Airborne Sun photometer measurements of aerosol optical depth and columnar water vapor during the Puerto Rico Dust Experiment and comparison with land, aircraft, and satellite measurements

2003 ◽  
Vol 108 (D19) ◽  
Author(s):  
John M. Livingston
Keyword(s):  
Puerto Rico ◽  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Satellite Measurements ◽  
Columnar Water Vapor ◽  
Sun Photometer

scholarly journals Shipboard sunphotometer measurements of aerosol optical depth spectra and columnar water vapor during ACE-2, and comparison with selected land, ship, aircraft, and satellite measurements

Tellus B ◽  
2000 ◽  
Vol 52 (2) ◽  
pp. 594-619
Author(s):  
John M. Livingstone ◽  
Vladimir N. Kapustin ◽  
Beat Schmid ◽  
Philip B. Russel ◽  
Patricia K. Quinn ◽  
...  
Keyword(s):  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Satellite Measurements ◽  
Columnar Water Vapor

scholarly journals Retrieval of atmospheric optical parameters from ground-based sun-photometer measurements for Zanjan, Iran

2011 ◽  
Vol 4 (5) ◽  
pp. 857-863 ◽  
Author(s):  
A. Bayat ◽  
A. Masoumi ◽  
H. R. Khalesifard
Keyword(s):  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Dust Particles ◽  
The Sun ◽  
Angstrom Exponent ◽  
Columnar Water Vapor ◽  
Ångström Exponent ◽  
Sun Photometer ◽  
Ångstrom Exponent

Abstract. We are reporting the results of ground-based spectroradiometric measurements on aerosols and water vapor in the atmosphere of Zanjan for the period of October 2006 to September 2008 using a CIMEL CE318-2 sun-photometer. Zanjan is a city in Northwest Iran, located at 36.70° N, 48.51° E, and at an altitude of 1800 m a.m.s.l. (above mean sea level). The spectral aerosol optical depth, Ångström exponent, and columnar water vapor have been calculated using the data recorded by the sun-photometer through the direct measurements on the sun radiance (sun-mode). The average values of aerosol optical depth at 440 nm, columnar water vapor, and the Ångström exponent, α, during the mentioned period are measured as, 0.28 ± 0.14, 0.57 ± 0.37 cm and 0.73 ± 0.30, respectively. The maximum (minimum) value of the aerosol optical depth was recorded in May 2007 (November 2007), and that of columnar water vapor, in July 2007 (January 2008). Using the least-squares method, the Ångström exponent was calculated in the spectral interval 440–870 nm along with α1 and α2, the coefficients of a second order polynomial fit to the plotted logarithm of aerosol optical depth versus the logarithm of wavelength. The coefficient α2 shows that most of the aerosols in the Zanjan area have dimensions larger than 1 micron. The calculated values for α2 − α1 indicate that 80 % of the aerosols are in the coarse-mode (>1 μm) and 20 % of them are in the fine-mode (<1 μm). Comparison of α2 − α1 for the atmosphere over Zanjan with other regions indicates dust particles are the most dominant aerosols in the region.

scholarly journals Retrieval of atmospheric optical parameters from ground-based sun-photometer measurements for Zanjan, Iran

2010 ◽  
Vol 3 (3) ◽  
pp. 2633-2649 ◽  
Author(s):  
A. Bayat ◽  
A. Masoumi ◽  
H. R. Khalesifard
Keyword(s):  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Optical Parameters ◽  
Anthropogenic Aerosols ◽  
Angstrom Exponent ◽  
Columnar Water Vapor ◽  
Ångström Exponent ◽  
Sun Photometer ◽  
Ångstrom Exponent

Abstract. We are reporting the results of ground-based spectroradiometric measurements on aerosols and water vapor in the atmosphere of Zanjan for the period of October 2006 to September 2008 using a Cimel CE318-2 sun-photometer. Zanjan is a city in Northwest Iran, located at 36.70° N, 48.51° E, and at an altitude of 1800 above m.s.l. The spectral aerosol optical depth, Ångström exponent, and columnar water vapor have been calculated using the data recorded by the sunphotometer through direct-beam irradiance measurements of sunlight (sun mode). The average values of aerosol optical depth at 440 nm, columnar water vapor, and the Ångström exponent, α, during the mentioned period are measured as, 0.27±0.16, 0.53±0.37 cm and 0.75±0.46, respectively. The maximum (minimum) value of the aerosol optical depth was recorded in May 2007 (January 2007), and that of columnar water vapor, in July 2007 (January 2008). Using the least-squares method, the Ångström exponent was calculated in the spectral interval 440–870 nm along with the coefficients of a second order polynomial fit (α1 and α2) to the log-log plot of aerosol optical depth versus the wavelength. The coefficient α2 shows that most of the aerosols in the Zanjan area have dimensions larger than 1 μm. The values calculated for α2−α1 indicate that 70% of the aerosols are in the coarse-mode (>1 μm) and 30% of them are in the fine-mode (<1 μm). Comparison of α2−α1 for the atmosphere over Zanjan with other regions indicates dust and anthropogenic aerosols are the most dominant aerosols in the region.

