Machine Learning for Fog-and-Low-Stratus Nowcasting from Meteosat SEVIRI Satellite Images

Atmosphere, Journal Year: 2023, Volume and Issue: 14(6), P. 953 - 953

Published: May 30, 2023

Fog and low stratus (FLS) are meteorological phenomena that have a significant impact on all ways of transportation public safety. Due to their similarity, they often grouped together as single category when viewed from satellite perspective. The early detection these is crucial reduce the negative effects can cause. This paper presents an image-based approach for short-term nighttime forecasting FLS during next 5 h over Morocco, based geostationary observations (Meteosat SEVIRI). To achieve this, dataset hourly night microphysics RGB product was generated native files covering cold season (October April) 5-year period (2016–2020). Two optical flow techniques (sparse dense) three deep learning (CNN, Unet ConvLSTM) were used, performance developed models assessed using mean squared error (MSE) structural similarity index measure (SSIM) metrics. Hourly Meteorological Aviation Routine Weather Reports (METAR) Morocco used qualitatively compare existence in METAR, where it also shown by product. Results analysis show outperform traditional method with SSIM MSE about 0.6 0.3, respectively. Deep promising results first hours. However, highly dependent number filters computing resources, while sparse found be very sensitive mask definition target phenomenon.

Language: Английский

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Statistical and spatial analysis of air pollution in the cities of Abha and Bisha in the Kingdom of Saudi Arabia

Alexandria Engineering Journal, Journal Year: 2023, Volume and Issue: 79, P. 227 - 236

Published: Aug. 12, 2023

The Kingdom of Saudi Arabia has experienced a notable impact as result population growth. Consequently, there is heightened concern regarding urban air pollution and its effects on both individuals society. This issue great importance in the development expansion cities within region. presence pollutants been linked to various negative health outcomes, including diseases, allergic reactions, even fatalities humans. Additionally, can have detrimental other living organisms, such animals food crops, also cause harm natural environment, contributing climate change, ozone depletion, land degradation areas. present study employs statistical analysis regulate spatial theory examine areas Bisha Abha Arabia. results showed that carbon emissions are lower than Bisha. shows no from factories located outside reach cities. research findings indicate significant differences at significance level 0.05 terms mean responses participants favored Abha, with concerning was 0.005. In addition aforementioned results, conclusions recommendations were derived investigation.

Language: Английский

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Classification of Cloud Phase Using Combined Ground-Based Polarization Lidar and Millimeter Cloud Radar Observations Over the Tibetan Plateau

IEEE Transactions on Geoscience and Remote Sensing, Journal Year: 2023, Volume and Issue: 61, P. 1 - 13

Published: Jan. 1, 2023

The distributions of cloud phases play an important role in influencing the weather and climate system. characteristics clouds above Tibetan Plateau (TP) can profoundly affect regional global atmospheric circulation. To research TP region, a retrieval algorithm was developed based on combination polarization lidar millimeter radar measurements applied to data from comprehensive field campaign central summer 2014. structure phase four different types were retrieved accordingly, which validates reliability algorithm. result shows that occurrence frequency low remains around 50%, is very high throughout whole day Nagqu, summer. liquid mixed frequencies are higher morning afternoon, while ice mainly occurs afternoon midnight. Liquid show inverse relationship layer 2 8 km height. Meanwhile, proportion top significantly than body, indicates supercooled water more likely appear at cloud. fractional probabilities total intersect about $-26.7\,\,^{\circ }\text{C}$ .

Language: Английский

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Surface Radiative Forcing as a Climate-Change Indicator in North India due to the Combined Effects of Dust and Biomass Burning

Fire, Journal Year: 2023, Volume and Issue: 6(9), P. 365 - 365

Published: Sept. 19, 2023

This study estimates the radiative forcing by biomass burning and dust aerosols over Indian subcontinent, with emphasis on Indo-Gangetic Plains (IGP) during period from January 2021 to April 2021, based multiple satellite reanalysis datasets. In this respect, we used retrievals Moderate Resolution Spectroradiometer (MODIS) Cloud-Aerosol Lidar Infrared Pathfinder Satellite Observation (CALIPSO) system, as well data Goddard Earth Observing System, version 5 (GEOS-5), Modern-Era Retrospective analysis for Research Applications, 2 (MERRA-2), Copernicus Atmosphere Monitoring Service (CAMS), ERA-Interim. According MERRA-2 CAMS, highest black carbon (BC) concentrations in were 7–8 µg m−3, which significantly lower than measurements performed main cities along IGP, such Patiala, Delhi, Kanpur. The meteorological accompanied CALIPSO lidar showed that vertical distribution of total attenuated backscatter (TAB) could reach altitudes up ~4–5 km be transported central Himalayan region. spatial-averaged daily aerosol (ARF) values subcontinent found range −51.40 −6.08 W m−2 (mean −22.02 ± 9.19 m−2), while a monthly basis, ARF varied widely, −146.24 −1.63 −45.56 22.85 m−2) different parts Furthermore, BC ranged −2.23 −0.35 (−1.01 0.40 it −15.29 −0.31 (−2.46 2.32 regions southern Asia, indicating rather small contribution effect large presence highly scattering aerosols. Our findings highlight importance growing burning, light recent climate change rapid decline air quality North India Ocean.

Language: Английский

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Effect of the boundary layer low-level jet on fast fog spatial propagation

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(21), P. 13987 - 14002

Published: Nov. 9, 2023

Abstract. The spatiotemporal variation of fog reflects the complex interactions among fog, boundary layer thermodynamics and synoptic systems. Previous studies revealed that can present a fast spatial propagation feature attribute it to low-level jet (BLLJ), but effect BLLJ on is not quantitatively understood. Here we analyze large-scale event in Jiangsu, China, from 20 21 January 2020. Satellite retrievals show propagates southeast coastal area northwest inland with speed 9.6 m s−1, which 3 times larger than ground wind speeds. meteorologies are insufficient explain propagation, further investigated by Weather Research Forecasting model (WRF) simulations. could be attributed occurring between 50 500 m, because speeds (10 s−1) directions (southeast) core consistent propagation. Through sensitive experiments process analysis, three possible mechanisms revealed: (1) abundant oceanic moisture transported inland, increasing humidity promoting condensation; (2) warm air enhancing inversion favoring accumulation; (3) advection probably promotes low-stratus formation, later subsides become turbulent mixing droplets. would decrease notably 6.4 s−1 (66 %) if BLLJ-related advections were turned off.

Language: Английский

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