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G. S. Kent, F. Köpp, and Ch Werner

)ABSTRACT Remote sensing of the lower atmosphere by lidar yields profiles of the backscattering cross sectionalong the optical path. These may be simply converted to give a qualitative picture of the distributionof atmospheric aerosol, but quantitative values can only be obtained if further information is availableon aerosol properties such as refractive index and size distribution. In the experiments described below,use was made of a solar radiometer to give information on the second of these. This

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Yong-Sang Choi, Chang-Hoi Ho, Jinwon Kim, Dao-Yi Gong, and Rokjin J. Park

cooling of lower-level stratiform clouds or the lower part of convective clouds, or both, as shown in previous studies ( Toon 2003 ; Khain et al. 2005 ; Lau et al. 2005 ). We examine the occurrence of additional ice nucleation under high aerosol concentration episodes using satellite measurements of cloud properties including the thermodynamic phase of cloud particles, cloud-top pressure, cloud optical depth, and effective particle radius. The satellite data are the 1° × 1° gridded Moderate

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William L. Smith Sr., Elisabeth Weisz, Stanislav V. Kireev, Daniel K. Zhou, Zhenglong Li, and Eva E. Borbas

assumed, and the classical Lorenz–Mie theory is used to compute their single scattering properties. In the model input, the cloud optical thickness is specified in terms of its visible optical thickness at 0.55 μ m. The IR cloud optical thickness for each spectral channel can be derived through the relationship τ = τ vis ( Q e /2), where τ is the cloud optical thickness and Q e is the bulk mean extinction efficiency. Given the visible cloud optical thickness and the cloud-particle diameter

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Catherine M. Naud and Brian H. Kahn

cloud cover above 440 hPa. They found similar results whether the cyclones were found over the Northern or Southern Hemisphere oceans but did not explore cyclones over land. Here we would like to complement the work of FW07 and further explore 1) the microphysical properties of ice clouds that form in extratropical cyclones and 2) the potential differences between land and ocean cyclones. Cloud-top properties are important because they impact the radiation fluxes at the top of the atmosphere

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Itamar M. Lensky and Daniel Rosenfeld

estimate cloud optical thickness in that wave band (e.g., Arking and Childs 1985), which depends mainly on the vertically integrated amount of cloud condensates. Channel 3 (3.70 μ m) is very sensitive to the cloud drop size distribution, to the thermodynamic phase, and to the particles shape (Arking and Childs 1985). Channel 4 (10.8 μ m) provides the cloud-top blackbody brightness temperature, which approximates the cloud-top temperature, assuming that the atmosphere above the cloud is relatively dry

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J.-P. Vernier, T. D. Fairlie, J. J. Murray, A. Tupper, C. Trepte, D. Winker, J. Pelon, A. Garnier, J. Jumelet, M. Pavolonis, A. H. Omar, and K. A. Powell

(or sulfate) clouds location in the UTLS, at levels between 20 000 and 40 000 ft (6–13 km), where most commercial and military air transport traffic at midlatitudes are concentrated. The trajectory mapping system we have illustrated is primarily based upon the detection of volcanic clouds via the analysis of their optical properties obtained from the CALIPSO lidar. The major result of this study is to show for the first time how observations from the CALIPSO lidar can be combined with a

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Min Deng, Gerald G. Mace, Zhien Wang, and R. Paul Lawson

.53, respectively. The 2D-S estimates of cloud properties reported here are based on preliminary analysis and archiving by SPEC. The archived data are thought to be reliable; however, as with most datasets processed soon after a field campaign, refinements and improvements in data are an evolutionary process. In cases with relatively high concentrations of millimeter-size particles, the 2D precipitation (2D-P) particle imaging probe (an external optical system that images particles in the size range 200–6400 μ

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David P. Duda, Graeme L. Stephens, and S. K. Cox

and shortwave radiation measurements throughthe marne boundary layer were obtained using an instrument package on the NASA tethered balloon duringthe FIRE Marine Stratocumulus Experiment. The radiation observations were analyzed to determine heatingrates inside the stratocumulus clouds during several tethered balloon flights. The radiation fields in the cloudlayer were also simulated by a two-stream radiative transfer model, which used cloud optical properties derivedfrom microphysical

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David Atlas, Zhien Wang, and David P. Duda

humidity. The optical thickness also increases sharply with RH i ( Jensen et al. 1998 ). c. Microphysical and optical properties We now move on to the lidar observations in Fig. 6 . As noted earlier, the fallstreak generators are just above 10-km level with ALSR >50 most of the time. In the fallstreaks ALSR ≈20. Note that the initial generator and fallstreak A occurs between 1618 and 1636 UTC, about 40–60 min after the cloud photographs. Using the 6.2 m s −1 component of the wind speed of the

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Ralf Bennartz and Grant W. Petty

hydrometeor profiles from the radar data and is described in section 2 . Based on Mie calculations for different size factors, precipitation rates, and particle densities, we investigate the relative effect of these parameters on microwave optical properties ( section 3 ). In section 4 we apply the new method to three different precipitation events and evaluate the relative effect of ice particle size and density. The precipitation events were observed during the Baltic Sea Experiment–Pilot Study for

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