Observational evidence and mechanisms of aerosol effects on precipitation

Science Bulletin, Journal Year: 2024, Volume and Issue: 69(10), P. 1569 - 1580

Published: March 6, 2024

Language: Английский

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Trans-Pacific transport of dust aerosols from East Asia: Insights gained from multiple observations and modeling

Environmental Pollution, Journal Year: 2017, Volume and Issue: 230, P. 1030 - 1039

Published: July 27, 2017

Language: Английский

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Lightning enhancement over major oceanic shipping lanes

Geophysical Research Letters, Journal Year: 2017, Volume and Issue: 44(17), P. 9102 - 9111

Published: Sept. 7, 2017

Abstract Using 12 years of high‐resolution global lightning stroke data from the World Wide Lightning Location Network (WWLLN), we show that density is enhanced by up to a factor 2 directly over shipping lanes in northeastern Indian Ocean and South China Sea as compared adjacent areas with similar climatological characteristics. The enhancement most prominent during convectively active season, November–April for April–December Sea, has been detectable at least 2005 present. We hypothesize emissions aerosol particles precursors maritime vessel traffic lead microphysical convection storm electrification region lanes. These persistent localized anthropogenic perturbations otherwise clean regions are unique opportunity more thoroughly understand sensitivity deep particles.

Language: Английский

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Declining frequency of summertime local‐scale precipitation over eastern China from 1970 to 2010 and its potential link to aerosols

Geophysical Research Letters, Journal Year: 2017, Volume and Issue: 44(11), P. 5700 - 5708

Published: June 1, 2017

Abstract Summer precipitation plays critical roles in the energy balance and availability of fresh water over eastern China. However, little is known regarding trend local‐scale (LSP). Here we developed a novel method to determine LSP events summer afternoon throughout China from 1970 2010 based on hourly gauge measurements. The occurrence hours decrease at an annual rate 0.25%, which varies considerably by region, ranging 0.14% Yangtze River Delta 0.56% Pearl Delta. This declining frequency generally accompanied increase rain but visibility, whose linkage was investigated. In particular, more tended form when atmosphere slightly polluted. Afterward, suppressed. These findings have important implications for improving our understanding climatology daytime local scales.

Language: Английский

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Contrasting effects on deep convective clouds by different types of aerosols

Nature Communications, Journal Year: 2018, Volume and Issue: 9(1)

Published: Sept. 18, 2018

Convective clouds produce a significant proportion of the global precipitation and play an important role in energy water cycles. We quantify changes convective cloud ice mass-weighted altitude centroid (ZIWC) as function aerosol optical thickness (AOT). Analyses are conducted smoke, dust polluted continental environments over South America, Central Africa Southeast Asia, using latest measurements from CloudSat CALIPSO satellites. find aerosols can inhibit or invigorate convection, depending on type concentration. On average, smoke tends to suppress convection results lower ZIWC than clean clouds. Polluted promote higher ZIWC. The effects regionally dependent their signs differ place place. Moreover, we that inhibition invigoration do not vary monotonically with AOT variations depend strongly type. Our observational findings indicate is one key factors determining

Language: Английский

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Impact of low-pressure systems on winter heavy air pollution in the northwest Sichuan Basin, China

Atmospheric chemistry and physics, Journal Year: 2018, Volume and Issue: 18(18), P. 13601 - 13615

Published: Sept. 25, 2018

Abstract. The cities of Chengdu, Deyang, and Mianyang in the northwest Sichuan Basin are part a rapidly developing urban agglomeration adjoining eastern slopes Tibetan Plateau. Heavy air pollution events have frequently occurred over these recent decades, but effects meteorological conditions on unclear. We explored weather systems winter heavy from 1 January 2006 to 31 December 2012 2014 28 February 2017. A total 10 during research period 8 took place while region was affected by dry low-pressure system at 700 hPa. When front were controlled warm southerly flow, strong temperature inversion appeared above atmospheric boundary layer acting as lid. Forced this layer, local secondary circulation confined horizontal wind speed lower troposphere low. As result, vertical mixing dispersion atmosphere poor, favoring formation events. After had transited region, cold flow gradually dissipated, enhanced uplifted, also increased, resulting sharp decrease concentration pollutants. induced hPa thus played key role months agglomeration. This study provides scientific insights for forecasting China.

Language: Английский

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Estimating Summertime Precipitation from Himawari-8 and Global Forecast System Based on Machine Learning

IEEE Transactions on Geoscience and Remote Sensing, Journal Year: 2018, Volume and Issue: 57(5), P. 2557 - 2570

Published: Nov. 6, 2018

Random forests (RFs), an advanced machine learning (ML) method, was used here to develop a robust and rapid quantitative precipitation estimates (QPEs) algorithm for the new-generation geostationary satellite of Himawari-8. In this algorithm, global measurement (GPM) product has been employed train QPE prediction model. The real-time multiband infrared brightness temperature from Himawari-8, combined with spatiotemporally matched numerical weather (NWP) data forecast system, have as predictor variables QPE. Among in RF model, total precipitable water $K$ -index NWP highest rankings, indicating importance atmospheric environment To enhance accuracy models or optimize model training, sample-balance technique utilized adjust ratios samples nonprecipitation/precipitation classification regression sets. Further sensitivity validation analyses help determine optimal predicting pixel rain rate. selected is found predict area 0.87. For predicted product, mean-absolute-error root-mean-square error are 0.51 2.0 mm/h, respectively. Overall, ML higher detection rate over homogenous ocean surface compared land. Meanwhile, tends underestimate rate, especially presence heavy rainfall. Despite this, it still produces reasonable pattern rainfall intensity, which highly consistent GPM observations.

