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Liaqut A, Tariq S, Younes I. A study on optical properties, classification, and transport of aerosols during the smog period over South Asia using remote sensing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:69096-69121. [PMID: 37129820 DOI: 10.1007/s11356-023-27047-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Over the past few years, South Asian region has experienced frequent and thick smog events because of rapid population growth and enhanced anthropogenic activities, particularly in the Indo-Gangetic Plain (IGP). Therefore, the present study investigates aerosol properties such as aerosol optical depth (AOD) (500 nm), Angstrom exponent (AE) (440-870 nm), single scattering albedo (SSA), fine-mode fraction (FMF), absorption aerosol optical depth (AAOD), and absorption aerosol exponent (AAE) over selected AERONET sites namely Bhola (2012-2021), Dhaka (2012-2021), Jaipur (2011-2021), Kanpur (2011-2021), Karachi (2011-2021), Lahore (2011-2021), and Pokhara (2011-2021) in the IGP during the smog period (October, November, and December). Additionally, different aerosol types were categorized using AERONET direct sun (AOD, AE) and inversion products (VSD, SSA, RI, FMF, and ASY). The monthly mean AOD, AE, and FMF varied from ⁓0.33 to 1.07, ⁓0.3 to 1.4, and 0.6-0.9 µm over all selected AERONET sites during the smog period. Moreover, the outcomes revealed the dominance of biomass-burning and urban/ industrial aerosols over Lahore, Karachi, Dhaka, and Bhola during the smog period. Contrary to this, dust and mixed aerosols were abundant over Jaipur and Karachi, respectively. Furthermore, HYSPLIT cluster analysis is used to trace the transmission paths and potential sources of aerosols over selected sites.
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Affiliation(s)
- Anum Liaqut
- Department of Geography, University of the Punjab, Lahore, Pakistan.
| | - Salman Tariq
- Remote Sensing, GIS and Climatic Research Lab (National Center of GIS and Space Application), University of the Punjab, Lahore, Pakistan
- Department of Space Science, University of the Punjab, Lahore, Pakistan
| | - Isma Younes
- Department of Geography, University of the Punjab, Lahore, Pakistan
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Thomas BC, Neale PJ, Snyder BR. Solar irradiance changes and photobiological effects at earth's surface following astrophysical ionizing radiation events. ASTROBIOLOGY 2015; 15:207-220. [PMID: 25692406 DOI: 10.1089/ast.2014.1224] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In this work, we employed the Tropospheric Ultraviolet and Visible (TUV) radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light) for clear-sky conditions and fixed aerosol parameter values. We also considered a wide range of biological effects on organisms ranging from humans to phytoplankton. We found that past work overestimated UVB irradiance but that relative estimates for increase in exposure to DNA-damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in very limited geographical areas; instead we found a net increase for most of the modeled time-space region. This result has implications for proposed climate changes associated with ionizing radiation events.
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Affiliation(s)
- Brian C Thomas
- 1 Department of Physics and Astronomy, Washburn University , Topeka, Kansas
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Bais AF, McKenzie RL, Bernhard G, Aucamp PJ, Ilyas M, Madronich S, Tourpali K. Ozone depletion and climate change: impacts on UV radiation. Photochem Photobiol Sci 2015; 14:19-52. [DOI: 10.1039/c4pp90032d] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Percentage changes in the UV Index (UVI) for 2090 relative to 2015 due to changes in ozone (left) and aerosols (right) only. Large decreases are projected over Antarctica due to stratospheric ozone recovery. Increases are projected for parts of Asia due to decreases in aerosols, partly reversing the possible large reductions in UVI after the 1950s.
