Aerosol and boundary-layer interactions and impact on air quality

National Science Review, Journal Year: 2017, Volume and Issue: 4(6), P. 810 - 833

Published: Sept. 16, 2017

Abstract Air quality is concerned with pollutants in both the gas phase and solid or liquid phases. The latter are referred to as aerosols, which multifaceted agents affecting air quality, weather climate through many mechanisms. Unlike pollutants, aerosols interact strongly meteorological variables strongest interactions taking place planetary boundary layer (PBL). PBL hosting bulk of lower atmosphere affected by aerosol radiative effects. Both scattering absorption reduce amount solar radiation reaching ground thus sensible heat fluxes that drive diurnal evolution PBL. Moreover, can increase atmospheric stability inducing a temperature inversion result radiation, suppresses dispersion leads further increases concentration Such positive feedback especially strong during severe pollution events. Knowledge crucial for understanding between meteorology. A key question how interacts vertical directions, affects quality. We review major advances measurements, processes their each other complex mechanisms, highlight priorities future studies.

Language: Английский

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Aerosol and monsoon climate interactions over Asia

Reviews of Geophysics, Journal Year: 2016, Volume and Issue: 54(4), P. 866 - 929

Published: Sept. 10, 2016

Abstract The increasing severity of droughts/floods and worsening air quality from aerosols in Asia monsoon regions are the two gravest threats facing over 60% world population living Asian regions. These dual have fueled a large body research last decade on roles impacting weather climate. This paper provides comprehensive review studies aerosols, monsoons, their interactions. region is primary source emissions diverse species both anthropogenic natural origins. distributions aerosol loading strongly influenced by distinct climatic regimes, which are, turn, modulated effects. On continental scale, reduce surface insolation weaken land‐ocean thermal contrast, thus inhibiting development monsoons. Locally, radiative effects alter thermodynamic stability convective potential lower atmosphere leading to reduced temperatures, increased atmospheric stability, weakened wind circulations. state, determines formation clouds, convection, precipitation, may also be altered serving as cloud condensation nuclei or ice nuclei. Absorbing such black carbon desert dust induce dynamical feedback processes, strengthening early affecting subsequent evolution monsoon. Many mechanisms been put forth regarding how modulate amplitude, frequency, intensity, phase different climate variables. A wide range theoretical, observational, modeling findings monsoon, interactions synthesized. new paradigm proposed investigating aerosol‐monsoon interactions, dust, biomass burning, biogenic vegetation considered integral components an intrinsic system, subject external forcing global warming, land use change. Future calls for integrated approach international collaborations based long‐term sustained observations, process measurements, improved models, well using observations constrain model simulations projections.

Language: Английский

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The climatology of planetary boundary layer height in China derived from radiosonde and reanalysis data

Atmospheric chemistry and physics, Journal Year: 2016, Volume and Issue: 16(20), P. 13309 - 13319

Published: Oct. 28, 2016

Abstract. The important roles of the planetary boundary layer (PBL) in climate, weather and air quality have long been recognized, but little is known about PBL climatology China. Using fine-resolution sounding observations made across China reanalysis data, we conducted a comprehensive investigation from January 2011 to July 2015. height (BLH) found be generally higher spring summer than that fall winter. comparison seasonally averaged BLHs derived reanalysis, on average, shows good agreement, despite pronounced inconsistence some regions. BLH, soundings three or four times daily summer, tends peak early afternoon, diurnal amplitude BLH northern western subregions other subregions. meteorological influence annual cycle investigated as well, showing at most sites negatively associated with surface pressure lower tropospheric stability, positively near-surface wind speed temperature. In addition, cloud suppress development PBL, particularly afternoon. This indicates meteorology plays significant role processes. Overall, key findings obtained this study lay solid foundation for us gain deep insight into fundamentals China, which helps understand pollution, climate

Language: Английский

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Advances in understanding large‐scale responses of the water cycle to climate change

Annals of the New York Academy of Sciences, Journal Year: 2020, Volume and Issue: 1472(1), P. 49 - 75

Published: April 4, 2020

Abstract Globally, thermodynamics explains an increase in atmospheric water vapor with warming of around 7%/°C near to the surface. In contrast, global precipitation and evaporation are constrained by Earth's energy balance at ∼2–3%/°C. However, this rate is suppressed rapid adjustments response greenhouse gases absorbing aerosols that directly alter budget. Rapid forcings, cooling effects from scattering aerosol, observational uncertainty can explain why observed responses currently difficult detect but expected emerge accelerate as increases aerosol forcing diminishes. Precipitation be smaller over land than ocean due limitations on moisture convergence, exacerbated feedbacks affected adjustments. Thermodynamic fluxes amplify wet dry events, driving intensification extremes. The deviate a simple thermodynamic in‐storm larger‐scale feedback processes, while changes large‐scale dynamics catchment characteristics further modulate frequency flooding increases. Changes circulation radiative evolving surface temperature patterns capable dominating cycle some regions. Moreover, direct impact human activities through abstraction, irrigation, use change already significant component regional importance demand grows population.

