Long-term variations of AOD from an AERONET station in the central Arabian Peninsula

Maghrabi, Abdullrahman; Alotaibi, R. N.

doi:10.1007/s00704-017-2328-x

Cited by 24 publications

(13 citation statements)

References 33 publications

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“…The Sen's statistic gives a robust estimation of trend and is based on the median slope of each point-pair slope in a dataset, hence fairly resistant to outliers. Similarly, the Mann-Kendall test is simple and robust against outliers and missing values as well as distribution free and has the high power for non-normal distributed data [72,[83][84][85][86][87][88][89][90][91]. It is worth mentioning that the modified version of Mann-Kendall (m-MK) test was used which has the ability to nullify the effect of autocorrelation prior to determination of statistical significance.…”

Section: Methodsmentioning

confidence: 99%

“…Further, statistical significance of the AOD annual and seasonal time series at 95% confidence level was determined. The governing equations for statistical tests can be found in the work done by a number of researchers including [85,[93][94][95][96][97]. In order to find a possible dependence of AOD trends upon rainfall and temperature, trends in multi-year annual and seasonal mean rainfall and temperature during the study period were calculated for the selected regions.…”

Section: Methodsmentioning

confidence: 99%

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Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters

et al. 2020

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Aerosol optical depth (AOD) has become one of the most crucial parameters for climate change assessment on regional and global scales. The present study investigates trends in AOD using long-term data derived from moderate resolution imaging spectro-radiometer (MODIS) over twelve regions in Pakistan. Different statistical tests are used to assess the annual and seasonal trends in AOD. Results reveal increasing AOD trends over most of the selected regions with an obvious increase over the north and northeastern parts of the study area. Annually, increasing trends (0.0002–0.0047 year−1) were observed over seven regions, with three being statistically significant. All the selected regions experience increasing AOD trends during the winter season with six being statistically significant while during the summer season seven regions experience increasing AOD trends and the remaining five exhibit the converse with two being statistically significant. The changes in the sign and magnitude of AOD trends have been attributed to prevailing meteorological conditions. The decreasing rainfall and increasing temperature trends mostly support the increasing AOD trend over the selected regions. The high/low AOD phases during the study period may be ascribed to the anomalies in mid-tropospheric relative humidity and wind fields. The summer season is generally characterized by high AOD with peak values observed over the regions located in central plains, which can be attributed to the dense population and enhanced concentration of industrial and vehicular emissions over this part of the study area. The results derived from the present study give an insight into aerosol trends and could form the basis for aerosol-induced climate change assessment over the study area.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters

et al. 2020

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“…In Saudi Arabia, economic and industrial development has led to an increase in anthropogenic emissions and has enhanced the aerosol concentration [32]. Moreover, a considerable portion of its territory comprises deserts and semi-deserts, which predetermines an increased intensity of exposure to the atmospheric aerosols that critically affect the life and health of its residents [15,18,[33][34][35][36]. There is no effective way to prevent and/or reduce the negative social impacts of atmospheric aerosols in Saudi Arabia.…”

Section: Introductionmentioning

confidence: 99%

Study on Vertically Distributed Aerosol Optical Characteristics over Saudi Arabia Using CALIPSO Satellite Data

Zhang

Chen

et al. 2022

Applied Sciences

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The optical characteristics of vertically distributed aerosols over Saudi Arabia were investigated using the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data from 2007 to 2019. The study region was divided into three parts (Region I: Tabuk, Makkah, Al Madinah, Asir, Al Bahah, Jizan, Riyadh, Mecca, Medina, the eastern region, Kassim, Hale, Asir, Baha, Tabuk, the northern border region, Jizan, Najilan, and Jufu. Region II: Ar, Al, Ha, Al, and Najran. Region III Al Hudud ash Shamaliyah and Ash Sharqiyah) to understand regional aerosol characteristics by performing interannual and seasonal analysis for nine aerosol types during the day and nighttime. We found that the aerosol optical depth (AOD) estimates were the highest over eastern Saudi Arabia (region III) and were seemingly driven by the presence of an expansive desert in the region. As anticipated, the AOD observations were substantially higher in spring and summer than in autumn and winter owing to the frequent occurrence of dust events during the former. Daytime observations exhibited higher AOD values than those at nighttime, which might be related to higher daytime anthropogenic activities. The estimates of the base height of the lowest aerosol layer (HB1) and the top altitude of the highest aerosol layer (TAH) were altered depending on the topography (the higher the altitude, the higher the annual mean value of HB1 and TAH). The aerosol layers (N) were relatively abundant over region III, seemingly due to the relatively stronger atmospheric convection over this region. The volume depolarization ratio of the lowest aerosol layer (VDR1) was considerable during the night due to deposition at nighttime, and VDR1 was relatively substantial in spring and summer. The color ratio of the lowest aerosol layer (CR1) estimates over regions II and III was higher at night. We report a weak positive correlation between the thickness of the lowest aerosol layer (HTH1) and the AOD of the lowest aerosol layer (AOD1) in the three regions, a strong positive correlation between TAH and N, and a negative correlation between the AOD proportion of the lowest aerosol layer (PAOD1) and N in Saudi Arabia. In this paper, the optical and physical properties of aerosols in Saudi Arabia have been studied for 13 years. Our results could provide references for researchers and the government, and relevant departments with data support on the aerosol layer to help control air pollution in Saudi Arabia.

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“…Atmospheric aerosols are considered as an important parameter of the Earth's atmospheric system. Absorption and scattering are the two main physical processes that are associated with the interaction of aerosol particles with both solar and long-wave radiation [e.g., [1][2]. They, also, affect cloud properties and composition processes, which therefore impact the Earth's radiative budget [3][4].…”

Section: Introductionmentioning

confidence: 99%

“…They, also, affect cloud properties and composition processes, which therefore impact the Earth's radiative budget [3][4]. Aerosol Optical Depth (AOD) measures the extinction of a monochromatic light beam through a given aerosol layer and considered as one of most important parameters in characterizing the aerosols radiative forcing at the surface and at the top of the atmosphere [2,5]. Primary cosmic rays are high-energy particles persistently bombarding the Earth's atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Correlation analysis between the Aerosol Optical Depth and Cosmic Rays

Maghrabi¹,

Kudela²

2019

Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)

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In this study, aerosol optical depth (AOD870 nm) data, for the period between 1999 to 2015 obtained from the solar village AERONET site (central Saudi Arabia); have been correlated with cosmic ray (CR) data from Oulu neutron monitor. Positive and significant correlation between the two variables has been found. Moreover, power spectral analyses using the Fourier Transform (FT) technique have been carried out to investigate the periodicities in both the CR and AOD time series. Several common periodicities between the two variables have been recognized indicating possible mutual relation between variations of aerosols and of CR intensity observed on the ground.

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Long-term variations of AOD from an AERONET station in the central Arabian Peninsula

Cited by 24 publications

References 33 publications

Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters

Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters

Study on Vertically Distributed Aerosol Optical Characteristics over Saudi Arabia Using CALIPSO Satellite Data

Correlation analysis between the Aerosol Optical Depth and Cosmic Rays

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