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Affiliation(s)
- A. F. Bais
- Laboratory of Atmospheric Physics
- Aristotle University of Thessaloniki
- 54124 Thessaloniki
- Greece
| | - R. L. McKenzie
- National Institute of Water and Atmospheric Research
- PB 50061 Omakau, Central Otago
- New Zealand
| | | | - P. J. Aucamp
- Ptersa Environmental Management Consultants
- Faerie Glen
- South Africa
| | - M. Ilyas
- School of Environmental Engineering
- University Malaysia Perlis
- Kangar
- Malaysia
| | - S. Madronich
- National Center for Atmospheric Research
- Boulder
- USA
| | - K. Tourpali
- Laboratory of Atmospheric Physics
- Aristotle University of Thessaloniki
- 54124 Thessaloniki
- Greece
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Lee KH, Li Z, Cribb MC, Liu J, Wang L, Zheng Y, Xia X, Chen H, Li B. Aerosol optical depth measurements in eastern China and a new calibration method. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd012812] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kouremeti N, Bais A, Kazadzis S, Blumthaler M, Schmitt R. Charge-coupled device spectrograph for direct solar irradiance and sky radiance measurements. APPLIED OPTICS 2008; 47:1594-1607. [PMID: 18382591 DOI: 10.1364/ao.47.001594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The characterization of a charged-coupled device (CCD) spectrograph developed at the Laboratory of Atmospheric Physics, Thessaloniki is presented. The absolute sensitivity of the instrument for direct irradiance and sky radiance measurements was determined, respectively, with an uncertainty of 4.4% and 6.6% in the UV-B, and 3% and 6% in the UV-A, visible and near-infrared (NIR) wavelength ranges. The overall uncertainty associated with the direct irradiance and the sky radiance measurements is, respectively, of the order of 5% and 7% in the UV-B, increasing to 10% for low signals [e.g., at solar zenith angles (SZAs) larger than 70 degrees ], and 4% and 6% in the UV-A, visible, and NIR. Direct solar spectral irradiance measurements from an independently calibrated spectroradiometer (Bentham DTM 300) were compared with the corresponding CCD measurements. Their agreement in the wavelength range of 310-500nm is within 0.5% +/- 1.1% (for SZA between 20 degrees and 70 degrees ). Aerosol optical depth (AOD) derived by the two instruments using direct Sun spectra and by a collocated Cimel sunphotometer [Aerosol Robotic network (AERONET)] agree to within 0.02 +/- 0.02 in the range of 315-870 nm. Significant correlation coefficients with a maximum of 0.99 in the range of 340-360 nm and a minimum of 0.90 at 870 nm were found between synchronous AOD measurements with the Bentham and the Cimel instruments.
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Affiliation(s)
- Natalia Kouremeti
- Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Taylor TE, L'Ecuyer TS, Slusser JR, Stephens GL, Goering CD. An operational retrieval algorithm for determining aerosol optical properties in the ultraviolet. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd008661] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lee KH, Li Z, Wong MS, Xin J, Wang Y, Hao WM, Zhao F. Aerosol single scattering albedo estimated across China from a combination of ground and satellite measurements. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jd009077] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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McKenzie RL, Aucamp PJ, Bais AF, Björn LO, Ilyas M. Changes in biologically-active ultraviolet radiation reaching the Earth's surface. Photochem Photobiol Sci 2007; 6:218-31. [PMID: 17344959 DOI: 10.1039/b700017k] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The Montreal Protocol is working. Concentrations of major ozone-depleting substances in the atmosphere are now decreasing, and the decline in total column amounts seen in the 1980s and 1990s at mid-latitudes has not continued. In polar regions, there is much greater natural variability. Each spring, large ozone holes continue to occur in Antarctica and less severe regions of depleted ozone continue to occur in the Arctic. There is evidence that some of these changes are driven by changes in atmospheric circulation rather than being solely attributable to reductions in ozone-depleting substances, which may indicate a linkage to climate change. Global ozone is still lower than in the 1970s and a return to that state is not expected for several decades. As changes in ozone impinge directly on UV radiation, elevated UV radiation due to reduced ozone is expected to continue over that period. Long-term changes in UV-B due to ozone depletion are difficult to verify through direct measurement, but there is strong evidence that UV-B irradiance increased over the period of ozone depletion. At unpolluted sites in the southern hemisphere, there is some evidence that UV-B irradiance has diminished since the late 1990s. The availability and temporal extent of UV data have improved, and we are now able to evaluate the changes in recent times compared with those estimated since the late 1920s, when ozone measurements first became available. The increases in UV-B irradiance over the latter part of the 20th century have been larger than the natural variability. There is increased evidence that aerosols have a larger effect on surface UV-B radiation than previously thought. At some sites in the Northern Hemisphere, UV-B irradiance may continue to increase because of continuing reductions in aerosol extinctions since the 1990s. Interactions between ozone depletion and climate change are complex and can be mediated through changes in chemistry, radiation, and atmospheric circulation patterns. The changes can be in both directions: ozone changes can affect climate, and climate change can affect ozone. The observational evidence suggests that stratospheric ozone (and therefore UV-B) has responded relatively quickly to changes in ozone-depleting substances, implying that climate interactions have not delayed this process. Model calculations predict that at mid-latitudes a return of ozone to pre-1980 levels is expected by the mid 21st century. However, it may take a decade or two longer in polar regions. Climate change can also affect UV radiation through changes in cloudiness and albedo, without involving ozone and since temperature changes over the 21st century are likely to be about 5 times greater than in the past century. This is likely to have significant effects on future cloud, aerosol and surface reflectivity. Consequently, unless strong mitigation measures are undertaken with respect to climate change, profound effects on the biosphere and on the solar UV radiation received at the Earth's surface can be anticipated. The future remains uncertain. Ozone is expected to increase slowly over the decades ahead, but it is not known whether ozone will return to higher levels, or lower levels, than those present prior to the onset of ozone depletion in the 1970s. There is even greater uncertainty about future UV radiation, since it will be additionally influenced by changes in aerosols and clouds.
