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John N. Porter, Antony Clarke, Jeffrey S. Reid, Elizabeth A. Reid, Glen Shaw, Hal Maring, and David Kress

anthropogenic sources in eastern Europe and Russia. More recently, several investigators have employed hand-operated sun photometers to collect aerosol optical depths from aircraft. Beginning in approximately 1995, Antony Clarke and John Porter collected manual aircraft sun photometer measurements near Hawaii to study marine aerosol conditions. These aircraft measurements continued intermittently for the next 10 yr during which general procedures were developed ( Porter et al. 2000 ). In a separate and

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Jun Li, Christopher C. Schmidt, James P. Nelson III, Timothy J. Schmit, and W. Paul Menzel

1. Introduction There has been much interest in atmospheric ozone in recent decades, due primarily to its role in complex mid-atmospheric photochemistry and the critical ecological effects associated with ozone depletion induced by anthropogenic impacts and natural processes. The evolution of the “ozone hole” and its interannual variability can be detected and even predicted by means of satellite observations. The main satellite instruments used for monitoring ozone are the Total Ozone Mapping

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C. M. Roithmayr, C. Lukashin, P. W. Speth, D. F. Young, B. A. Wielicki, K. J. Thome, and G. Kopp

1. Introduction It is essential that we understand the nature of the changes taking place in Earth’s climate, correctly attribute the changes to natural variability or anthropogenic effects, make reliable long-term forecasts for the magnitude of those changes, and act accordingly. We must have high confidence in our predictions of climate because our response may entail enormous societal and economic costs. Earth’s thermal infrared and reflected solar radiation are among the quantities that

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Patricia Castellanos and Arlindo da Silva

. The G5NR simulation was driven by prescribed sea surface temperature and sea ice, daily sources of volcanic and biomass burning aerosols and trace gases, high-resolution anthropogenic aerosol and trace gas emissions, sinks of aerosols and trace gases, and biogenic sources and sinks of CO 2 . Aerosol processes in GEOS are derived from the Goddard Chemistry, Aerosol, Radiation, and Transport model (GOCART; Chin et al. 2002 ), with tracer transport running online coupled to the GEOS radiation code

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Ganesh K. Subramanian and Andreas Muschinski

short note, Benioff and Gutenberg (1939) report a dominating period of 4 s for natural infrasound, as opposed to anthropogenic infrasound from ships, aircraft, gunfire, mine blasts, etc. Similar to their seismic cousins known as “microseisms” (e.g., Tabulevich 1992 ), microbaroms are acoustic pressure waves that are generated by standing or quasi-standing ocean surface waves ( Daniels 1953 ; Posmentier 1967 ; Arendt and Fritts 2000 ; Waxler and Gilbert 2006 ). Gossard and Hooke (1975 , 295ff

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Derek J. Straub and Jeffrey L. Collett Jr.

include cloud types and environments not accessible from the surface. Cloud water samples acquired from aircraft platforms have been used for the investigation of cloud nucleation mechanisms, aerosol and trace gas scavenging, sulfate production, cloud water acidification, the influence of anthropogenic pollution, the distribution of trace species in the atmosphere, and the general characterization of cloud water composition at geographical locations around the world. Historically, the most common

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Andreas Andersson, Anna Rutgersson, and Erik Sahlée

emitted anthropogenic carbon dioxide, causing ocean acidification. Variability of oxygen gives additional information about the carbon cycle, not contained in the variability of CO 2, due to the different reactivity and equilibrium time scale of oxygen and CO 2 ( Körtzinger et al. 2008 ). During the last decade, there has been increasing interest in oxygen minimum zones (OMZ). OMZ are zones in the water column typically 200–1000 m in depth where oxygen concentration is at its lowest and hypoxia

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Jean-Charles Dupont, Martial Haeffelin, Jordi Badosa, Gaelle Clain, Christophe Raux, and Damien Vignelles

humidity measurements from the ground to the top of the troposphere and lower stratosphere are necessary to prevent spurious drying or moistening of the atmosphere simulated in numerical weather prediction models ( Seidel et al. 2009 ). Such measurements are also necessary to better understand the role of water vapor in climate feedback, to study the life cycle of anthropogenic clouds such as contrails, and to quantify the state of deliquescence of atmospheric aerosols, just to name a few among many

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J. H. Middleton, C. G. Cooke, E. T. Kearney, P. J. Mumford, M. A. Mole, G. J. Nippard, C. Rizos, K. D. Splinter, and I. L. Turner

between estimates of the offset of lidar and ATV data when one considers the general undulating nature of a beach surface. The 6 C 2 data The beneficial effects of weaving become apparent, and the significantly reduced standard deviations are evident in all the estimates compared with the 6 C 1 data. Weaving with two runs is clearly beneficial, as the standard deviations are now comparable to those with the 5 C 1 data, which excludes run 7. The 6 C 3 data Standard deviations of the differences of mean

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Janek Uin, Allison C. Aiken, Manvendra K. Dubey, Chongai Kuang, Mikhail Pekour, Cynthia Salwen, Arthur J. Sedlacek, Gunnar Senum, Scott Smith, Jian Wang, Thomas B. Watson, and Stephen R. Springston

1. Introduction a. Inception of ARM Aerosols are ubiquitous in Earth’s atmosphere and are directly emitted from natural and anthropogenic sources as well as formed in the atmosphere. They alter Earth’s radiative budget directly by absorbing and scattering light and indirectly by altering cloud properties and processes such as formation, lifetime, and albedo. To achieve radiative closure at Earth’s surface, knowledge of local aerosol loading and optical properties are required. Because of their

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