence of a garden on the top soil and the infiltration of waters into the cave, as well as the abundance of members of the order Hyphomicrobiales, dispersing from plant roots, and other Betaproteobacteria and Gammaproteobacteria, common soil inhabitants. The influence of marine aerosols explained the presence of Marinobacter, Idiomarina, Thalassobaculum, Altererythrobacter and other bacteria due to the short distance from the cave to the sea. Nineteen out of forty six genera identified in the cave have been reported to precipitate carbonate and likely have a role in mineral deposition.

Diagnostic markers of exacerbation of chronic obstructive pulmonary disease in workers exposed to industrial aerosols and tobacco

Introduction. Chronic obstructive pulmonary disease (COPD) is one of the most common occupational diseases registered in workers exposed to dust for a long time. This disease significantly worsens the quality of life, requires constant monitoring in the centers of occupational pathology and regular preventive measures. The proportion of COPD in the structure of occupational diseases has not changed significantly for decades, high rates of disability and premature mortality characterized this disease. The study aims to research the diagnostic parameters of COPD exacerbation under the influence of industrial aerosols and tobacco in the clinic of occupational diseases. Materials and methods. Researchers examined 153 patients with occupational COPD (toxic gases and inorganic dust). The comparison group consisted of 103 patients with smoking COPD. We established the diagnosis of COPD in accordance with the criteria of GOLD 2011. The duration of the study was 5 years. The authors conducted a complex of clinical and laboratory studies in all patients with an emphasis on the diagnostic parameters of COPD exacerbation and lung function. The critical significance level is p=0.05. Results. The development of occupational COPD under the influence of industrial aerosols and tobacco affects the frequency and predominant phenotype of exacerbations. Rare but severe exacerbations, mainly with eosinophilic type of inflammation, are present in COPD from the action of toxic gases. They respond well to therapy with systemic GCS. With COPD from the action of dust, hospitalization is not necessary for short-term exacerbations with neutrophilic type of inflammation, since such exacerbations respond to therapy with bronchodilators, and a significant proportion of exacerbations require the use of antibacterial therapy. Also, in COPD from the action of toxic gases, the experience of exposure to aerosols and gases of the production environment is an independent predictor of any exacerbations. But we do not have data on the significance of the length of service and the intensity of dust exposure. Conclusion. The risks of exacerbations of occupational COPD and the predicted features of their course depend on the etiological production factor, its intensity and duration of exposure. Clinical features determine different tactics of treatment and prevention of health deterioration. With the severity of COPD exacerbation from the action of toxic gases, symptoms of emphysema and hypoxemia are characteristic, with COPD from the action of dust, symptoms of bronchial obstruction, emphysema and hypoxemia are characteristic. Obtained results can use to construct risk meters of exacerbations and the scale of effectiveness of rehabilitation measures, to revise the standards of treatment and prevention of patients with COPD of professional genesis, as well as for the differential diagnosis of occupational obstructive pulmonary disease. Limitations. The study was conducted on the basis of Novosibirsk State Medical University and on the basis of the City Clinical Hospital No. 2. The limitations of the study may be the unidirectionality of the study performed and the small sample of patients participating in the research. Ethics. All patients have signed an informed consent form. The study program, the content of the informed consent, and the materials of the article were approved by the local ethics committee of Novosibirsk State Medical University and City Clinical Hospital No. 2.

Regional Signatures of Forced North Atlantic SST Variability: A Limited Role for Aerosols and Greenhouse Gases

AbstractPrior studies that argue external forcings drive Atlantic Multidecadal Variability (AMV) use linear detrending to remove the global warming trend from North Atlantic sea surface temperatures (SSTs). The linear detrending method, however, aliases residual nonlinear, global‐scale warming, affecting the interpretation of results. Here we revisit the role of external forcing in AMV using large climate model ensembles, examining the influences of greenhouse gases (GHGs) and industrial aerosols—the two dominant 20th‐century external forcing agents—on North Atlantic SSTs separately from their respective global response. Our approach shows that GHGs have little to no influence unique to the North Atlantic, while industrial aerosols exert only modest influences as part of a broader loading over the Northern Hemisphere. We demonstrate that a prominent role for external forcings on AMV is an artifact of the linear detrending method that disappears when their global responses common to the World Ocean are correctly accounted for.

Absorbing Aerosol Choices Influences Precipitation Changes Across Future Scenarios

AbstractFuture precipitation changes are controlled by the atmospheric energy budget, with temperature, water vapor, and absorbing aerosols playing dominant roles in driving radiative changes. Atmospheric energy budgets are calculated for different Shared Socioeconomic Pathways using ScenarioMIP projections from Phase 6 of the Climate Model Intercomparison Project and are used to quantify the influence of 21st century aerosol cleanup on precipitation. Absorbing aerosol influences on shortwave absorption are isolated from the effects of water vapor. Apparent hydrologic sensitivity is ∼40% higher for the Middle of the Road (SSP2‐4.5) scenario with aerosol cleanup than for the Regional Rivalry (SSP3‐7.0) scenario that maintains aerosol. Regionally, cleanup‐induced changes in the atmospheric energy budget are of a similar magnitude to the precipitation increases themselves and are larger than the influence of changes in atmospheric circulation. Policy choices about future absorbing aerosol emissions will therefore have major impacts on global and regional precipitation changes.

Little Influence of Asian Anthropogenic Aerosols on Summer Temperature in Central East Asia Since 1960

AbstractRecent summer surface air temperature (SAT) variations over Central East Asia (CEA) have been influenced by greenhouse gas and aerosol forcing since 1960. But how CEA SAT responds to contrasting changes in Asian, and European and North American aerosol sources remains unclear. By analyzing observations and model simulations, here we show that aerosol‐forced summer SAT changes over CEA since 1960 come mostly from the effects of aerosols outside Asia, with relatively small influences from Asian aerosols. Unlike Europe, where direct and indirect aerosol effects on surface solar radiation drive the SAT long‐term trend and decadal variations, over CEA atmospheric circulation response to aerosols outside Asia plays an important role. Aerosol‐forced anomalous low‐level low pressure in mid‐latitude Eurasia may influence the SAT anomalies downstream over mid‐latitude Asia, including a warm anomaly around CEA. The results suggest that caution is needed in attributing SAT changes around CEA to anthropogenic aerosols from Asia.