Language: Английский

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Two decades of satellite observations of AOD over mainland China using ATSR-2, AATSR and MODIS/Terra: data set evaluation and large-scale patterns

Atmospheric chemistry and physics, Journal Year: 2018, Volume and Issue: 18(3), P. 1573 - 1592

Published: Feb. 5, 2018

Abstract. The retrieval of aerosol properties from satellite observations provides their spatial distribution over a wide area in cloud-free conditions. As such, they complement ground-based measurements by providing information sparsely instrumented areas, albeit that significant differences may exist both the type obtained and temporal observations. In this paper, different types satellite-based instruments is used to provide 3-D climatology mainland China, i.e., vertical profiles extinction coefficients Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), lidar flying aboard Infrared Pathfinder Satellite Observation (CALIPSO) column-integrated (aerosol optical depth – AOD) available three radiometers: European Space Agency (ESA)'s Along-Track Scanning Radiometer version 2 (ATSR-2), Advanced (AATSR) (together referred as ATSR) NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) Terra satellite, together spanning period 1995–2015. AOD data are retrieved ATSR using dual view (ADV) v2.31 algorithm, while for MODIS Collection 6 (C6) set was merging AODs dark target (DT) deep blue (DB) algorithms, further DTDB merged product. These sets validated compared Aerosol Robotic Network (AERONET) L2.0 reference. results show that, slightly underestimates overestimates AOD. Consequently, overall lower than MODIS, difference increases increasing comparison also shows neither better other one everywhere. However, ADV has limitations bright surfaces which DB designed for. To allow C6 previous analyses where 5.1 (C5.1) were used, between C5.1 MODIS/Terra China briefly discussed. strong seasonal features vary latitude longitude across China. Two-decadal time series, averaged all presented Using 17 years basis follow evolution recent when environmental Envisat lost requires overlapping complementarity. precedes series 1995 2000 distinct increase period. two similar variations during 2011, minima maxima same years. extends beyond end 2012, showing decreasing

Language: Английский

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Aerosol-induced changes in the vertical structure of precipitation: a perspective of TRMM precipitation radar

Atmospheric chemistry and physics, Journal Year: 2018, Volume and Issue: 18(18), P. 13329 - 13343

Published: Sept. 19, 2018

Abstract. Our knowledge is still poor regarding the response of precipitation vertical structure to aerosols, partly due ignorance occurring at different spatial scales. A total 6 years collocated ground-based PM10 and satellite-based (Tropical Rainfall Measuring Mission, TRMM) radar data, along with ERA-Interim reanalysis, are used in this study investigate aerosol effects on three localized rain regimes (shallow, stratiform, convective rain) over Pearl River Delta region China. subjective analysis method proposed discriminate between synoptic-scale precipitations based weather composite charts where daily averaged wind field 850 hPa overlaid geopotential height 500 hPa. In general, average rate tends be greater under polluted conditions than clean conditions. But such potential regime dependent: as atmosphere becomes slightly (PM10≤38 µg m−3), top 1 % reflectivity (Z) for all initially increases, followed by continued increases weak decreases stratiform/shallow regimes, respectively. As much more polluted, dependences significant. From a perspective Z structure, comparisons (days highest third concentration) lowest show that exhibits deeper stronger pattern, whereas shallower weaker pattern observed stratiform shallow regimes. particular, 30 dBZ echo ∼29 (∼1.27 km) regime, but ∼10.8 (∼0.47 regime. However, no noticeable changes Impacts meteorological factors further studied both (RTH) center gravity Z, including velocity, shear, convection available energy, vertically integrated moisture flux divergence (MFD). The possible invigoration effect seems dependent good agreement previous findings. Overall, dependence supports notion or suppression cold warm adds new insights into nature complex interactions various

Language: Английский

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Intercomparison in spatial distributions and temporal trends derived from multi-source satellite aerosol products

Atmospheric chemistry and physics, Journal Year: 2019, Volume and Issue: 19(10), P. 7183 - 7207

Published: May 29, 2019

Abstract. Satellite-derived aerosol products provide long-term and large-scale observations for analysing distributions variations, climate-scale simulations, aerosol–climate interactions. Therefore, a better understanding of the consistencies differences among multiple is important. The objective this study to compare 11 global monthly optical depth (AOD) products, which are European Space Agency Climate Change Initiative (ESA-CCI) Advanced Along-Track Scanning Radiometer (AATSR), Very High Resolution (AVHRR), Multi-angle Imaging SpectroRadiometer (MISR), Moderate Spectroradiometer (MODIS), Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Visible Infrared (VIIRS), POLarization Directionality Earth's Reflectance (POLDER) products. AErosol RObotic NEtwork (AERONET) Version 3 Level 2.0 measurements at 308 sites around world selected comparison. Our results illustrate that spatial temporal variations most highly consistent globally but exhibit certain on regional site scales. In general, AATSR Dual View (ADV) SeaWiFS show lowest coverage with numerous missing values, while MODIS can cover areas (average 87 %) world. best performance observed in September–October–November (SON) worst June–July–August (JJA). All perform unsatisfactorily over northern Africa Middle East, southern eastern Asia, their coastal due influence from surface brightness human activities. agreement AERONET-based AOD values different scales all Furthermore, capture correct trends cases, especially where aerosols change significantly. capturing aerosols. These reference users select appropriate particular studies.

Language: Английский

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