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Zhen Zeng, Sergey Sokolovskiy, William S. Schreiner, and Doug Hunt

computationally efficient. On the other hand, PM is the most accurate, because it uses least assumptions and approximations. Typically, both GO and WO are combined in processing a RO profile; GO is applied for upper levels (e.g., stratosphere), while WO is more often applied for lower levels (e.g., troposphere). An important feature associated with GO and WO approaches is the vertical resolution of RO retrievals. The vertical resolution of GO retrievals is limited by diffraction effects in the atmosphere and

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Michael Carter, J. Marshall Shepherd, Steve Burian, and Indu Jeyachandran

). Souch and Grimmond (2006) summarize much of the previous research on the characteristics of the urban heat island, stating that it reaches its diurnal peak during the nighttime hours, that it can be limited by increased wind speed and cloud cover, that its intensity varies by season with the minimum signal occurring in summer, and that it is strongly related to surface–building geometry, land use, vegetation, and patterns of anthropogenic heat release. The thermal and dynamic effects of the UHI

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G. Abessolo Ondoa, R. Almar, B. Castelle, L. Testut, F. Léger, Z. Sohou, F. Bonou, E. W. J. Bergsma, B. Meyssignac, and M. Larson

1. Introduction The nearshore coastal zone is the interface between land and the continental shelf ( Komar 1998 ; Elko et al. 2014 ). Coastal areas are often densely populated and evolve under an increasing threat from sea level rise, long-term erosion, extreme storms, and anthropogenic influences ( Vousdoukas et al. 2018 ; Anderson et al. 2018 ). Remote sensing and in situ instrumentation enabled improved understanding of nearshore hydro- and morphodynamic processes. However, complex and

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Hiroshi Suto and Gen Inoue

1. Introduction Climate change caused by anthropogenic emissions of greenhouse gases such as carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) is one of the most serious global environmental problems of the twenty-first century ( Forster et al. 2007 ). To predict future climate change, the present status of atmospheric greenhouse gases must be monitored in numerous areas worldwide to understand the transport, distribution, and strength of emission sources and sinks in the

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Cong Long Zhao, Peter S. Bakwin, and Pieter P. Tans

anthropogenic greenhouse gas, is being absorbed or lost by ecosystems. This strategy aims to determine CO 2 mixing ratios representative of continental areas, and thereby allow terrestrial net fluxes to be better quantified using global models of atmospheric transport. To minimize the effects of local sources and sinks on mixing ratio measurements, the methods were designed to measure CO 2 and other trace gases continuously on existing very tall towers. System design for the tower project began in May

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Jose Luis Palau and Francisco Rovira

. Background: Tropospheric ozone cycles in the Mediterranean basin Tropospheric ozone variability is strongly dependent on meteorological fluctuations and anthropogenic influences. This is because ozone formation is related to temperature, solar radiation, NO x emissions, and volatile organic compound (VOC) concentrations ( Sebald et al. 2000 ). Thus, since meteorology and anthropogenic emissions have cyclical patterns, it is reasonable to expect that the variability in the ambient ozone concentration

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Gottfried Hänel and Karin Kastner

. The model equations (13)–(15) are exact regarding the direct solar radiation. In case of sky radiation and reflected radiation, any brightness differences among the 48 solid angle subareas are allowed and would be treated exactly if within each of these areas the radiance were isotropic. Consequently, the model error stems only from nonisotropy effects on the level of the individual subareas. Thus, our subdivision of the total solid angle 4 π sr into 48 parts should lead to a good approximation

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Y. Té, E. Dieudonné, P. Jeseck, F. Hase, J. Hadji-Lazaro, C. Clerbaux, F. Ravetta, S. Payan, I. Pépin, D. Hurtmans, J. Pelon, and C. Camy-Peyret

paper, we present the results on nitrous oxide (N 2 O), methane (CH 4 ), and carbon monoxide (CO) species. Both N 2 O and CH 4 are both greenhouse gases, and the quantification of their concentration is crucial for global warming impact studies (climate models). CO is a good indicator of anthropogenic pollution because natural sources are comparatively small. The measurement of atmospheric pollutants like CO is a key to improving our understanding of urban air pollution processes. The CO

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C. A. M. Brenninkmeijer, P. J. Crutzen, H. Fischer, H. Güsten, W. Hans, G. Heinrich, J. Heintzenberg, M. Hermann, T. Immelmann, D. Kersting, M. Maiss, M. Nolle, A. Pitscheider, H. Pohlkamp, D. Scharffe, K. Specht, and A. Wiedensohler

1. Introduction Despite concern about environmental consequences of emissions from the growing fleet of aircraft, reliable impact assessments are not yet possible due to our deficient knowledge of details of physical and chemical processes in the upper troposphere and lower stratosphere and their interaction ( Schumann 1994 ). Clearly, not only aircraft emissions affect the chemistry in the region of the tropopause. Other anthropogenic activities, including the large-scale burning of forest and

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Joel R. Norris and Amato T. Evan

subgrid-scale cloud processes and produce cloud simulations that are inconsistent with one another and with observations (e.g., Clement et al. 2009 ; Klein et al. 2013 ). The shortcomings of theory and global climate models motivate the alternative approach of observing how clouds have changed in recent decades, a time period of rapidly increasing anthropogenic forcing and warming of the climate system. If patterns of multidecadal cloud variability likely to be associated with anthropogenically

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