Search Results

You are looking at 41 - 50 of 7,608 items for :

  • Optical properties x
  • All content x
Clear All
J. G. DeVore

analogous situation exists with the shape of solar extinction spectra—for example, as seen through aerosol layers. In this case the wavelength dependence of the aerosol optical depth depends sensitively on the size distribution of particles comparable to and smaller than the wavelength of sunlight. Many different algorithms have been developed (see for example King et al. 1978 ) exploiting this dependence since the pioneering work of Ångström (1929) . Solar extinction spectra are measured routinely by

Full access
R. Uijlenhoet, J.-M. Cohard, and M. Gosset

. A. R. , Meijninger W. M. L. , and Schipper F. , 2002 : Experiences from one-year continuous operation of a large aperture scintillometer over a heterogeneous land surface . Bound.-Layer Meteor. , 105 , 85 – 97 . Bradley, S. G. , Stow C. D. , and Lynch-Blosse C. A. , 2000 : Measurements of rainfall properties using long optical path imaging . J. Atmos. Oceanic Technol. , 17 , 761 – 772 . Cain, J. D. , Rosier P. T. W. , Meijninger W. , and de Bruin H. A. R. , 2001

Full access
U. C. Dumka, K. Krishna Moorthy, S. K. Satheesh, Ram Sagar, and P. Pant

, thereby leading to increased AODs in the AN period. Aerosols over the Indian subcontinent may have implications for cloud microphysical properties and the radiation budget. 5. Conclusions Multiyear measurements of spectral aerosol optical depths (AODs) made at Manora Peak in the central Himalayas have revealed the following. The AODs at 0.5 μ m were very low (≤0.1) in winter and increased rather steeply to reach high values (∼0.5) in summer. The monthly mean AODs vary significantly (by more than a

Full access
T. Cherubini, S. Businger, R. Lyman, and M. Chun

1. Introduction Atmospheric turbulence is a key challenge in ground-based astronomy because it dramatically impacts the angular resolution of a telescope. Small-scale temperature and moisture fluctuations in the atmosphere result in fluctuations of the refractive index. The wave front of radiation traveling through the atmosphere changes as it encounters inhomogeneities in the refractive index, degrading optical image quality. The intensity of the turbulent fluctuations of the atmospheric

Full access
Carl G. Schmitt, Martin Schnaiter, Andrew J. Heymsfield, Ping Yang, Edwin Hirst, and Aaron Bansemer

.1 . Field , P. R. , R. Wood , P. R. A. Brown , P. H. Kaye , E. Hirst , and R. Greeaway , 2003 : Ice particle interarrival times measured with a fast FSSP . J. Atmos. Oceanic Technol. , 20 , 249 – 261 , doi: 10.1175/1520-0426(2003)020<0249:IPITMW>2.0.CO;2 . Gayet , J.-F. , G. Mioche , V. Shcherbakov , C. Gourbeyre , R. Busen , and A. Minikin , 2011 : Optical properties of pristine ice crystals in mid-latitude cirrus clouds: A case study during CIRCLE-2 experiment

Full access
Guy Potvin, Denis Dion, Jacques Claverie, Paul A. Frederickson, Kenneth L. Davidson, and J. Luc Forand

1. Introduction Atmospheric turbulence can significantly affect the performance of electro-optical imaging systems to detect and identify objects, being responsible for scintillation, blurring, and image wandering. The theory, in the scientific literature, relates the turbulence effects to the optical refractive index structure parameter C 2 n , which characterizes the rapid fluctuation of the index of refraction ( Beland 1993 ). For predicting turbulence effects on an imaging system, it would

Full access
Ming-Dah Chou, Pui-King Chan, and Menghua Wang

surface. Over oceans, the surface reflectivity is small and aerosol optical properties can be estimated much more reliably than that over land. The Total Ozone Mapping Spectrometer (TOMS) retrieves the aerosol distribution over both land and oceans by means of aerosol index, which is related to the aerosol optical thickness and the single scattering albedo ( Herman et al. 1997 ). Distributions of aerosols over global oceans have been derived from various satellite radiance measurements. For example

Full access
Chao Xu, Yaoming Ma, Kun Yang, and Chao You

, 2012 : CALIPSO observations of transatlantic dust: Vertical stratification and effect of clouds . Atmos. Chem. Phys. , 12 , 11 339 – 11 354 , https://doi.org/10.5194/acp-12-11339-2012 . 10.5194/acp-12-11339-2012 Yao , T. D. , and Coauthors , 2012 : Third Pole Environment (TPE) . Environ. Dev. , 3 , 52 – 64 , https://doi.org/10.1016/j.envdev.2012.04.002 . 10.1016/j.envdev.2012.04.002 Yi , B. Q. , P. Yang , and B. A. Baum , 2014 : Impact of pollution on the optical properties of trans-Pacific East

Full access
Philippe Dubuisson, Vincent Giraud, Jacques Pelon, Bertrand Cadet, and Ping Yang

1. Introduction Ice clouds play an important role in the earth’s radiation budget and climate ( Liou 1986 ). Accurate information of their optical properties is critical to assessing the climate effects and feedback associated with these clouds ( Stephens et al. 1990 ). Reflected solar radiation and emitted longwave radiation under cirrus cloudy conditions depend strongly upon the complex microphysical properties of these clouds ( Mitchell et al. 1996 ; Fu et al. 1998 , 1999 ; Chepfer et al

Full access
C. M. R. Platt and K. Bartusek

MA-1974 C.M.R. PLATT AND K. BARTUSEK 1079Structure and Optical Properties of Some Middle-Level Clouds C. M. R. ~PLATTDivision of A tmospheric Physics, CSIRO, A spendale, Victoria, A ustrallaK. BaRTUSEK~Dept. of Physics, University of Adelaide, Adelaide, South Australia(Manuscript received 11 June 1973, in revised form 28 December 1973)ABSTRACT Simultaneous infrared (10-12/~m

Full access