Language: Английский

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East Asian Study of Tropospheric Aerosols and their Impact on Regional Clouds, Precipitation, and Climate (EAST‐AIR_CPC)

Journal of Geophysical Research Atmospheres, Journal Year: 2019, Volume and Issue: 124(23), P. 13026 - 13054

Published: Oct. 23, 2019

Abstract Aerosols have significant and complex impacts on regional climate in East Asia. Cloud‐aerosol‐precipitation interactions (CAPI) remain most challenging studies. The quantitative understanding of CAPI requires good knowledge aerosols, ranging from their formation, composition, transport, radiative, hygroscopic, microphysical properties. A comprehensive review is presented here centered the based chiefly, but not limited to, publications special section named EAST‐AIRcpc concerning (1) observations aerosol loading properties, (2) relationships between aerosols meteorological variables affecting CAPI, (3) mechanisms behind (4) quantification impact climate. Heavy Asia has radiative effects by reducing surface radiation, increasing air temperature, lowering boundary layer height. key factor absorption, which particularly strong central China. This absorption can a wide range such as creating an imbalance forcing at top bottom atmosphere, leading to inconsistent retrievals cloud space‐borne ground‐based instruments. Aerosol delay or suppress initiation development convective clouds whose microphysics be further altered effect aerosols. For same thickness, likelihood precipitation influenced aerosols: suppressing light rain enhancing heavy rain, delaying intensifying thunderstorms, onset isolated showers parts Rainfall become more inhomogeneous extreme heavily polluted urban regions.

Language: Английский

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Impact of diurnal variability and meteorological factors on the PM2.5 - AOD relationship: Implications for PM2.5 remote sensing

Environmental Pollution, Journal Year: 2016, Volume and Issue: 221, P. 94 - 104

Published: Nov. 23, 2016

PM2.5 retrieval from space is still challenging due to the elusive relationship between and aerosol optical depth (AOD), which further complicated by meteorological factors. In this work, we investigated diurnal cycle of in China, using ground-based PM measurements obtained at 226 sites China Atmosphere Watch Network during period January 2013 December 2015. Results showed that nearly half witnessed a maximum morning, contrast least frequent occurrence (5%) afternoon when strong solar radiation received surface results rapid vertical diffusion aerosols thus lower mass concentration. tends peak equally morning evening North Plain (NCP) with an amplitude twice or three times Pearl River Delta (PRD), whereas dominates Yangtze (YRD) magnitude lying those NCP PRD. The gridded correlation maps reveal varying correlations around each site, depending on locations seasons. Concerning impact variation correlation, averaging schemes 3-h, 5-h, 24-h time windows tend have larger R biases, compared scheme 1-h window, indicating plays significant role establishment explicit AOD. addition, high cloud fraction relative humidity weaken regardless geographical location. Therefore, meteorology could be one most plausible alternatives explaining values observed, its non-negligible effect MODIS AOD retrievals. Our findings implications for remote sensing, as long cycle, along meteorology, are explicitly considered future.

Language: Английский

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Point-surface fusion of station measurements and satellite observations for mapping PM2.5 distribution in China: Methods and assessment

Atmospheric Environment, Journal Year: 2017, Volume and Issue: 152, P. 477 - 489

Published: Jan. 5, 2017

Language: Английский

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Shift in the Temporal Trend of Boundary Layer Height in China Using Long‐Term (1979–2016) Radiosonde Data

Geophysical Research Letters, Journal Year: 2019, Volume and Issue: 46(11), P. 6080 - 6089

Published: May 24, 2019

Abstract The knowledge regarding how the boundary layer height (BLH) changes over time is still poor. Here we analyze spatial and temporal in radiosonde‐derived measurements of BLH China from 1979 to 2016. A qualitatively robust abrupt change occurred 2004. Over former period (from 2003) a spatially uniform increase was found BLH, while latter decreased nonuniform way. Second, meteorological influence on rising determined have negative association with soil moisture, lower tropospheric stability relative humidity, positive near‐surface temperature. Yet, there different meteorology period, where revealed T sfc humidity. These findings shed new light long‐term air pollution across China.

Language: Английский

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Analysis of influential factors for the relationship between PM<sub>2.5</sub> and AOD in Beijing

Atmospheric chemistry and physics, Journal Year: 2017, Volume and Issue: 17(21), P. 13473 - 13489

Published: Nov. 13, 2017

Abstract. The relationship between aerosol optical depth (AOD) and PM2.5 is often investigated in order to obtain surface from satellite observation of AOD with a broad area coverage. However, various factors could affect the AOD–PM2.5 regressions. Using both ground observations Beijing 2011 2015, this study analyzes influential including type, relative humidity (RH), planetary boundary layer height (PBLH), wind speed direction, vertical structure distribution. ratio AOD, which defined as η, square their correlation coefficient (R2) have been examined. It shows that η varies 54.32 183.14, 87.32 104.79, 95.13 163.52, 1.23 235.08 µg m−3 type spring, summer, fall, winter, respectively. smaller for scattering-dominant aerosols than absorbing-dominant aerosols, coarse-mode fine-mode aerosols. Both RH PBLH value significantly. higher RH, PBLH, η. For data correction compared those without, R2 monthly averaged at 14:00 LT increases 0.63 0.76, multi-year by time day 0.01 0.93, 0.24 0.84, 0.85 0.91, 0.84 0.93 four seasons Wind direction key factor transport spatial–temporal distribution originated different sources distinctive physicochemical characteristics. Similar variation PM2.5, also decreases increasing speed, indicating contribution concentrations speed. exhibits remarkable change seasons, most particles concentrated within about 500 m summer 150 winter. Compared whole atmosphere, below has better 0.77. This suggests all above should be considered when we investigate relationships.

Language: Английский

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Clean heating during winter season in Northern China: A review

Renewable and Sustainable Energy Reviews, Journal Year: 2021, Volume and Issue: 149, P. 111339 - 111339

Published: July 6, 2021

Language: Английский

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