Investigating the Aerosol Optical Depth and Angstrom Exponent and Their Relationships with Meteorological Parameters Ove
- PDF / 1,174,769 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 42 Downloads / 206 Views
RESEARCH ARTICLE
Investigating the Aerosol Optical Depth and Angstrom Exponent and Their Relationships with Meteorological Parameters Over Lahore in Pakistan Salman Tariq1
•
Zia ul-Haq1
Received: 19 March 2015 / Revised: 14 November 2018 / Accepted: 18 December 2018 The National Academy of Sciences, India 2019
Abstract In the present work, AERONET (AErosol RObotic NETwork) data of 2006–2014 have been used to analyze the variations in aerosol optical depth (AOD) at 500 nm and Angstrom exponent (440/870) (AE). In order to have an in-depth knowledge of aerosol variability, we have analyzed the association of aerosol properties with the meteorological parameters such as temperature, mean sea level pressure, rainfall, dew point, and dust storm frequency. Long-term observations of MODIS-AOD are also validated with AERONET-AOD over Lahore. The peak monthly mean value of AOD is found in July (1.00 ± 0.34) with the corresponding AE value of 0.85 ± 0.29 pointing toward the fact that desert/soil dust aerosols dominated the atmosphere of Lahore. The lowest value of AOD is found in February (0.47 ± 0.26) with the corresponding AE value of 1.22 ± 0.29 representing the presence of urban/ industrial aerosols in the atmosphere over Lahore. The monthly mean AE value is found to be maximum in January (1.36 ± 0.15), whereas lowest value of AE is found in June (0.55 ± 0.25). AOD shows positive correlations with temperature, dew point, relative humidity, visibility, rain and dust storm frequency, and negative with mean sea level pressure and wind speed. AE exhibits positive correlations with relative humidity and mean sea level pressure, while with temperature, dew point, visibility, rain and dust storm frequency, it shows negative correlations.
& Salman Tariq [email protected] 1
Remote Sensing and GIS Group, Department of Space Science, University of the Punjab, New-Campus, Lahore 54590, Pakistan
Keywords Aerosol optical depth Angstrom exponent Meteorological parameters Lahore
1 Introduction The earth’s atmosphere contains microscopic particles known as aerosols that affect the climate and the atmosphere, lithosphere, hydrosphere and biosphere [1]. They are found in a variety of forms and sizes. Their chemical and physical characteristics are highly variable. Aerosols originate from two kinds of sources: one is natural and the other is anthropogenic. Observations of aerosol properties reduce uncertainties in climate modeling [2–4]. Due to largely scattered sources, optical properties of aerosols vary with space and time [5]. Satellite remote sensing monitors the aerosol effects on climate and its characterization [6], but ground-based remote sensing gives accurate and valid information about the optical properties of aerosols. We have used sun photometer (by CIMEL) data from Aerosol Robotic Network (AERONET), a ground-based remote sensing instrument [7]. Various studies have been done on changes in aerosol properties with meteorological parameters such as temperature, wind speed, humidity and visibility [8–10].
Data Loading...