scholarly journals Evaluation of the new ESR network software for the retrieval of direct sun products from CIMEL CE318 and PREDE POM01 sun-sky radiometers

2012 ◽  
Vol 12 (23) ◽  
pp. 11619-11630 ◽  
Author(s):  
V. Estellés ◽  
M. Campanelli ◽  
T. J. Smyth ◽  
M. P. Utrillas ◽  
J. A. Martínez-Lozano
Keyword(s):  
Water Vapor ◽  
Open Source ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Single Scattering ◽  
Research Network ◽  
Columnar Water Vapor ◽  
Standard Calibration ◽  
Sun Photometer ◽  
Network Software

Abstract. The European Skynet Radiometers network (EuroSkyRad or ESR) has been recently established as a research network of European PREDE sun-sky radiometers. Moreover, ESR is federated with SKYNET, an international network of PREDE sun-sky radiometers mostly present in East Asia. In contrast to SKYNET, the European network also integrates users of the CIMEL CE318 sky–sun photometer. Keeping instrumental duality in mind, a set of open source algorithms has been developed consisting of two modules for (1) the retrieval of direct sun products (aerosol optical depth, wavelength exponent and water vapor) from the sun extinction measurements; and (2) the inversion of the sky radiance to derive other aerosol optical properties such as size distribution, single scattering albedo or refractive index. In this study we evaluate the ESR direct sun products in comparison with the AERosol RObotic NETwork (AERONET) products. Specifically, we have applied the ESR algorithm to a CIMEL CE318 and PREDE POM simultaneously for a 4-yr database measured at the Burjassot site (Valencia, Spain), and compared the resultant products with the AERONET direct sun measurements obtained with the same CIMEL CE318 sky–sun photometer. The comparison shows that aerosol optical depth differences are mostly within the nominal uncertainty of 0.003 for a standard calibration instrument, and fall within the nominal AERONET uncertainty of 0.01–0.02 for a field instrument in the spectral range 340 to 1020 nm. In the cases of the Ångström exponent and the columnar water vapor, the differences are lower than 0.02 and 0.15 cm, respectively. Therefore, we present an open source code program that can be used with both CIMEL and PREDE sky radiometers and whose results are equivalent to AERONET and SKYNET retrievals.

Shipboard sunphotometer measurements of aerosol optical depth spectra and columnar water vapor during ACE-2, and comparison with selected land, ship, aircraft, and satellite measurements

Tellus B ◽  
2000 ◽  
Vol 52 (2) ◽  
pp. 594-619 ◽  
Author(s):  
John M. Livingston ◽  
Vladimir N. Kapustin ◽  
Beat Schmid ◽  
Philip B. Russell ◽  
Patricia K. Quinn ◽  
...  
Keyword(s):  
Water Vapor ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Satellite Measurements ◽  
Columnar Water Vapor

scholarly journals Retrieval of aerosol single-scattering albedo and polarized phase function from polarized sun-photometer measurements for Zanjan's atmosphere

2013 ◽  
Vol 6 (10) ◽  
pp. 2659-2669 ◽  
Author(s):  
A. Bayat ◽  
H. R. Khalesifard ◽  
A. Masoumi
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Atmospheric Aerosols ◽  
Phase Function ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Angstrom Exponent ◽  
Ångström Exponent ◽  
Sun Photometer ◽  
Ångstrom Exponent

Abstract. The polarized phase function of atmospheric aerosols has been investigated for the atmosphere of Zanjan, a city in northwest Iran. To do this, aerosol optical depth, Ångström exponent, single-scattering albedo, and polarized phase function have been retrieved from the measurements of a Cimel CE 318-2 polarized sun-photometer from February 2010 to December 2012. The results show that the maximum value of aerosol polarized phase function as well as the polarized phase function retrieved for a specific scattering angle (i.e., 60°) are strongly correlated (R = 0.95 and 0.95, respectively) with the Ångström exponent. The latter has a meaningful variation with respect to the changes in the complex refractive index of the atmospheric aerosols. Furthermore the polarized phase function shows a moderate negative correlation with respect to the atmospheric aerosol optical depth and single-scattering albedo (R = −0.76 and −0.33, respectively). Therefore the polarized phase function can be regarded as a key parameter to characterize the atmospheric particles of the region – a populated city in the semi-arid area and surrounded by some dust sources of the Earth's dust belt.

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