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Kenneth E. Kunkel, Michael A. Palecki, Kenneth G. Hubbard, David A. Robinson, Kelly T. Redmond, and David R. Easterling

effects. Snow is an important component of annual runoff, recharge, and water supplies, and greatly affects water management in the northern and western United States. Rapid melt of snowpack is a major cause of floods in the northern United States. Recent studies have examined historical variability in snow cover ( Hughes and Robinson 1996 ; Frei et al. 1999 ). However, studies of trends in other aspects of snow climatology, such as snowfall and snow depth, have generally examined records from the

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K. S. Hintz, H. Vedel, E. Kaas, and N. W. Nielsen

identification number. Additional metadata were collected from other sources to assess the impact of using the roughness length derived from the HWMs and to examine the effects of the stability correction: We looked at the characteristics of the surface in the form of roughness lengths from two different sources, used for comparison with the roughness length determined via the HWMs. In addition, the surface was characterized subjectively by the authors. We looked at the lower tropospheric atmospheric

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Pierre Cauchy, Karen J. Heywood, Nathan D. Merchant, Bastien Y. Queste, and Pierre Testor

underwater sound sources (e.g., spectrum shape, time variability) allow wind-generated noise to be isolated and quantified ( Fig. 1 ). Fig . 1. Spectra of the typical contributions to underwater ambient noise in the open ocean, from anthropogenic (dashed), biotic (dotted), and abiotic (continuous) sources [adapted from Wenz (1962 )]. In the absence of heavy rain events or nearby biotic activity, wind-generated noise is predominant in the 500 Hz–20 kHz frequency range. Underwater noise generated by

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Patrick Y. Chuang, Athanasios Nenes, James N. Smith, Richard C. Flagan, and John H. Seinfeld

1. Introduction Cloud condensation nuclei (CCN), those particles that nucleate cloud droplet formation, influence the droplet number and size distribution in a cloud, which in turn determine the cloud albedo, lifetime, and precipitation rate, with important climate effects ( IPCC 1996 ; Twomey 1977 ). Knowledge of the nature of CCN is essential to understanding possible anthropogenically induced climate change. Ideally, a measurement of cloud condensation nuclei would reveal the distribution

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Michael E. Feinholz, Stephanie J. Flora, Mark A. Yarbrough, Keith R. Lykke, Steven W. Brown, B. Carol Johnson, and Dennis K. Clark

earth’s carbon balance and the relationship between the ocean’s productivity and the earth’s climate. Multisensor, multiyear measurements are required to develop an understanding of the state of the world’s oceans and their response to environmental changes. Of particular interest are measurements of oceanic ecosystem changes attributable to anthropogenic origins. Meaningful synthesis of measurements from multiple sensors over decadal time scales into a coherent picture of the evolution of the earth

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Steven D. Miller, Cynthia L. Combs, Stanley Q. Kidder, and Thomas F. Lee

unique information for numerous qualitative and quantitative nighttime applications. Studies on population density ( Sutton et al. 2001 ), economic activity (e.g., Ebener et al. 2005 ), and atmospheric emissions (e.g., Toenges-Schuller et al. 2006 ) use correlations between these parameters and the distribution/intensity of anthropogenic light emissions. Environmental studies related to aerosol properties ( Zhang et al. 2008 ), cloud and snow/ice cover ( Foster and Hall 1991 ; Miller et al. 2005b

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Kevin S. Repasky, John A. Reagan, Amin R. Nehrir, David S. Hoffman, Michael J. Thomas, John L. Carlsten, Joseph A. Shaw, and Glenn E. Shaw

aerosol optical depth and lidar ratio retrieved using the solar radiometer. Furthermore, the scattering component of the aerosol extinction calculated using the single-scatter albedo retrieved with the solar radiometer and the total aerosol extinction retrieved using the two-color lidar is compared with the scattering component of the aerosol extinction measured using the ground-based nephelometer. The ability to measure aerosol optical properties is important for understanding the effects of aerosols

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Fabien Gibert, Pierre H. Flamant, Juan Cuesta, and Didier Bruneau

observe 1) large regional- and synoptic-scale sources, sinks, and gradients in the ABL ( Wang et al. 2007 ); 2) changes in tropospheric CO 2 associated with the passage of strong frontal boundaries (magnitude of a few to 40 ppm; Hurwitz et al. 2004 ); and 3) variations of the mean CO 2 mixing ratio in the ABL due to anthropogenic emissions ( Idso et al. 2002 ; Braud et al. 2004 ). However, this will only marginally constrain the ABL-mean diurnal cycle in CO 2 associated with the biological cycle

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Grant Matthews

climate on the earth. The measurement accuracy and calibration stability required to detect model-predicted effects of cloud–climate feedbacks on the ERB has recently been estimated by Ohring et al. (2005) . The standards called for are an absolute accuracy of 1 W m −2 , a calibration stability of ±0.3% decade −1 for SW flux, and ±0.5% decade −1 for LW flux. The Clouds and the Earth’s Radiant Energy System (CERES; Wielicki et al. 1996 ) is currently the only satellite program monitoring global ERB

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David J. Bodine, Robert D. Palmer, Takashi Maruyama, Caleb J. Fulton, Ye Zhu, and Boon Leng Cheong

techniques, conductive and dielectric losses are carefully taken into account, but the weaker edge diffraction effects are not. The value of for wood boards computed from T-matrix calculations and the POA model are shown in Fig. 3 for a concentration of 1 m −3 . POA is shown for both dry (asterisks) and wet wood boards (circles). For the dry wood board calculations, mean averaged over all diameters is greater for the POA model compared to T-matrix calculations by 0.8–7.4 dB. Atlas (1953) found

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