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Affiliation(s)
- R L McKenzie
- National Institute of Water and Atmospheric Research, NIWA Lauder, PB 50061, Omakau, Central Otago, New Zealand
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Fast JD, Gustafson WI, Easter RC, Zaveri RA, Barnard JC, Chapman EG, Grell GA, Peckham SE. Evolution of ozone, particulates, and aerosol direct radiative forcing in the vicinity of Houston using a fully coupled meteorology-chemistry-aerosol model. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006721] [Citation(s) in RCA: 708] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Using a Parameterization of a Radiative Transfer Model to Build High-Resolution Maps of Typical Clear-Sky UV Index in Catalonia, Spain. ACTA ACUST UNITED AC 2005. [DOI: 10.1175/jam2237.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
To perform a climatic analysis of the annual UV index (UVI) variations in Catalonia, Spain (northeast of the Iberian Peninsula), a new simple parameterization scheme is presented based on a multilayer radiative transfer model. The parameterization performs fast UVI calculations for a wide range of cloudless and snow-free situations and can be applied anywhere. The following parameters are considered: solar zenith angle, total ozone column, altitude, aerosol optical depth, and single-scattering albedo. A sensitivity analysis is presented to justify this choice with special attention to aerosol information. Comparisons with the base model show good agreement, most of all for the most common cases, giving an absolute error within ±0.2 in the UVI for a wide range of cases considered. Two tests are done to show the performance of the parameterization against UVI measurements. One uses data from a high-quality spectroradiometer from Lauder, New Zealand [45.04°S, 169.684°E, 370 m above mean sea level (MSL)], where there is a low presence of aerosols. The other uses data from a Robertson–Berger-type meter from Girona, Spain (41.97°N, 2.82°E, 100 m MSL), where there is more aerosol load and where it has been possible to study the effect of aerosol information on the model versus measurement comparison. The parameterization is applied to a climatic analysis of the annual UVI variation in Catalonia, showing the contributions of solar zenith angle, ozone, and aerosols. High-resolution seasonal maps of typical UV index values in Catalonia are presented.
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Kazadzis S, Bais A, Kouremeti N, Gerasopoulos E, Garane K, Blumthaler M, Schallhart B, Cede A. Direct spectral measurements with a Brewer spectroradiometer: absolute calibration and aerosol optical depth retrieval. APPLIED OPTICS 2005; 44:1681-1690. [PMID: 15813271 DOI: 10.1364/ao.44.001681] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present three different methods for the absolute calibration of direct spectral irradiances measured with a Brewer spectroradiometer, which are shown to agree to within +/- 2%. Direct irradiance spectra derived by Brewer and Bentham spectroradiometers agree to within 4 +/- 3%. Good agreement was also found by a comparison of the aerosol optical depth and Angstrom exponent retrieved by the two instruments and a multifilter rotational shadowband radiometer. The spectral aerosol optical depth (300-365 nm) derived from six years of direct irradiance measurements at Thessaloniki shows a distinct seasonal variation, averaging to approximately 0.3 at 340 nm in winter and approximately 0.7 in summer.
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Affiliation(s)
- Stelios Kazadzis
- Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, P.O. Box 149, Thessaloniki 54124, Greece.
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12
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Arola A, Kazadzis S, Krotkov N, Bais A, Gröbner J, Herman JR. Assessment of TOMS UV bias due to absorbing aerosols. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jd005913] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Kassianov EI. Retrieval of aerosol microphysical properties using surface MultiFilter Rotating Shadowband Radiometer (MFRSR) data: Modeling and observations. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jd005337] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Goering CD. Simultaneous retrievals of column ozone and aerosol optical properties from direct and diffuse solar irradiance measurements. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jd005330] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cheymol A, De Backer H. Retrieval of the aerosol optical depth in the UV-B at Uccle from Brewer ozone measurements over a long time period 1984-2002. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003758] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anne Cheymol
- Royal Meteorological Institute of Belgium; Uccle Belgium
| | - Hugo De Backer
- Royal Meteorological Institute of Belgium; Uccle Belgium
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Wetzel MA. Physical, chemical, and ultraviolet radiative characteristics of aerosol in central Alaska. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jd003208] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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